Currently the kernel is not correctly updating the numa stats for
NR_FILE_PAGES and NR_SHMEM on THP migration. Fix that.
For NR_FILE_DIRTY and NR_ZONE_WRITE_PENDING, although at the moment
there is no need to handle THP migration as kernel still does not have
write support for file THP but to be more future proof, this patch adds
the THP support for those stats as well.
Link: https://lkml.kernel.org/r/20210108155813.2914586-2-shakeelb@google.com
Fixes: e71769ae52 ("mm: enable thp migration for shmem thp")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel updates the per-node NR_FILE_DIRTY stats on page migration
but not the memcg numa stats.
That was not an issue until recently the commit 5f9a4f4a70 ("mm:
memcontrol: add the missing numa_stat interface for cgroup v2") exposed
numa stats for the memcg.
So fix the file_dirty per-memcg numa stat.
Link: https://lkml.kernel.org/r/20210108155813.2914586-1-shakeelb@google.com
Fixes: 5f9a4f4a70 ("mm: memcontrol: add the missing numa_stat interface for cgroup v2")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There could be struct pages that are not backed by actual physical
memory. This can happen when the actual memory bank is not a multiple
of SECTION_SIZE or when an architecture does not register memory holes
reserved by the firmware as memblock.memory.
Such pages are currently initialized using init_unavailable_mem()
function that iterates through PFNs in holes in memblock.memory and if
there is a struct page corresponding to a PFN, the fields if this page
are set to default values and the page is marked as Reserved.
init_unavailable_mem() does not take into account zone and node the page
belongs to and sets both zone and node links in struct page to zero.
On a system that has firmware reserved holes in a zone above ZONE_DMA,
for instance in a configuration below:
# grep -A1 E820 /proc/iomem
7a17b000-7a216fff : Unknown E820 type
7a217000-7bffffff : System RAM
unset zone link in struct page will trigger
VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
because there are pages in both ZONE_DMA32 and ZONE_DMA (unset zone link
in struct page) in the same pageblock.
Update init_unavailable_mem() to use zone constraints defined by an
architecture to properly setup the zone link and use node ID of the
adjacent range in memblock.memory to set the node link.
Link: https://lkml.kernel.org/r/20210111194017.22696-3-rppt@kernel.org
Fixes: 73a6e474cb ("mm: memmap_init: iterate over memblock regions rather that check each PFN")
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.
As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.
Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The generic_fillattr() helper fills in the basic attributes associated
with an inode. Enable it to handle idmapped mounts. If the inode is
accessed through an idmapped mount map it into the mount's user
namespace before we store the uid and gid. If the initial user namespace
is passed nothing changes so non-idmapped mounts will see identical
behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-12-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it possible to handle acls on idmapped
mounts.
The vfs and the filesystems targeted by this first iteration make use of
posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to
translate basic posix access and default permissions such as the
ACL_USER and ACL_GROUP type according to the initial user namespace (or
the superblock's user namespace) to and from the caller's current user
namespace. Adapt these two helpers to handle idmapped mounts whereby we
either map from or into the mount's user namespace depending on in which
direction we're translating.
Similarly, cap_convert_nscap() is used by the vfs to translate user
namespace and non-user namespace aware filesystem capabilities from the
superblock's user namespace to the caller's user namespace. Enable it to
handle idmapped mounts by accounting for the mount's user namespace.
In addition the fileystems targeted in the first iteration of this patch
series make use of the posix_acl_chmod() and, posix_acl_update_mode()
helpers. Both helpers perform permission checks on the target inode. Let
them handle idmapped mounts. These two helpers are called when posix
acls are set by the respective filesystems to handle this case we extend
the ->set() method to take an additional user namespace argument to pass
the mount's user namespace down.
Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
When file attributes are changed most filesystems rely on the
setattr_prepare(), setattr_copy(), and notify_change() helpers for
initialization and permission checking. Let them handle idmapped mounts.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.
Helpers that perform checks on the ia_uid and ia_gid fields in struct
iattr assume that ia_uid and ia_gid are intended values and have already
been mapped correctly at the userspace-kernelspace boundary as we
already do today. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-8-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The inode_owner_or_capable() helper determines whether the caller is the
owner of the inode or is capable with respect to that inode. Allow it to
handle idmapped mounts. If the inode is accessed through an idmapped
mount it according to the mount's user namespace. Afterwards the checks
are identical to non-idmapped mounts. If the initial user namespace is
passed nothing changes so non-idmapped mounts will see identical
behavior as before.
Similarly, allow the inode_init_owner() helper to handle idmapped
mounts. It initializes a new inode on idmapped mounts by mapping the
fsuid and fsgid of the caller from the mount's user namespace. If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-7-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Add two simple helpers to check permissions on a file and path
respectively and convert over some callers. It simplifies quite a few
codepaths and also reduces the churn in later patches quite a bit.
Christoph also correctly points out that this makes codepaths (e.g.
ioctls) way easier to follow that would otherwise have to do more
complex argument passing than necessary.
Link: https://lore.kernel.org/r/20210121131959.646623-4-christian.brauner@ubuntu.com
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
This commit adds the starting address and number of pages to the vmalloc()
information dumped by way of vmalloc_dump_obj().
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <linux-mm@kvack.org>
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit adds vmalloc() support to mem_dump_obj(). Note that the
vmalloc_dump_obj() function combines the checking and dumping, in
contrast with the split between kmem_valid_obj() and kmem_dump_obj().
The reason for the difference is that the checking in the vmalloc()
case involves acquiring a global lock, and redundant acquisitions of
global locks should be avoided, even on not-so-fast paths.
Note that this change causes on-stack variables to be reported as
vmalloc() storage from kernel_clone() or similar, depending on the degree
of inlining that your compiler does. This is likely more helpful than
the earlier "non-paged (local) memory".
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <linux-mm@kvack.org>
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit makes mem_dump_obj() call out NULL and zero-sized pointers
specially instead of classifying them as non-paged memory.
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
There are kernel facilities such as per-CPU reference counts that give
error messages in generic handlers or callbacks, whose messages are
unenlightening. In the case of per-CPU reference-count underflow, this
is not a problem when creating a new use of this facility because in that
case the bug is almost certainly in the code implementing that new use.
However, trouble arises when deploying across many systems, which might
exercise corner cases that were not seen during development and testing.
Here, it would be really nice to get some kind of hint as to which of
several uses the underflow was caused by.
This commit therefore exposes a mem_dump_obj() function that takes
a pointer to memory (which must still be allocated if it has been
dynamically allocated) and prints available information on where that
memory came from. This pointer can reference the middle of the block as
well as the beginning of the block, as needed by things like RCU callback
functions and timer handlers that might not know where the beginning of
the memory block is. These functions and handlers can use mem_dump_obj()
to print out better hints as to where the problem might lie.
The information printed can depend on kernel configuration. For example,
the allocation return address can be printed only for slab and slub,
and even then only when the necessary debug has been enabled. For slab,
build with CONFIG_DEBUG_SLAB=y, and either use sizes with ample space
to the next power of two or use the SLAB_STORE_USER when creating the
kmem_cache structure. For slub, build with CONFIG_SLUB_DEBUG=y and
boot with slub_debug=U, or pass SLAB_STORE_USER to kmem_cache_create()
if more focused use is desired. Also for slub, use CONFIG_STACKTRACE
to enable printing of the allocation-time stack trace.
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>
Reported-by: Andrii Nakryiko <andrii@kernel.org>
[ paulmck: Convert to printing and change names per Joonsoo Kim. ]
[ paulmck: Move slab definition per Stephen Rothwell and kbuild test robot. ]
[ paulmck: Handle CONFIG_MMU=n case where vmalloc() is kmalloc(). ]
[ paulmck: Apply Vlastimil Babka feedback on slab.c kmem_provenance(). ]
[ paulmck: Extract more info from !SLUB_DEBUG per Joonsoo Kim. ]
[ paulmck: Explicitly check for small pointers per Naresh Kamboju. ]
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
In preparation for const-ifying the anonymous struct field of
'struct vm_fault', ensure that it is initialised using designated
initialisers.
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
In preparation for const-ifying the anonymous struct field of
'struct vm_fault', rework __collapse_huge_page_swapin() to avoid
continuously updating vmf.address and instead populate a new
'struct vm_fault' on the stack for each page being processed.
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will@kernel.org>
Rather than modifying the 'address' field of the 'struct vm_fault'
passed to do_set_pte(), leave that to identify the real faulting address
and pass in the virtual address to be mapped by the new pte as a
separate argument.
This makes FAULT_FLAG_PREFAULT redundant, as a prefault entry can be
identified simply by comparing the new address parameter with the
faulting address, so remove the redundant flag at the same time.
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will@kernel.org>
memblock_phys_alloc_try_nid function's comments has typo NUMA as MUMA.
Correct this typo.
Signed-off-by: Levi Yun <ppbuk5246@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Commit 5c0a85fad9 ("mm: make faultaround produce old ptes") changed
the "faultaround" behaviour to initialise prefaulted PTEs as 'old',
since this avoids vmscan wrongly assuming that they are hot, despite
having never been explicitly accessed by userspace. The change has been
shown to benefit numerous arm64 micro-architectures (with hardware
access flag) running Android, where both application launch latency and
direct reclaim time are significantly reduced (by 10%+ and ~80%
respectively).
Unfortunately, commit 315d09bf30 ("Revert "mm: make faultaround
produce old ptes"") reverted the change due to it being identified as
the cause of a ~6% regression in unixbench on x86. Experiments on a
variety of recent arm64 micro-architectures indicate that unixbench is
not affected by the original commit, which appears to yield a 0-1%
performance improvement.
Since one size does not fit all for the initial state of prefaulted
PTEs, introduce arch_wants_old_prefaulted_pte(), which allows an
architecture to opt-in to 'old' prefaulted PTEs at runtime based on
whatever criteria it may have.
Cc: Jan Kara <jack@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Will Deacon <will@kernel.org>
alloc_set_pte() has two users with different requirements: in the
faultaround code, it called from an atomic context and PTE page table
has to be preallocated. finish_fault() can sleep and allocate page table
as needed.
PTL locking rules are also strange, hard to follow and overkill for
finish_fault().
Let's untangle the mess. alloc_set_pte() has gone now. All locking is
explicit.
The price is some code duplication to handle huge pages in faultaround
path, but it should be fine, having overall improvement in readability.
Link: https://lore.kernel.org/r/20201229132819.najtavneutnf7ajp@box
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
[will: s/from from/from/ in comment; spotted by willy]
Signed-off-by: Will Deacon <will@kernel.org>
So technically there is nothing wrong with adding a pinned page to the
swap cache, but the pinning obviously means that the page can't actually
be free'd right now anyway, so it's a bit pointless.
However, the real problem is not with it being a bit pointless: the real
issue is that after we've added it to the swap cache, we'll try to unmap
the page. That will succeed, because the code in mm/rmap.c doesn't know
or care about pinned pages.
Even the unmapping isn't fatal per se, since the page will stay around
in memory due to the pinning, and we do hold the connection to it using
the swap cache. But when we then touch it next and take a page fault,
the logic in do_swap_page() will map it back into the process as a
possibly read-only page, and we'll then break the page association on
the next COW fault.
Honestly, this issue could have been fixed in any of those other places:
(a) we could refuse to unmap a pinned page (which makes conceptual
sense), or (b) we could make sure to re-map a pinned page writably in
do_swap_page(), or (c) we could just make do_wp_page() not COW the
pinned page (which was what we historically did before that "mm:
do_wp_page() simplification" commit).
But while all of them are equally valid models for breaking this chain,
not putting pinned pages into the swap cache in the first place is the
simplest one by far.
It's also the safest one: the reason why do_wp_page() was changed in the
first place was that getting the "can I re-use this page" wrong is so
fraught with errors. If you do it wrong, you end up with an incorrectly
shared page.
As a result, using "page_maybe_dma_pinned()" in either do_wp_page() or
do_swap_page() would be a serious bug since it is only a (very good)
heuristic. Re-using the page requires a hard black-and-white rule with
no room for ambiguity.
In contrast, saying "this page is very likely dma pinned, so let's not
add it to the swap cache and try to unmap it" is an obviously safe thing
to do, and if the heuristic might very rarely be a false positive, no
harm is done.
Fixes: 09854ba94c ("mm: do_wp_page() simplification")
Reported-and-tested-by: Martin Raiber <martin@urbackup.org>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No one checks the return value of memblock_free_all().
Make the return value void.
memblock_free_all() is used on mem_init() for each
architecture, and the total count of freed pages will be added
to _totalram_pages variable by calling totalram_pages_add().
so do not need to return total count of freed pages.
Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Format %pG expects a lower case 'p' in order to print the flags.
Fix it.
Link: https://lkml.kernel.org/r/20210108085202.4506-1-osalvador@suse.de
Fixes: 8295d535e2 ("mm,hwpoison: refactor get_any_page")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The huge page size is encoded for VM_FAULT_HWPOISON errors only. So if
we return VM_FAULT_HWPOISON, huge page size would just be ignored.
Link: https://lkml.kernel.org/r/20210107123449.38481-1-linmiaohe@huawei.com
Fixes: aa50d3a7aa ("Encode huge page size for VM_FAULT_HWPOISON errors")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit 236c32eb10 ("mm: migrate: clean up migrate_prep{_local}")',
do_migrate_pages can return uninitialized variable 'err' (which is
propagated to user-space as error) when 'from' and 'to' nodesets are
identical. This can be reproduced with LTP migrate_pages01, which calls
migrate_pages() with same set for both old/new_nodes.
Add 'err' initialization back.
Link: https://lkml.kernel.org/r/456a021c7ef3636d7668cec9dcb4a446a4244812.1609855564.git.jstancek@redhat.com
Fixes: 236c32eb10 ("mm: migrate: clean up migrate_prep{_local}")
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In VM_MAP_PUT_PAGES case, we should put pages and free array in vfree.
But we missed to set area->nr_pages in vmap(). So we would fail to put
pages in __vunmap() because area->nr_pages = 0.
Link: https://lkml.kernel.org/r/20210107123541.39206-1-linmiaohe@huawei.com
Fixes: b944afc9d6 ("mm: add a VM_MAP_PUT_PAGES flag for vmap")
Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The size of kasan_early_shadow_pte[] now is PTRS_PER_PTE which defined
to 512 for arm. This means that it only covers the prev Linux pte
entries, but not the HWTABLE pte entries for arm.
The reason it currently works is that the symbol kasan_early_shadow_page
immediately following kasan_early_shadow_pte in memory is page aligned,
which makes kasan_early_shadow_pte look like a 4KB size array. But we
can't ensure the order is always right with different compiler/linker,
or if more bss symbols are introduced.
We had a test with QEMU + vexpress：put a 512KB-size symbol with
attribute __section(".bss..page_aligned") after kasan_early_shadow_pte,
and poisoned it after kasan_early_init(). Then enabled CONFIG_KASAN, it
failed to boot up.
Link: https://lkml.kernel.org/r/20210109044622.8312-1-hailongliiu@yeah.net
Signed-off-by: Hailong Liu <liu.hailong6@zte.com.cn>
Signed-off-by: Ziliang Guo <guo.ziliang@zte.com.cn>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The trace point *trace_mm_page_alloc_zone_locked()* in __rmqueue() does
not currently cover all branches. Add the missing tracepoint and check
the page before do that.
[akpm@linux-foundation.org: use IS_ENABLED() to suppress warning]
Link: https://lkml.kernel.org/r/20201228132901.41523-1-carver4lio@163.com
Signed-off-by: Hailong liu <liu.hailong6@zte.com.cn>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
acquire_slab() fails if there is contention on the freelist of the page
(probably because some other CPU is concurrently freeing an object from
the page). In that case, it might make sense to look for a different page
(since there might be more remote frees to the page from other CPUs, and
we don't want contention on struct page).
However, the current code accidentally stops looking at the partial list
completely in that case. Especially on kernels without CONFIG_NUMA set,
this means that get_partial() fails and new_slab_objects() falls back to
new_slab(), allocating new pages. This could lead to an unnecessary
increase in memory fragmentation.
Link: https://lkml.kernel.org/r/20201228130853.1871516-1-jannh@google.com
Fixes: 7ced371971 ("slub: Acquire_slab() avoid loop")
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Way back it was a reasonable assumptions that iomem mappings never
change the pfn range they point at. But this has changed:
- gpu drivers dynamically manage their memory nowadays, invalidating
ptes with unmap_mapping_range when buffers get moved
- contiguous dma allocations have moved from dedicated carvetouts to
cma regions. This means if we miss the unmap the pfn might contain
pagecache or anon memory (well anything allocated with GFP_MOVEABLE)
- even /dev/mem now invalidates mappings when the kernel requests that
iomem region when CONFIG_IO_STRICT_DEVMEM is set, see 3234ac664a
("/dev/mem: Revoke mappings when a driver claims the region")
Accessing pfns obtained from ptes without holding all the locks is
therefore no longer a good idea. Fix this.
Since ioremap might need to manipulate pagetables too we need to drop
the pt lock and have a retry loop if we raced.
While at it, also add kerneldoc and improve the comment for the
vma_ops->access function. It's for accessing, not for moving the
memory from iomem to system memory, as the old comment seemed to
suggest.
References: 28b2ee20c7 ("access_process_vm device memory infrastructure")
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Benjamin Herrensmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20201127164131.2244124-8-daniel.vetter@ffwll.ch
It's the only user. This also garbage collects the CONFIG_FRAME_VECTOR
symbol from all over the tree (well just one place, somehow omap media
driver still had this in its Kconfig, despite not using it).
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Tomasz Figa <tfiga@chromium.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20201127164131.2244124-7-daniel.vetter@ffwll.ch
This is used by media/videbuf2 for persistent dma mappings, not just
for a single dma operation and then freed again, so needs
FOLL_LONGTERM.
Unfortunately current pup_locked doesn't support FOLL_LONGTERM due to
locking issues. Rework the code to pull the pup path out from the
mmap_sem critical section as suggested by Jason.
By relying entirely on the vma checks in pin_user_pages and follow_pfn
(for vm_flags and vma_is_fsdax) we can also streamline the code a lot.
Note that pin_user_pages_fast is a safe replacement despite the
seeming lack of checking for vma->vm_flasg & (VM_IO | VM_PFNMAP). Such
ptes are marked with pte_mkspecial (which pup_fast rejects in the
fastpath), and only architectures supporting that support the
pin_user_pages_fast fastpath.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Tomasz Figa <tfiga@chromium.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-media@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20201127164131.2244124-6-daniel.vetter@ffwll.ch
Ever since commit 2a9127fcf2 ("mm: rewrite wait_on_page_bit_common()
logic") we've had some very occasional reports of BUG_ON(PageWriteback)
in write_cache_pages(), which we thought we already fixed in commit
073861ed77 ("mm: fix VM_BUG_ON(PageTail) and BUG_ON(PageWriteback)").
But syzbot just reported another one, even with that commit in place.
And it turns out that there's a simpler way to trigger the BUG_ON() than
the one Hugh found with page re-use. It all boils down to the fact that
the page writeback is ostensibly serialized by the page lock, but that
isn't actually really true.
Yes, the people _setting_ writeback all do so under the page lock, but
the actual clearing of the bit - and waking up any waiters - happens
without any page lock.
This gives us this fairly simple race condition:
CPU1 = end previous writeback
CPU2 = start new writeback under page lock
CPU3 = write_cache_pages()
CPU1 CPU2 CPU3
---- ---- ----
end_page_writeback()
test_clear_page_writeback(page)
... delayed...
lock_page();
set_page_writeback()
unlock_page()
lock_page()
wait_on_page_writeback();
wake_up_page(page, PG_writeback);
.. wakes up CPU3 ..
BUG_ON(PageWriteback(page));
where the BUG_ON() happens because we woke up the PG_writeback bit
becasue of the _previous_ writeback, but a new one had already been
started because the clearing of the bit wasn't actually atomic wrt the
actual wakeup or serialized by the page lock.
The reason this didn't use to happen was that the old logic in waiting
on a page bit would just loop if it ever saw the bit set again.
The nice proper fix would probably be to get rid of the whole "wait for
writeback to clear, and then set it" logic in the writeback path, and
replace it with an atomic "wait-to-set" (ie the same as we have for page
locking: we set the page lock bit with a single "lock_page()", not with
"wait for lock bit to clear and then set it").
However, out current model for writeback is that the waiting for the
writeback bit is done by the generic VFS code (ie write_cache_pages()),
but the actual setting of the writeback bit is done much later by the
filesystem ".writepages()" function.
IOW, to make the writeback bit have that same kind of "wait-to-set"
behavior as we have for page locking, we'd have to change our roughly
~50 different writeback functions. Painful.
Instead, just make "wait_on_page_writeback()" loop on the very unlikely
situation that the PG_writeback bit is still set, basically re-instating
the old behavior. This is very non-optimal in case of contention, but
since we only ever set the bit under the page lock, that situation is
controlled.
Reported-by: syzbot+2fc0712f8f8b8b8fa0ef@syzkaller.appspotmail.com
Fixes: 2a9127fcf2 ("mm: rewrite wait_on_page_bit_common() logic")
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's convenient to have page->objects initialized before calling into
account_slab_page(). In particular, this information can be used to
pre-alloc the obj_cgroup vector.
Let's call account_slab_page() a bit later, after the initialization of
page->objects.
This commit doesn't bring any functional change, but is required for
further optimizations.
[akpm@linux-foundation.org: undo changes needed by forthcoming mm-memcg-slab-pre-allocate-obj_cgroups-for-slab-caches-with-slab_account.patch]
Link: https://lkml.kernel.org/r/20201110195753.530157-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I'm not sure if I'm completely missing something here, but AFAIKS the
reference to the mysterious "COW SMC race" confuses the issue. The
original changelog and mailing list thread didn't help me either.
This SMC race is where the problem was detected, but isn't the general
problem bigger and more obvious: that the new PTE could be picked up at
any time by any TLB while entries for the old PTE exist in other TLBs
before the TLB flush takes effect?
The case where the iTLB and dTLB of a CPU are pointing at different pages
is an interesting one but follows from the general problem.
The other (minor) thing with the comment I think it makes it a bit clearer
to say what the old code was doing (i.e., it avoids the race as opposed to
what?).
References: 4ce072f1fa ("mm: fix a race condition under SMC + COW")
Link: https://lkml.kernel.org/r/20201215121119.351650-1-npiggin@gmail.com
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
VMware observed a performance regression during memmap init on their
platform, and bisected to commit 73a6e474cb ("mm: memmap_init:
iterate over memblock regions rather that check each PFN") causing it.
Before the commit:
[0.033176] Normal zone: 1445888 pages used for memmap
[0.033176] Normal zone: 89391104 pages, LIFO batch:63
[0.035851] ACPI: PM-Timer IO Port: 0x448
With commit
[0.026874] Normal zone: 1445888 pages used for memmap
[0.026875] Normal zone: 89391104 pages, LIFO batch:63
[2.028450] ACPI: PM-Timer IO Port: 0x448
The root cause is the current memmap defer init doesn't work as expected.
Before, memmap_init_zone() was used to do memmap init of one whole zone,
to initialize all low zones of one numa node, but defer memmap init of
the last zone in that numa node. However, since commit 73a6e474cb,
function memmap_init() is adapted to iterater over memblock regions
inside one zone, then call memmap_init_zone() to do memmap init for each
region.
E.g, on VMware's system, the memory layout is as below, there are two
memory regions in node 2. The current code will mistakenly initialize the
whole 1st region [mem 0xab00000000-0xfcffffffff], then do memmap defer to
iniatialize only one memmory section on the 2nd region [mem
0x10000000000-0x1033fffffff]. In fact, we only expect to see that there's
only one memory section's memmap initialized. That's why more time is
costed at the time.
[ 0.008842] ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff]
[ 0.008842] ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0xbfffffff]
[ 0.008843] ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x55ffffffff]
[ 0.008844] ACPI: SRAT: Node 1 PXM 1 [mem 0x5600000000-0xaaffffffff]
[ 0.008844] ACPI: SRAT: Node 2 PXM 2 [mem 0xab00000000-0xfcffffffff]
[ 0.008845] ACPI: SRAT: Node 2 PXM 2 [mem 0x10000000000-0x1033fffffff]
Now, let's add a parameter 'zone_end_pfn' to memmap_init_zone() to pass
down the real zone end pfn so that defer_init() can use it to judge
whether defer need be taken in zone wide.
Link: https://lkml.kernel.org/r/20201223080811.16211-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20201223080811.16211-2-bhe@redhat.com
Fixes: commit 73a6e474cb ("mm: memmap_init: iterate over memblock regions rather that check each PFN")
Signed-off-by: Baoquan He <bhe@redhat.com>
Reported-by: Rahul Gopakumar <gopakumarr@vmware.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
syzbot reported the deadlock here [1]. The issue is in hugetlb cow
error handling when there are not enough huge pages for the faulting
task which took the original reservation. It is possible that other
(child) tasks could have consumed pages associated with the reservation.
In this case, we want the task which took the original reservation to
succeed. So, we unmap any associated pages in children so that they can
be used by the faulting task that owns the reservation.
The unmapping code needs to hold i_mmap_rwsem in write mode. However,
due to commit c0d0381ade ("hugetlbfs: use i_mmap_rwsem for more pmd
sharing synchronization") we are already holding i_mmap_rwsem in read
mode when hugetlb_cow is called.
Technically, i_mmap_rwsem does not need to be held in read mode for COW
mappings as they can not share pmd's. Modifying the fault code to not
take i_mmap_rwsem in read mode for COW (and other non-sharable) mappings
is too involved for a stable fix.
Instead, we simply drop the hugetlb_fault_mutex and i_mmap_rwsem before
unmapping. This is OK as it is technically not needed. They are
reacquired after unmapping as expected by calling code. Since this is
done in an uncommon error path, the overhead of dropping and reacquiring
mutexes is acceptable.
While making changes, remove redundant BUG_ON after unmap_ref_private.
[1] https://lkml.kernel.org/r/000000000000b73ccc05b5cf8558@google.com
Link: https://lkml.kernel.org/r/4c5781b8-3b00-761e-c0c7-c5edebb6ec1a@oracle.com
Fixes: c0d0381ade ("hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: syzbot+5eee4145df3c15e96625@syzkaller.appspotmail.com
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vdpa sim refactoring
virtio mem Big Block Mode support
misc cleanus, fixes
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio updates from Michael Tsirkin:
- vdpa sim refactoring
- virtio mem: Big Block Mode support
- misc cleanus, fixes
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (61 commits)
vdpa: Use simpler version of ida allocation
vdpa: Add missing comment for virtqueue count
uapi: virtio_ids: add missing device type IDs from OASIS spec
uapi: virtio_ids.h: consistent indentions
vhost scsi: fix error return code in vhost_scsi_set_endpoint()
virtio_ring: Fix two use after free bugs
virtio_net: Fix error code in probe()
virtio_ring: Cut and paste bugs in vring_create_virtqueue_packed()
tools/virtio: add barrier for aarch64
tools/virtio: add krealloc_array
tools/virtio: include asm/bug.h
vdpa/mlx5: Use write memory barrier after updating CQ index
vdpa: split vdpasim to core and net modules
vdpa_sim: split vdpasim_virtqueue's iov field in out_iov and in_iov
vdpa_sim: make vdpasim->buffer size configurable
vdpa_sim: use kvmalloc to allocate vdpasim->buffer
vdpa_sim: set vringh notify callback
vdpa_sim: add set_config callback in vdpasim_dev_attr
vdpa_sim: add get_config callback in vdpasim_dev_attr
vdpa_sim: make 'config' generic and usable for any device type
...
The reason cache merging is disabled with KASAN is because KASAN puts its
metadata right after the allocated object. When the merged caches have
slightly different sizes, the metadata ends up in different places, which
KASAN doesn't support.
It might be possible to adjust the metadata allocation algorithm and make
it friendly to the cache merging code. Instead this change takes a simpler
approach and allows merging caches when no metadata is present. Which is
the case for hardware tag-based KASAN with kasan.mode=prod.
Link: https://lkml.kernel.org/r/37497e940bfd4b32c0a93a702a9ae4cf061d5392.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Ia114847dfb2244f297d2cb82d592bf6a07455dba
Co-developed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KASAN marks caches that are sanitized with the SLAB_KASAN cache flag.
Currently if the metadata that is appended after the object (stores e.g.
stack trace ids) doesn't fit into KMALLOC_MAX_SIZE (can only happen with
SLAB, see the comment in the patch), KASAN turns off sanitization
completely.
With this change sanitization of the object data is always enabled.
However the metadata is only stored when it fits. Instead of checking for
SLAB_KASAN flag accross the code to find out whether the metadata is
there, use cache->kasan_info.alloc/free_meta_offset. As 0 can be a valid
value for free_meta_offset, introduce KASAN_NO_FREE_META as an indicator
that the free metadata is missing.
Without this change all sanitized KASAN objects would be put into
quarantine with generic KASAN. With this change, only the objects that
have metadata (i.e. when it fits) are put into quarantine, the rest is
freed right away.
Along the way rework __kasan_cache_create() and add claryfying comments.
Link: https://lkml.kernel.org/r/aee34b87a5e4afe586c2ac6a0b32db8dc4dcc2dc.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Icd947e2bea054cb5cfbdc6cf6652227d97032dcb
Co-developed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
set_tag() already ignores the tag for the generic mode, so just call it
as is. Add a check for the generic mode to assign_tag(), and simplify its
call in ____kasan_kmalloc().
Link: https://lkml.kernel.org/r/121eeab245f98555862b289d2ba9269c868fbbcf.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I18905ca78fb4a3d60e1a34a4ca00247272480438
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Declare the kasan_enabled static key in include/linux/kasan.h and in
include/linux/mm.h and check it in all kasan annotations. This allows to
avoid any slowdown caused by function calls when kasan_enabled is
disabled.
Link: https://lkml.kernel.org/r/9f90e3c0aa840dbb4833367c2335193299f69023.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I2589451d3c96c97abbcbf714baabe6161c6f153e
Co-developed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hardware tag-based KASAN mode is intended to eventually be used in
production as a security mitigation. Therefore there's a need for finer
control over KASAN features and for an existence of a kill switch.
This change adds a few boot parameters for hardware tag-based KASAN that
allow to disable or otherwise control particular KASAN features.
The features that can be controlled are:
1. Whether KASAN is enabled at all.
2. Whether KASAN collects and saves alloc/free stacks.
3. Whether KASAN panics on a detected bug or not.
With this change a new boot parameter kasan.mode allows to choose one of
three main modes:
- kasan.mode=off - KASAN is disabled, no tag checks are performed
- kasan.mode=prod - only essential production features are enabled
- kasan.mode=full - all KASAN features are enabled
The chosen mode provides default control values for the features mentioned
above. However it's also possible to override the default values by
providing:
- kasan.stacktrace=off/on - enable alloc/free stack collection
(default: on for mode=full, otherwise off)
- kasan.fault=report/panic - only report tag fault or also panic
(default: report)
If kasan.mode parameter is not provided, it defaults to full when
CONFIG_DEBUG_KERNEL is enabled, and to prod otherwise.
It is essential that switching between these modes doesn't require
rebuilding the kernel with different configs, as this is required by
the Android GKI (Generic Kernel Image) initiative [1].
[1] https://source.android.com/devices/architecture/kernel/generic-kernel-image
[andreyknvl@google.com: don't use read-only static keys]
Link: https://lkml.kernel.org/r/f2ded589eba1597f7360a972226083de9afd86e2.1607537948.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/cb093613879d8d8841173f090133eddeb4c35f1f.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/If7d37003875b2ed3e0935702c8015c223d6416a4
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using (un)poison_range() or check_invalid_free() currently results in
function calls. Move their definitions to mm/kasan/kasan.h and turn them
into static inline functions for hardware tag-based mode to avoid
unneeded function calls.
Link: https://lkml.kernel.org/r/7007955b69eb31b5376a7dc1e0f4ac49138504f2.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Ia9d8191024a12d1374675b3d27197f10193f50bb
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's the external annotation kasan_unpoison_slab() that is currently
defined as static inline and uses kasan_unpoison_range(). Open-code this
function in mempool.c. Otherwise with an upcoming change this function
will result in an unnecessary function call.
Link: https://lkml.kernel.org/r/131a6694a978a9a8b150187e539eecc8bcbf759b.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Ia7c8b659f79209935cbaab3913bf7f082cc43a0e
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using random_tag() currently results in a function call. Move its
definition to mm/kasan/kasan.h and turn it into a static inline function
for hardware tag-based mode to avoid uneeded function calls.
Link: https://lkml.kernel.org/r/be438471690e351e1d792e6bb432e8c03ccb15d3.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Iac5b2faf9a912900e16cca6834d621f5d4abf427
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using kasan_reset_tag() currently results in a function call. As it's
called quite often from the allocator code, this leads to a noticeable
slowdown. Move it to include/linux/kasan.h and turn it into a static
inline function. Also remove the now unneeded reset_tag() internal KASAN
macro and use kasan_reset_tag() instead.
Link: https://lkml.kernel.org/r/6940383a3a9dfb416134d338d8fac97a9ebb8686.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I4d2061acfe91d480a75df00b07c22d8494ef14b5
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's no need for __kasan_unpoison_stack() helper, as it's only
currently used in a single place. Removing it also removes unneeded
arithmetic.
No functional changes.
Link: https://lkml.kernel.org/r/93e78948704a42ea92f6248ff8a725613d721161.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Ie5ba549d445292fe629b4a96735e4034957bcc50
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's a config option CONFIG_KASAN_STACK that has to be enabled for
KASAN to use stack instrumentation and perform validity checks for
stack variables.
There's no need to unpoison stack when CONFIG_KASAN_STACK is not enabled.
Only call kasan_unpoison_task_stack[_below]() when CONFIG_KASAN_STACK is
enabled.
Note, that CONFIG_KASAN_STACK is an option that is currently always
defined when CONFIG_KASAN is enabled, and therefore has to be tested
with #if instead of #ifdef.
Link: https://lkml.kernel.org/r/d09dd3f8abb388da397fd11598c5edeaa83fe559.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/If8a891e9fe01ea543e00b576852685afec0887e3
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "kasan: boot parameters for hardware tag-based mode", v4.
=== Overview
Hardware tag-based KASAN mode [1] is intended to eventually be used in
production as a security mitigation. Therefore there's a need for finer
control over KASAN features and for an existence of a kill switch.
This patchset adds a few boot parameters for hardware tag-based KASAN that
allow to disable or otherwise control particular KASAN features, as well
as provides some initial optimizations for running KASAN in production.
There's another planned patchset what will further optimize hardware
tag-based KASAN, provide proper benchmarking and tests, and will fully
enable tag-based KASAN for production use.
Hardware tag-based KASAN relies on arm64 Memory Tagging Extension (MTE)
[2] to perform memory and pointer tagging. Please see [3] and [4] for
detailed analysis of how MTE helps to fight memory safety problems.
The features that can be controlled are:
1. Whether KASAN is enabled at all.
2. Whether KASAN collects and saves alloc/free stacks.
3. Whether KASAN panics on a detected bug or not.
The patch titled "kasan: add and integrate kasan boot parameters" of this
series adds a few new boot parameters.
kasan.mode allows to choose one of three main modes:
- kasan.mode=off - KASAN is disabled, no tag checks are performed
- kasan.mode=prod - only essential production features are enabled
- kasan.mode=full - all KASAN features are enabled
The chosen mode provides default control values for the features mentioned
above. However it's also possible to override the default values by
providing:
- kasan.stacktrace=off/on - enable stacks collection
(default: on for mode=full, otherwise off)
- kasan.fault=report/panic - only report tag fault or also panic
(default: report)
If kasan.mode parameter is not provided, it defaults to full when
CONFIG_DEBUG_KERNEL is enabled, and to prod otherwise.
It is essential that switching between these modes doesn't require
rebuilding the kernel with different configs, as this is required by
the Android GKI (Generic Kernel Image) initiative.
=== Benchmarks
For now I've only performed a few simple benchmarks such as measuring
kernel boot time and slab memory usage after boot. There's an upcoming
patchset which will optimize KASAN further and include more detailed
benchmarking results.
The benchmarks were performed in QEMU and the results below exclude the
slowdown caused by QEMU memory tagging emulation (as it's different from
the slowdown that will be introduced by hardware and is therefore
irrelevant).
KASAN_HW_TAGS=y + kasan.mode=off introduces no performance or memory
impact compared to KASAN_HW_TAGS=n.
kasan.mode=prod (manually excluding tagging) introduces 3% of performance
and no memory impact (except memory used by hardware to store tags)
compared to kasan.mode=off.
kasan.mode=full has about 40% performance and 30% memory impact over
kasan.mode=prod. Both come from alloc/free stack collection.
=== Notes
This patchset is available here:
https://github.com/xairy/linux/tree/up-boot-mte-v4
This patchset is based on v11 of "kasan: add hardware tag-based mode for
arm64" patchset [1].
For testing in QEMU hardware tag-based KASAN requires:
1. QEMU built from master [6] (use "-machine virt,mte=on -cpu max" arguments
to run).
2. GCC version 10.
[1] https://lore.kernel.org/linux-arm-kernel/cover.1606161801.git.andreyknvl@google.com/T/#t
[2] https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/enhancing-memory-safety
[3] https://arxiv.org/pdf/1802.09517.pdf
[4] https://github.com/microsoft/MSRC-Security-Research/blob/master/papers/2020/Security%20analysis%20of%20memory%20tagging.pdf
[5] https://source.android.com/devices/architecture/kernel/generic-kernel-image
[6] https://github.com/qemu/qemu
=== Tags
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
This patch (of 19):
Move get_free_info() call into quarantine_put() to simplify the call site.
No functional changes.
Link: https://lkml.kernel.org/r/cover.1606162397.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/312d0a3ef92cc6dc4fa5452cbc1714f9393ca239.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Iab0f04e7ebf8d83247024b7190c67c3c34c7940f
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kernel allocator code accesses metadata for slab objects, that may lie
out-of-bounds of the object itself, or be accessed when an object is
freed. Such accesses trigger tag faults and lead to false-positive
reports with hardware tag-based KASAN.
Software KASAN modes disable instrumentation for allocator code via
KASAN_SANITIZE Makefile macro, and rely on kasan_enable/disable_current()
annotations which are used to ignore KASAN reports.
With hardware tag-based KASAN neither of those options are available, as
it doesn't use compiler instrumetation, no tag faults are ignored, and MTE
is disabled after the first one.
Instead, reset tags when accessing metadata (currently only for SLUB).
Link: https://lkml.kernel.org/r/a0f3cefbc49f34c843b664110842de4db28179d0.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add error reporting for hardware tag-based KASAN. When
CONFIG_KASAN_HW_TAGS is enabled, print KASAN report from the arm64 tag
fault handler.
SAS bits aren't set in ESR for all faults reported in EL1, so it's
impossible to find out the size of the access the caused the fault. Adapt
KASAN reporting code to handle this case.
Link: https://lkml.kernel.org/r/b559c82b6a969afedf53b4694b475f0234067a1a.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide implementation of KASAN functions required for the hardware
tag-based mode. Those include core functions for memory and pointer
tagging (tags_hw.c) and bug reporting (report_tags_hw.c). Also adapt
common KASAN code to support the new mode.
Link: https://lkml.kernel.org/r/cfd0fbede579a6b66755c98c88c108e54f9c56bf.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch add a set of arch_*() memory tagging helpers currently only
defined for arm64 when hardware tag-based KASAN is enabled. These helpers
will be used by KASAN runtime to implement the hardware tag-based mode.
The arch-level indirection level is introduced to simplify adding hardware
tag-based KASAN support for other architectures in the future by defining
the appropriate arch_*() macros.
Link: https://lkml.kernel.org/r/fc9e5bb71201c03131a2fc00a74125723568dda9.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_reserved_area() memsets the pages belonging to a given memory area.
As that memory hasn't been allocated via page_alloc, the KASAN tags that
those pages have are 0x00. As the result the memset might result in a tag
mismatch.
Untag the address to avoid spurious faults.
Link: https://lkml.kernel.org/r/ebef6425f4468d063e2f09c1b62ccbb2236b71d3.1606161801.git.andreyknvl@google.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
Rework print_memory_metadata() to make it agnostic with regard to the way
metadata is stored. Allow providing a separate metadata_fetch_row()
implementation for each KASAN mode. Hardware tag-based KASAN will provide
its own implementation that doesn't use shadow memory.
No functional changes for software modes.
Link: https://lkml.kernel.org/r/5fb1ec0152bb1f521505017800387ec3e36ffe18.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
Hardware tag-based KASAN won't be using shadow memory, but will reuse
these macros. Rename "SHADOW" to implementation-neutral "META".
No functional changes.
Link: https://lkml.kernel.org/r/f96244ec59dc17db35173ec352c5592b14aefaf8.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
Hardware tag-based KASAN won't be using shadow memory, but will reuse this
function. Rename "shadow" to implementation-neutral "metadata".
No functional changes.
Link: https://lkml.kernel.org/r/dd955c5aadaee16aef451a6189d19172166a23f5.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
Hardware tag-based KASAN won't be using shadow memory, but will reuse this
function. Rename "shadow" to implementation-neutral "metadata".
No functional changes.
Link: https://lkml.kernel.org/r/370466fba590a4596b55ffd38adfd990f8886db4.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Software tag-based KASAN mode is fully initialized with kasan_init_tags(),
while the generic mode only requires kasan_init(). Move the
initialization message for tag-based mode into kasan_init_tags().
Also fix pr_fmt() usage for KASAN code: generic.c doesn't need it as it
doesn't use any printing functions; tag-based mode should use "kasan:"
instead of KBUILD_MODNAME (which stands for file name).
Link: https://lkml.kernel.org/r/29a30ea4e1750450dd1f693d25b7b6cb05913ecf.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
Hardware tag-based KASAN won't use kasan_depth. Only define and use it
when one of the software KASAN modes are enabled.
No functional changes for software modes.
Link: https://lkml.kernel.org/r/e16f15aeda90bc7fb4dfc2e243a14b74cc5c8219.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
For software KASAN modes the check is based on the value in the shadow
memory. Hardware tag-based KASAN won't be using shadow, so hide the
implementation of the check in check_invalid_free().
Also simplify the code for software tag-based mode.
No functional changes for software modes.
Link: https://lkml.kernel.org/r/d01534a4b977f97d87515dc590e6348e1406de81.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename generic_report.c to report_generic.c and tags_report.c to
report_sw_tags.c, as their content is more relevant to report.c file.
Also rename tags.c to sw_tags.c to better reflect that this file contains
code for software tag-based mode.
No functional changes.
Link: https://lkml.kernel.org/r/a6105d416da97d389580015afed66c4c3cfd4c08.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Define KASAN_MEMORY_PER_SHADOW_PAGE as (KASAN_GRANULE_SIZE << PAGE_SHIFT),
which is the same as (KASAN_GRANULE_SIZE * PAGE_SIZE) for software modes
that use shadow memory, and use it across KASAN code to simplify it.
Link: https://lkml.kernel.org/r/8329391cfe14b5cffd3decf3b5c535b6ce21eef6.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
The new mode won't be using shadow memory. Move all shadow-related code
to shadow.c, which is only enabled for software KASAN modes that use
shadow memory.
No functional changes for software modes.
Link: https://lkml.kernel.org/r/17d95cfa7d5cf9c4fcd9bf415f2a8dea911668df.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
The new mode won't be using shadow memory, so only build init.c that
contains shadow initialization code for software modes.
No functional changes for software modes.
Link: https://lkml.kernel.org/r/bae0a6a35b7a9b1a443803c1a55e6e3fecc311c9.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
The new mode won't be using shadow memory, but will still use the concept
of memory granules. Each memory granule maps to a single metadata entry:
8 bytes per one shadow byte for generic mode, 16 bytes per one shadow byte
for software tag-based mode, and 16 bytes per one allocation tag for
hardware tag-based mode.
Rename KASAN_SHADOW_SCALE_SIZE to KASAN_GRANULE_SIZE, and
KASAN_SHADOW_MASK to KASAN_GRANULE_MASK.
Also use MASK when used as a mask, otherwise use SIZE.
No functional changes.
Link: https://lkml.kernel.org/r/939b5754e47f528a6e6a6f28ffc5815d8d128033.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
Group all vmalloc-related function declarations in include/linux/kasan.h,
and their implementations in mm/kasan/common.c.
No functional changes.
Link: https://lkml.kernel.org/r/80a6fdd29b039962843bd6cf22ce2643a7c8904e.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "kasan: add hardware tag-based mode for arm64", v11.
This patchset adds a new hardware tag-based mode to KASAN [1]. The new
mode is similar to the existing software tag-based KASAN, but relies on
arm64 Memory Tagging Extension (MTE) [2] to perform memory and pointer
tagging (instead of shadow memory and compiler instrumentation).
This patchset is co-developed and tested by
Vincenzo Frascino <vincenzo.frascino@arm.com>.
This patchset is available here:
https://github.com/xairy/linux/tree/up-kasan-mte-v11
For testing in QEMU hardware tag-based KASAN requires:
1. QEMU built from master [4] (use "-machine virt,mte=on -cpu max" arguments
to run).
2. GCC version 10.
[1] https://www.kernel.org/doc/html/latest/dev-tools/kasan.html
[2] https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/enhancing-memory-safety
[3] git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux for-next/mte
[4] https://github.com/qemu/qemu
====== Overview
The underlying ideas of the approach used by hardware tag-based KASAN are:
1. By relying on the Top Byte Ignore (TBI) arm64 CPU feature, pointer tags
are stored in the top byte of each kernel pointer.
2. With the Memory Tagging Extension (MTE) arm64 CPU feature, memory tags
for kernel memory allocations are stored in a dedicated memory not
accessible via normal instuctions.
3. On each memory allocation, a random tag is generated, embedded it into
the returned pointer, and the corresponding memory is tagged with the
same tag value.
4. With MTE the CPU performs a check on each memory access to make sure
that the pointer tag matches the memory tag.
5. On a tag mismatch the CPU generates a tag fault, and a KASAN report is
printed.
Same as other KASAN modes, hardware tag-based KASAN is intended as a
debugging feature at this point.
====== Rationale
There are two main reasons for this new hardware tag-based mode:
1. Previously implemented software tag-based KASAN is being successfully
used on dogfood testing devices due to its low memory overhead (as
initially planned). The new hardware mode keeps the same low memory
overhead, and is expected to have significantly lower performance
impact, due to the tag checks being performed by the hardware.
Therefore the new mode can be used as a better alternative in dogfood
testing for hardware that supports MTE.
2. The new mode lays the groundwork for the planned in-kernel MTE-based
memory corruption mitigation to be used in production.
====== Technical details
Considering the implementation perspective, hardware tag-based KASAN is
almost identical to the software mode. The key difference is using MTE
for assigning and checking tags.
Compared to the software mode, the hardware mode uses 4 bits per tag, as
dictated by MTE. Pointer tags are stored in bits [56:60), the top 4 bits
have the normal value 0xF. Having less distict tags increases the
probablity of false negatives (from ~1/256 to ~1/16) in certain cases.
Only synchronous exceptions are set up and used by hardware tag-based KASAN.
====== Benchmarks
Note: all measurements have been performed with software emulation of Memory
Tagging Extension, performance numbers for hardware tag-based KASAN on the
actual hardware are expected to be better.
Boot time [1]:
* 2.8 sec for clean kernel
* 5.7 sec for hardware tag-based KASAN
* 11.8 sec for software tag-based KASAN
* 11.6 sec for generic KASAN
Slab memory usage after boot [2]:
* 7.0 kb for clean kernel
* 9.7 kb for hardware tag-based KASAN
* 9.7 kb for software tag-based KASAN
* 41.3 kb for generic KASAN
Measurements have been performed with:
* defconfig-based configs
* Manually built QEMU master
* QEMU arguments: -machine virt,mte=on -cpu max
* CONFIG_KASAN_STACK_ENABLE disabled
* CONFIG_KASAN_INLINE enabled
* clang-10 as the compiler and gcc-10 as the assembler
[1] Time before the ext4 driver is initialized.
[2] Measured as `cat /proc/meminfo | grep Slab`.
====== Notes
The cover letter for software tag-based KASAN patchset can be found here:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0116523cfffa62aeb5aa3b85ce7419f3dae0c1b8
===== Tags
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
This patch (of 41):
Don't mention "GNU General Public License version 2" text explicitly, as
it's already covered by the SPDX-License-Identifier.
Link: https://lkml.kernel.org/r/cover.1606161801.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/6ea9f5f4aa9dbbffa0d0c0a780b37699a4531034.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge still more updates from Andrew Morton:
"18 patches.
Subsystems affected by this patch series: mm (memcg and cleanups) and
epoll"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm/Kconfig: fix spelling mistake "whats" -> "what's"
selftests/filesystems: expand epoll with epoll_pwait2
epoll: wire up syscall epoll_pwait2
epoll: add syscall epoll_pwait2
epoll: convert internal api to timespec64
epoll: eliminate unnecessary lock for zero timeout
epoll: replace gotos with a proper loop
epoll: pull all code between fetch_events and send_event into the loop
epoll: simplify and optimize busy loop logic
epoll: move eavail next to the list_empty_careful check
epoll: pull fatal signal checks into ep_send_events()
epoll: simplify signal handling
epoll: check for events when removing a timed out thread from the wait queue
mm/memcontrol:rewrite mem_cgroup_page_lruvec()
mm, kvm: account kvm_vcpu_mmap to kmemcg
mm/memcg: remove unused definitions
mm/memcg: warning on !memcg after readahead page charged
mm/memcg: bail early from swap accounting if memcg disabled
There is a spelling mistake in the Kconfig help text. Fix it.
Link: https://lkml.kernel.org/r/20201217172717.58203-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mem_cgroup_page_lruvec() in memcontrol.c and mem_cgroup_lruvec() in
memcontrol.h is very similar except for the param(page and memcg) which
also can be convert to each other.
So rewrite mem_cgroup_page_lruvec() with mem_cgroup_lruvec().
[alex.shi@linux.alibaba.com: add missed warning in mem_cgroup_lruvec]
Link: https://lkml.kernel.org/r/94f17bb7-ec61-5b72-3555-fabeb5a4d73b@linux.alibaba.com
[lstoakes@gmail.com: warn on missing memcg on mem_cgroup_page_lruvec()]
Link: https://lkml.kernel.org/r/20201125112202.387009-1-lstoakes@gmail.com
Link: https://lkml.kernel.org/r/20201108143731.GA74138@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add VM_WARN_ON_ONCE_PAGE() macro.
Since readahead page is charged on memcg too, in theory we don't have to
check this exception now. Before safely remove them all, add a warning
for the unexpected !memcg.
Link: https://lkml.kernel.org/r/1604283436-18880-3-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "bail out early for memcg disable".
These 2 patches are indepenedent from per memcg lru lock, and may
encounter unexpected warning, so let's move out them from per memcg
lru locking patchset.
This patch (of 2):
We could bail out early when memcg wasn't enabled.
Link: https://lkml.kernel.org/r/1604283436-18880-1-git-send-email-alex.shi@linux.alibaba.com
Link: https://lkml.kernel.org/r/1604283436-18880-2-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If iter->count is 0 and iocb->ki_pos is page aligned, this causes
nr_pages to be 0.
Then in generic_file_buffered_read_get_pages() find_get_pages_contig()
returns 0 - because we asked for 0 pages, so we call
generic_file_buffered_read_no_cached_page() which attempts to add a page
to the page cache, which fails with -EEXIST, and then we loop. Oops...
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Reported-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
virtio-mem soon wants to use offline_and_remove_memory() memory that
exceeds a single Linux memory block (memory_block_size_bytes()). Let's
remove that restriction.
Let's remember the old state and try to restore that if anything goes
wrong. While re-onlining can, in general, fail, it's highly unlikely to
happen (usually only when a notifier fails to allocate memory, and these
are rather rare).
This will be used by virtio-mem to offline+remove memory ranges that are
bigger than a single memory block - for example, with a device block
size of 1 GiB (e.g., gigantic pages in the hypervisor) and a Linux memory
block size of 128MB.
While we could compress the state into 2 bit, using 8 bit is much
easier.
This handling is similar, but different to acpi_scan_try_to_offline():
a) We don't try to offline twice. I am not sure if this CONFIG_MEMCG
optimization is still relevant - it should only apply to ZONE_NORMAL
(where we have no guarantees). If relevant, we can always add it.
b) acpi_scan_try_to_offline() simply onlines all memory in case
something goes wrong. It doesn't restore previous online type. Let's do
that, so we won't overwrite what e.g., user space configured.
Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201112133815.13332-28-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
- Only enable char/agp uapi when CONFIG_DRM_LEGACY is set
Cross-subsystem Changes:
- vma_set_file helper to make vma->vm_file changing less brittle,
acked by Andrew
Core Changes:
- dma-buf heaps improvements
- pass full atomic modeset state to driver callbacks
- shmem helpers: cached bo by default
- cleanups for fbdev, fb-helpers
- better docs for drm modes and SCALING_FITLER uapi
- ttm: fix dma32 page pool regression
Driver Changes:
- multi-hop regression fixes for amdgpu, radeon, nouveau
- lots of small amdgpu hw enabling fixes (display, pm, ...)
- fixes for imx, mcde, meson, some panels, virtio, qxl, i915, all
fairly minor
- some cleanups for legacy drm/fbdev drivers
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Merge tag 'drm-next-2020-12-18' of git://anongit.freedesktop.org/drm/drm
Pull more drm updates from Daniel Vetter:
"UAPI Changes:
- Only enable char/agp uapi when CONFIG_DRM_LEGACY is set
Cross-subsystem Changes:
- vma_set_file helper to make vma->vm_file changing less brittle,
acked by Andrew
Core Changes:
- dma-buf heaps improvements
- pass full atomic modeset state to driver callbacks
- shmem helpers: cached bo by default
- cleanups for fbdev, fb-helpers
- better docs for drm modes and SCALING_FITLER uapi
- ttm: fix dma32 page pool regression
Driver Changes:
- multi-hop regression fixes for amdgpu, radeon, nouveau
- lots of small amdgpu hw enabling fixes (display, pm, ...)
- fixes for imx, mcde, meson, some panels, virtio, qxl, i915, all
fairly minor
- some cleanups for legacy drm/fbdev drivers"
* tag 'drm-next-2020-12-18' of git://anongit.freedesktop.org/drm/drm: (117 commits)
drm/qxl: don't allocate a dma_address array
drm/nouveau: fix multihop when move doesn't work.
drm/i915/tgl: Fix REVID macros for TGL to fetch correct stepping
drm/i915: Fix mismatch between misplaced vma check and vma insert
drm/i915/perf: also include Gen11 in OATAILPTR workaround
Revert "drm/i915: re-order if/else ladder for hpd_irq_setup"
drm/amdgpu/disply: fix documentation warnings in display manager
drm/amdgpu: print mmhub client name for dimgrey_cavefish
drm/amdgpu: set mode1 reset as default for dimgrey_cavefish
drm/amd/display: Add get_dig_frontend implementation for DCEx
drm/radeon: remove h from printk format specifier
drm/amdgpu: remove h from printk format specifier
drm/amdgpu: Fix spelling mistake "Heterogenous" -> "Heterogeneous"
drm/amdgpu: fix regression in vbios reservation handling on headless
drm/amdgpu/SRIOV: Extend VF reset request wait period
drm/amdkfd: correct amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu log.
drm/amd/display: Adding prototype for dccg21_update_dpp_dto()
drm/amdgpu: print what method we are using for runtime pm
drm/amdgpu: simplify logic in atpx resume handling
drm/amdgpu: no need to call pci_ignore_hotplug for _PR3
...
Improve tracking of early memory allocations when memblock debug is
enabled:
* Add memblock_dbg() to memblock_phys_alloc_range() to get details about
its usage
* Make memblock allocator wrappers actually inline to track their callers
in memblock debug messages
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Merge tag 'memblock-v5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
Pull memblock updates from Mike Rapoport:
"memblock debug enhancements.
Improve tracking of early memory allocations when memblock debug is
enabled:
- Add memblock_dbg() to memblock_phys_alloc_range() to get details
about its usage
- Make memblock allocator wrappers actually inline to track their
callers in memblock debug messages"
* tag 'memblock-v5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
mm: memblock: drop __init from memblock functions to make it inline
mm: memblock: add more debug logs
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Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
"Another series of killing more code than what is being added, again
thanks to Christoph's relentless cleanups and tech debt tackling.
This contains:
- blk-iocost improvements (Baolin Wang)
- part0 iostat fix (Jeffle Xu)
- Disable iopoll for split bios (Jeffle Xu)
- block tracepoint cleanups (Christoph Hellwig)
- Merging of struct block_device and hd_struct (Christoph Hellwig)
- Rework/cleanup of how block device sizes are updated (Christoph
Hellwig)
- Simplification of gendisk lookup and removal of block device
aliasing (Christoph Hellwig)
- Block device ioctl cleanups (Christoph Hellwig)
- Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig)
- Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig)
- sbitmap improvements (Pavel Begunkov)
- Hybrid polling fix (Pavel Begunkov)
- bvec iteration improvements (Pavel Begunkov)
- Zone revalidation fixes (Damien Le Moal)
- blk-throttle limit fix (Yu Kuai)
- Various little fixes"
* tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits)
blk-mq: fix msec comment from micro to milli seconds
blk-mq: update arg in comment of blk_mq_map_queue
blk-mq: add helper allocating tagset->tags
Revert "block: Fix a lockdep complaint triggered by request queue flushing"
nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class
blk-mq: add new API of blk_mq_hctx_set_fq_lock_class
block: disable iopoll for split bio
block: Improve blk_revalidate_disk_zones() checks
sbitmap: simplify wrap check
sbitmap: replace CAS with atomic and
sbitmap: remove swap_lock
sbitmap: optimise sbitmap_deferred_clear()
blk-mq: skip hybrid polling if iopoll doesn't spin
blk-iocost: Factor out the base vrate change into a separate function
blk-iocost: Factor out the active iocgs' state check into a separate function
blk-iocost: Move the usage ratio calculation to the correct place
blk-iocost: Remove unnecessary advance declaration
blk-iocost: Fix some typos in comments
blktrace: fix up a kerneldoc comment
block: remove the request_queue to argument request based tracepoints
...
Pull parisc updates from Helge Deller:
"A change to increase the default maximum stack size on parisc to 100MB
and the ability to further increase the stack hard limit size at
runtime with ulimit for newly started processes.
The other patches fix compile warnings, utilize the Kbuild logic and
cleanups the parisc arch code"
* 'parisc-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: pci-dma: fix warning unused-function
parisc/uapi: Use Kbuild logic to provide <asm/types.h>
parisc: Make user stack size configurable
parisc: Use _TIF_USER_WORK_MASK in entry.S
parisc: Drop loops_per_jiffy from per_cpu struct
Merge __follow_pte_pmd, follow_pte_pmd and follow_pte into a single
follow_pte function and just pass two additional NULL arguments for the
two previous follow_pte callers.
[sfr@canb.auug.org.au: merge fix for "s390/pci: remove races against pte updates"]
Link: https://lkml.kernel.org/r/20201111221254.7f6a3658@canb.auug.org.au
Link: https://lkml.kernel.org/r/20201029101432.47011-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "simplify follow_pte a bit".
This small series drops the not needed follow_pte_pmd exports, and
simplifies the follow_pte family of functions a bit.
This patch (of 2):
follow_pte_pmd() is only used by the DAX code, which can't be modular.
Link: https://lkml.kernel.org/r/20201029101432.47011-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On PowerPC, when dymically removing memory from a system we can see in the
console a lot of messages like this:
[ 186.575389] Offlined Pages 4096
This message is displayed on each LMB (256MB) removed, which means that we
removing 1TB of memory, this message is displayed 4096 times.
Moving it to DEBUG to not flood the console.
Link: https://lkml.kernel.org/r/20201211150157.91399-1-ldufour@linux.ibm.com
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Scott Cheloha <cheloha@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The scenario on which "Free swap = -4kB" happens in my system, which is caused
by several get_swap_pages racing with each other and show_swap_cache_info
happens simutaniously. No need to add a lock on get_swap_page_of_type as we
remove "Presub/PosAdd" here.
ProcessA ProcessB ProcessC
ngoals = 1 ngoals = 1
avail = nr_swap_pages(1) avail = nr_swap_pages(1)
nr_swap_pages(1) -= ngoals
nr_swap_pages(0) -= ngoals
nr_swap_pages = -1
Link: https://lkml.kernel.org/r/1607050340-4535-1-git-send-email-zhaoyang.huang@unisoc.com
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge more updates from Andrew Morton:
"More MM work: a memcg scalability improvememt"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm/lru: revise the comments of lru_lock
mm/lru: introduce relock_page_lruvec()
mm/lru: replace pgdat lru_lock with lruvec lock
mm/swap.c: serialize memcg changes in pagevec_lru_move_fn
mm/compaction: do page isolation first in compaction
mm/lru: introduce TestClearPageLRU()
mm/mlock: remove __munlock_isolate_lru_page()
mm/mlock: remove lru_lock on TestClearPageMlocked
mm/vmscan: remove lruvec reget in move_pages_to_lru
mm/lru: move lock into lru_note_cost
mm/swap.c: fold vm event PGROTATED into pagevec_move_tail_fn
mm/memcg: add debug checking in lock_page_memcg
mm: page_idle_get_page() does not need lru_lock
mm/rmap: stop store reordering issue on page->mapping
mm/vmscan: remove unnecessary lruvec adding
mm/thp: narrow lru locking
mm/thp: simplify lru_add_page_tail()
mm/thp: use head for head page in lru_add_page_tail()
mm/thp: move lru_add_page_tail() to huge_memory.c
Since we changed the pgdat->lru_lock to lruvec->lru_lock, it's time to fix
the incorrect comments in code. Also fixed some zone->lru_lock comment
error from ancient time. etc.
I struggled to understand the comment above move_pages_to_lru() (surely
it never calls page_referenced()), and eventually realized that most of
it had got separated from shrink_active_list(): move that comment back.
Link: https://lkml.kernel.org/r/1604566549-62481-20-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Jann Horn <jannh@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add relock_page_lruvec() to replace repeated same code, no functional
change.
When testing for relock we can avoid the need for RCU locking if we simply
compare the page pgdat and memcg pointers versus those that the lruvec is
holding. By doing this we can avoid the extra pointer walks and accesses
of the memory cgroup.
In addition we can avoid the checks entirely if lruvec is currently NULL.
[alex.shi@linux.alibaba.com: use page_memcg()]
Link: https://lkml.kernel.org/r/66d8e79d-7ec6-bfbc-1c82-bf32db3ae5b7@linux.alibaba.com
Link: https://lkml.kernel.org/r/1604566549-62481-19-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch moves per node lru_lock into lruvec, thus bring a lru_lock for
each of memcg per node. So on a large machine, each of memcg don't have
to suffer from per node pgdat->lru_lock competition. They could go fast
with their self lru_lock.
After move memcg charge before lru inserting, page isolation could
serialize page's memcg, then per memcg lruvec lock is stable and could
replace per node lru lock.
In isolate_migratepages_block(), compact_unlock_should_abort and
lock_page_lruvec_irqsave are open coded to work with compact_control.
Also add a debug func in locking which may give some clues if there are
sth out of hands.
Daniel Jordan's testing show 62% improvement on modified readtwice case on
his 2P * 10 core * 2 HT broadwell box.
https://lore.kernel.org/lkml/20200915165807.kpp7uhiw7l3loofu@ca-dmjordan1.us.oracle.com/
Hugh Dickins helped on the patch polish, thanks!
[alex.shi@linux.alibaba.com: fix comment typo]
Link: https://lkml.kernel.org/r/5b085715-292a-4b43-50b3-d73dc90d1de5@linux.alibaba.com
[alex.shi@linux.alibaba.com: use page_memcg()]
Link: https://lkml.kernel.org/r/5a4c2b72-7ee8-2478-fc0e-85eb83aafec4@linux.alibaba.com
Link: https://lkml.kernel.org/r/1604566549-62481-18-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rong Chen <rong.a.chen@intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins' found a memcg change bug on original version: If we want to
change the pgdat->lru_lock to memcg's lruvec lock, we have to serialize
mem_cgroup_move_account during pagevec_lru_move_fn. The possible bad
scenario would like:
cpu 0 cpu 1
lruvec = mem_cgroup_page_lruvec()
if (!isolate_lru_page())
mem_cgroup_move_account
spin_lock_irqsave(&lruvec->lru_lock <== wrong lock.
So we need TestClearPageLRU to block isolate_lru_page(), that serializes
the memcg change. and then removing the PageLRU check in move_fn callee
as the consequence.
__pagevec_lru_add_fn() is different from the others, because the pages it
deals with are, by definition, not yet on the lru. TestClearPageLRU is
not needed and would not work, so __pagevec_lru_add() goes its own way.
Link: https://lkml.kernel.org/r/1604566549-62481-17-git-send-email-alex.shi@linux.alibaba.com
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, compaction would get the lru_lock and then do page isolation
which works fine with pgdat->lru_lock, since any page isoltion would
compete for the lru_lock. If we want to change to memcg lru_lock, we have
to isolate the page before getting lru_lock, thus isoltion would block
page's memcg change which relay on page isoltion too. Then we could
safely use per memcg lru_lock later.
The new page isolation use previous introduced TestClearPageLRU() + pgdat
lru locking which will be changed to memcg lru lock later.
Hugh Dickins <hughd@google.com> fixed following bugs in this patch's early
version:
Fix lots of crashes under compaction load: isolate_migratepages_block()
must clean up appropriately when rejecting a page, setting PageLRU again
if it had been cleared; and a put_page() after get_page_unless_zero()
cannot safely be done while holding locked_lruvec - it may turn out to be
the final put_page(), which will take an lruvec lock when PageLRU.
And move __isolate_lru_page_prepare back after get_page_unless_zero to
make trylock_page() safe: trylock_page() is not safe to use at this time:
its setting PG_locked can race with the page being freed or allocated
("Bad page"), and can also erase flags being set by one of those "sole
owners" of a freshly allocated page who use non-atomic __SetPageFlag().
Link: https://lkml.kernel.org/r/1604566549-62481-16-git-send-email-alex.shi@linux.alibaba.com
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently lru_lock still guards both lru list and page's lru bit, that's
ok. but if we want to use specific lruvec lock on the page, we need to
pin down the page's lruvec/memcg during locking. Just taking lruvec lock
first may be undermined by the page's memcg charge/migration. To fix this
problem, we will clear the lru bit out of locking and use it as pin down
action to block the page isolation in memcg changing.
So now a standard steps of page isolation is following:
1, get_page(); #pin the page avoid to be free
2, TestClearPageLRU(); #block other isolation like memcg change
3, spin_lock on lru_lock; #serialize lru list access
4, delete page from lru list;
This patch start with the first part: TestClearPageLRU, which combines
PageLRU check and ClearPageLRU into a macro func TestClearPageLRU. This
function will be used as page isolation precondition to prevent other
isolations some where else. Then there are may !PageLRU page on lru list,
need to remove BUG() checking accordingly.
There 2 rules for lru bit now:
1, the lru bit still indicate if a page on lru list, just in some
temporary moment(isolating), the page may have no lru bit when
it's on lru list. but the page still must be on lru list when the
lru bit set.
2, have to remove lru bit before delete it from lru list.
As Andrew Morton mentioned this change would dirty cacheline for a page
which isn't on the LRU. But the loss would be acceptable in Rong Chen
<rong.a.chen@intel.com> report:
https://lore.kernel.org/lkml/20200304090301.GB5972@shao2-debian/
Link: https://lkml.kernel.org/r/1604566549-62481-15-git-send-email-alex.shi@linux.alibaba.com
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__munlock_isolate_lru_page() only has one caller, remove it to clean up
and simplify code.
Link: https://lkml.kernel.org/r/1604566549-62481-14-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the func munlock_vma_page, comments mentained lru_lock needed for
serialization with split_huge_pages. But the page must be PageLocked as
well as pages in split_huge_page series funcs. Thus the PageLocked is
enough to serialize both funcs.
Further more, Hugh Dickins pointed: before splitting in
split_huge_page_to_list, the page was unmap_page() to remove pmd/ptes
which protect the page from munlock. Thus, no needs to guard
__split_huge_page_tail for mlock clean, just keep the lru_lock there for
isolation purpose.
LKP found a preempt issue on __mod_zone_page_state which need change to
mod_zone_page_state. Thanks!
Link: https://lkml.kernel.org/r/1604566549-62481-13-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Isolated page shouldn't be recharged by memcg since the memcg migration
isn't possible at the time. All pages were isolated from the same lruvec
(and isolation inhibits memcg migration). So remove unnecessary
regetting.
Thanks to Alexander Duyck for pointing this out.
Link: https://lkml.kernel.org/r/1604566549-62481-12-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have to move lru_lock into lru_note_cost, since it cycle up on memcg
tree, for future per lruvec lru_lock replace. It's a bit ugly and may
cost a bit more locking, but benefit from multiple memcg locking could
cover the lost.
Link: https://lkml.kernel.org/r/1604566549-62481-11-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fold the PGROTATED event collection into pagevec_move_tail_fn call back
func like other funcs does in pagevec_lru_move_fn. Thus we could save
func call pagevec_move_tail(). Now all usage of pagevec_lru_move_fn are
same and no needs of its 3rd parameter.
It's just simply the calling. No functional change.
[lkp@intel.com: found a build issue in the original patch, thanks]
Link: https://lkml.kernel.org/r/1604566549-62481-10-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a debug checking in lock_page_memcg, then we could get alarm if
anything wrong here.
Link: https://lkml.kernel.org/r/1604566549-62481-9-git-send-email-alex.shi@linux.alibaba.com
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is necessary for page_idle_get_page() to recheck PageLRU() after
get_page_unless_zero(), but holding lru_lock around that serves no
useful purpose, and adds to lru_lock contention: delete it.
See https://lore.kernel.org/lkml/20150504031722.GA2768@blaptop for the
discussion that led to lru_lock there; but __page_set_anon_rmap() now uses
WRITE_ONCE(), and I see no other risk in page_idle_clear_pte_refs() using
rmap_walk() (beyond the risk of racing PageAnon->PageKsm, mostly but not
entirely prevented by page_count() check in ksm.c's write_protect_page():
that risk being shared with page_referenced() and not helped by lru_lock).
Link: https://lkml.kernel.org/r/1604566549-62481-8-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins and Minchan Kim observed a long time issue which discussed
here, but actully the mentioned fix in
https://lore.kernel.org/lkml/20150504031722.GA2768@blaptop/
was missed.
The store reordering may cause problem in the scenario:
CPU 0 CPU1
do_anonymous_page
page_add_new_anon_rmap()
page->mapping = anon_vma + PAGE_MAPPING_ANON
lru_cache_add_inactive_or_unevictable()
spin_lock(lruvec->lock)
SetPageLRU()
spin_unlock(lruvec->lock)
/* idletacking judged it as LRU
* page so pass the page in
* page_idle_clear_pte_refs
*/
page_idle_clear_pte_refs
rmap_walk
if PageAnon(page)
Johannes give detailed examples how the store reordering could cause
trouble: "The concern is the SetPageLRU may get reorder before
'page->mapping' setting, That would make CPU 1 will observe at
page->mapping after observing PageLRU set on the page.
1. anon_vma + PAGE_MAPPING_ANON
That's the in-order scenario and is fine.
2. NULL
That's possible if the page->mapping store gets reordered to occur
after SetPageLRU. That's fine too because we check for it.
3. anon_vma without the PAGE_MAPPING_ANON bit
That would be a problem and could lead to all kinds of undesirable
behavior including crashes and data corruption.
Is it possible? AFAICT the compiler is allowed to tear the store to
page->mapping and I don't see anything that would prevent it.
That said, I also don't see how the reader testing PageLRU under the
lru_lock would prevent that in the first place. AFAICT we need that
WRITE_ONCE() around the page->mapping assignment."
[alex.shi@linux.alibaba.com: updated for comments change from Johannes]
Link: https://lkml.kernel.org/r/e66ef2e5-c74c-6498-e8b3-56c37b9d2d15@linux.alibaba.com
Link: https://lkml.kernel.org/r/1604566549-62481-7-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We don't have to add a freeable page into lru and then remove from it.
This change saves a couple of actions and makes the moving more clear.
The SetPageLRU needs to be kept before put_page_testzero for list
integrity, otherwise:
#0 move_pages_to_lru #1 release_pages
if !put_page_testzero
if (put_page_testzero())
!PageLRU //skip lru_lock
SetPageLRU()
list_add(&page->lru,)
list_add(&page->lru,)
[akpm@linux-foundation.org: coding style fixes]
Link: https://lkml.kernel.org/r/1604566549-62481-6-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lru_lock and page cache xa_lock have no obvious reason to be taken one
way round or the other: until now, lru_lock has been taken before page
cache xa_lock, when splitting a THP; but nothing else takes them
together. Reverse that ordering: let's narrow the lru locking - but
leave local_irq_disable to block interrupts throughout, like before.
Hugh Dickins point: split_huge_page_to_list() was already silly, to be
using the _irqsave variant: it's just been taking sleeping locks, so
would already be broken if entered with interrupts enabled. So we can
save passing flags argument down to __split_huge_page().
Why change the lock ordering here? That was hard to decide. One reason:
when this series reaches per-memcg lru locking, it relies on the THP's
memcg to be stable when taking the lru_lock: that is now done after the
THP's refcount has been frozen, which ensures page memcg cannot change.
Another reason: previously, lock_page_memcg()'s move_lock was presumed
to nest inside lru_lock; but now lru_lock must nest inside (page cache
lock inside) move_lock, so it becomes possible to use lock_page_memcg()
to stabilize page memcg before taking its lru_lock. That is not the
mechanism used in this series, but it is an option we want to keep open.
[hughd@google.com: rewrite commit log]
Link: https://lkml.kernel.org/r/1604566549-62481-5-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simplify lru_add_page_tail(), there are actually only two cases
possible: split_huge_page_to_list(), with list supplied and head
isolated from lru by its caller; or split_huge_page(), with NULL list
and head on lru - because when head is racily isolated from lru, the
isolator's reference will stop the split from getting any further than
its page_ref_freeze().
So decide between the two cases by "list", but add VM_WARN_ON()s to
verify that they match our lru expectations.
[Hugh Dickins: rewrite commit log]
Link: https://lkml.kernel.org/r/1604566549-62481-4-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since the first parameter is only used by head page, it's better to make
it explicit.
Link: https://lkml.kernel.org/r/1604566549-62481-3-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "per memcg lru lock", v21.
This patchset includes 3 parts:
1) some code cleanup and minimum optimization as preparation
2) use TestCleanPageLRU as page isolation's precondition
3) replace per node lru_lock with per memcg per node lru_lock
Current lru_lock is one for each of node, pgdat->lru_lock, that guard
for lru lists, but now we had moved the lru lists into memcg for long
time. Still using per node lru_lock is clearly unscalable, pages on
each of memcgs have to compete each others for a whole lru_lock. This
patchset try to use per lruvec/memcg lru_lock to repleace per node lru
lock to guard lru lists, make it scalable for memcgs and get performance
gain.
Currently lru_lock still guards both lru list and page's lru bit, that's
ok. but if we want to use specific lruvec lock on the page, we need to
pin down the page's lruvec/memcg during locking. Just taking lruvec
lock first may be undermined by the page's memcg charge/migration. To
fix this problem, we could take out the page's lru bit clear and use it
as pin down action to block the memcg changes. That's the reason for
new atomic func TestClearPageLRU. So now isolating a page need both
actions: TestClearPageLRU and hold the lru_lock.
The typical usage of this is isolate_migratepages_block() in
compaction.c we have to take lru bit before lru lock, that serialized
the page isolation in memcg page charge/migration which will change
page's lruvec and new lru_lock in it.
The above solution suggested by Johannes Weiner, and based on his new
memcg charge path, then have this patchset. (Hugh Dickins tested and
contributed much code from compaction fix to general code polish, thanks
a lot!).
Daniel Jordan's testing show 62% improvement on modified readtwice case
on his 2P * 10 core * 2 HT broadwell box on v18, which has no much
different with this v20.
https://lore.kernel.org/lkml/20200915165807.kpp7uhiw7l3loofu@ca-dmjordan1.us.oracle.com/
Thanks to Hugh Dickins and Konstantin Khlebnikov, they both brought this
idea 8 years ago, and others who gave comments as well: Daniel Jordan,
Mel Gorman, Shakeel Butt, Matthew Wilcox, Alexander Duyck etc.
Thanks for Testing support from Intel 0day and Rong Chen, Fengguang Wu,
and Yun Wang. Hugh Dickins also shared his kbuild-swap case.
This patch (of 19):
lru_add_page_tail() is only used in huge_memory.c, defining it in other
file with a CONFIG_TRANSPARENT_HUGEPAGE macro restrict just looks weird.
Let's move it THP. And make it static as Hugh Dickins suggested.
Link: https://lkml.kernel.org/r/1604566549-62481-1-git-send-email-alex.shi@linux.alibaba.com
Link: https://lkml.kernel.org/r/1604566549-62481-2-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Core:
- support "prefer busy polling" NAPI operation mode, where we defer softirq
for some time expecting applications to periodically busy poll
- AF_XDP: improve efficiency by more batching and hindering
the adjacency cache prefetcher
- af_packet: make packet_fanout.arr size configurable up to 64K
- tcp: optimize TCP zero copy receive in presence of partial or unaligned
reads making zero copy a performance win for much smaller messages
- XDP: add bulk APIs for returning / freeing frames
- sched: support fragmenting IP packets as they come out of conntrack
- net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs
BPF:
- BPF switch from crude rlimit-based to memcg-based memory accounting
- BPF type format information for kernel modules and related tracing
enhancements
- BPF implement task local storage for BPF LSM
- allow the FENTRY/FEXIT/RAW_TP tracing programs to use bpf_sk_storage
Protocols:
- mptcp: improve multiple xmit streams support, memory accounting and
many smaller improvements
- TLS: support CHACHA20-POLY1305 cipher
- seg6: add support for SRv6 End.DT4/DT6 behavior
- sctp: Implement RFC 6951: UDP Encapsulation of SCTP
- ppp_generic: add ability to bridge channels directly
- bridge: Connectivity Fault Management (CFM) support as is defined in
IEEE 802.1Q section 12.14.
Drivers:
- mlx5: make use of the new auxiliary bus to organize the driver internals
- mlx5: more accurate port TX timestamping support
- mlxsw:
- improve the efficiency of offloaded next hop updates by using
the new nexthop object API
- support blackhole nexthops
- support IEEE 802.1ad (Q-in-Q) bridging
- rtw88: major bluetooth co-existance improvements
- iwlwifi: support new 6 GHz frequency band
- ath11k: Fast Initial Link Setup (FILS)
- mt7915: dual band concurrent (DBDC) support
- net: ipa: add basic support for IPA v4.5
Refactor:
- a few pieces of in_interrupt() cleanup work from Sebastian Andrzej Siewior
- phy: add support for shared interrupts; get rid of multiple driver
APIs and have the drivers write a full IRQ handler, slight growth
of driver code should be compensated by the simpler API which
also allows shared IRQs
- add common code for handling netdev per-cpu counters
- move TX packet re-allocation from Ethernet switch tag drivers to
a central place
- improve efficiency and rename nla_strlcpy
- number of W=1 warning cleanups as we now catch those in a patchwork
build bot
Old code removal:
- wan: delete the DLCI / SDLA drivers
- wimax: move to staging
- wifi: remove old WDS wifi bridging support
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core:
- support "prefer busy polling" NAPI operation mode, where we defer
softirq for some time expecting applications to periodically busy
poll
- AF_XDP: improve efficiency by more batching and hindering the
adjacency cache prefetcher
- af_packet: make packet_fanout.arr size configurable up to 64K
- tcp: optimize TCP zero copy receive in presence of partial or
unaligned reads making zero copy a performance win for much smaller
messages
- XDP: add bulk APIs for returning / freeing frames
- sched: support fragmenting IP packets as they come out of conntrack
- net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs
BPF:
- BPF switch from crude rlimit-based to memcg-based memory accounting
- BPF type format information for kernel modules and related tracing
enhancements
- BPF implement task local storage for BPF LSM
- allow the FENTRY/FEXIT/RAW_TP tracing programs to use
bpf_sk_storage
Protocols:
- mptcp: improve multiple xmit streams support, memory accounting and
many smaller improvements
- TLS: support CHACHA20-POLY1305 cipher
- seg6: add support for SRv6 End.DT4/DT6 behavior
- sctp: Implement RFC 6951: UDP Encapsulation of SCTP
- ppp_generic: add ability to bridge channels directly
- bridge: Connectivity Fault Management (CFM) support as is defined
in IEEE 802.1Q section 12.14.
Drivers:
- mlx5: make use of the new auxiliary bus to organize the driver
internals
- mlx5: more accurate port TX timestamping support
- mlxsw:
- improve the efficiency of offloaded next hop updates by using
the new nexthop object API
- support blackhole nexthops
- support IEEE 802.1ad (Q-in-Q) bridging
- rtw88: major bluetooth co-existance improvements
- iwlwifi: support new 6 GHz frequency band
- ath11k: Fast Initial Link Setup (FILS)
- mt7915: dual band concurrent (DBDC) support
- net: ipa: add basic support for IPA v4.5
Refactor:
- a few pieces of in_interrupt() cleanup work from Sebastian Andrzej
Siewior
- phy: add support for shared interrupts; get rid of multiple driver
APIs and have the drivers write a full IRQ handler, slight growth
of driver code should be compensated by the simpler API which also
allows shared IRQs
- add common code for handling netdev per-cpu counters
- move TX packet re-allocation from Ethernet switch tag drivers to a
central place
- improve efficiency and rename nla_strlcpy
- number of W=1 warning cleanups as we now catch those in a patchwork
build bot
Old code removal:
- wan: delete the DLCI / SDLA drivers
- wimax: move to staging
- wifi: remove old WDS wifi bridging support"
* tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1922 commits)
net: hns3: fix expression that is currently always true
net: fix proc_fs init handling in af_packet and tls
nfc: pn533: convert comma to semicolon
af_vsock: Assign the vsock transport considering the vsock address flags
af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path
vsock_addr: Check for supported flag values
vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag
vm_sockets: Add flags field in the vsock address data structure
net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled
tcp: Add logic to check for SYN w/ data in tcp_simple_retransmit
net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context
nfc: s3fwrn5: Release the nfc firmware
net: vxget: clean up sparse warnings
mlxsw: spectrum_router: Use eXtended mezzanine to offload IPv4 router
mlxsw: spectrum: Set KVH XLT cache mode for Spectrum2/3
mlxsw: spectrum_router_xm: Introduce basic XM cache flushing
mlxsw: reg: Add Router LPM Cache Enable Register
mlxsw: reg: Add Router LPM Cache ML Delete Register
mlxsw: spectrum_router_xm: Implement L-value tracking for M-index
mlxsw: reg: Add XM Router M Table Register
...
Merge misc updates from Andrew Morton:
- a few random little subsystems
- almost all of the MM patches which are staged ahead of linux-next
material. I'll trickle to post-linux-next work in as the dependents
get merged up.
Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
mm: cleanup kstrto*() usage
mm: fix fall-through warnings for Clang
mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
mm:backing-dev: use sysfs_emit in macro defining functions
mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
mm: use sysfs_emit for struct kobject * uses
mm: fix kernel-doc markups
zram: break the strict dependency from lzo
zram: add stat to gather incompressible pages since zram set up
zram: support page writeback
mm/process_vm_access: remove redundant initialization of iov_r
mm/zsmalloc.c: rework the list_add code in insert_zspage()
mm/zswap: move to use crypto_acomp API for hardware acceleration
mm/zswap: fix passing zero to 'PTR_ERR' warning
mm/zswap: make struct kernel_param_ops definitions const
userfaultfd/selftests: hint the test runner on required privilege
userfaultfd/selftests: fix retval check for userfaultfd_open()
userfaultfd/selftests: always dump something in modes
userfaultfd: selftests: make __{s,u}64 format specifiers portable
...
Range checks can folded into proper conversion function. kstrto*() exist
for all arithmetic types.
Link: https://lkml.kernel.org/r/20201122123759.GC92364@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In preparation to enable -Wimplicit-fallthrough for Clang, fix a couple of
warnings by explicitly adding a break statement instead of just letting
the code fall through to the next, and by adding a fallthrough
pseudo-keyword in places where the code is intended to fall through.
Link: https://github.com/KSPP/linux/issues/115
Link: https://lkml.kernel.org/r/f5756988b8842a3f10008fbc5b0a654f828920a9.1605896059.git.gustavoars@kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert the unbounded uses of sprintf to sysfs_emit.
A few conversions may now not end in a newline if the output buffer is
overflowed.
Link: https://lkml.kernel.org/r/0c90a90f466167f8c37de4b737553cf49c4a277f.1605376435.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Update the function to use sysfs_emit_at while neatening the uses of
sprintf and overwriting the last space char with a newline to avoid
possible output buffer overflow.
Miscellanea:
- in shmem_enabled_show, the removal of the indirected use of fmt
allows __printf verification
Link: https://lkml.kernel.org/r/b612a93825e5ea330cb68d2e8b516e9687a06cc6.1605376435.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The cocci script used in commit bdacbb8d04f ("mm: Use sysfs_emit for
struct kobject * uses") does not convert the name##_show macro because the
macro uses concatenation via ##.
Convert it by hand.
Link: https://lkml.kernel.org/r/45ec6cfc177d743f9c0ebaf35e43969dce43af42.1605376435.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert the only use of sprintf with struct kobject * that the cocci
script could not convert.
Miscellanea:
- Neaten the uses of a constant string with sysfs_emit to use a const
char * to reduce overall object size
Link: https://lkml.kernel.org/r/7df6be66bbd68e1a0bca9d35aca1341dbf94d2a7.1605376435.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: Convert sysfs sprintf family to sysfs_emit", v2.
Use the new sysfs_emit family and not the sprintf family.
This patch (of 5):
Use the sysfs_emit function instead of the sprintf family.
Done with cocci script as in commit 3c6bff3cf9 ("RDMA: Convert sysfs
kobject * show functions to use sysfs_emit()")
Link: https://lkml.kernel.org/r/cover.1605376435.git.joe@perches.com
Link: https://lkml.kernel.org/r/9c249215bad6df616ba0410ad980042694970c1b.1605376435.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kernel-doc markups should use this format:
identifier - description
Fix some issues on mm files:
1) The definition for get_user_pages_locked() doesn't follow it. Also,
it expects a short descrpition at the header, followed by a long one,
after the parameters. Fix it.
2) Kernel-doc requires that a kernel-doc markup to be immediately below
the function prototype, as otherwise it will rename it. So, move
get_pfnblock_flags_mask() description to the right place.
3) Make invalidate_mapping_pagevec() to also follow the expected
kernel-doc format.
While here, fix a few minor English syntax issues, as suggested
by Matthew:
will used -> will be used
similar with -> similar to
Link: https://lkml.kernel.org/r/80e85dddc92d333bc2159ee8a2294921612e8745.1605521731.git.mchehab+huawei@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Suggested-by: Mattew Wilcox <willy@infradead.org> [English fixes]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The pointer iov_r is being initialized with a value that is never read and
it is being updated later with a new value. The initialization is
redundant and can be removed.
Link: https://lkml.kernel.org/r/20201102120614.694917-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rework the list_add code to make it more readable and simple.
Link: https://lkml.kernel.org/r/20201015130107.65195-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now, all new ZIP drivers are adapted to crypto_acomp APIs rather
than legacy crypto_comp APIs. Tradiontal ZIP drivers like lz4,lzo etc
have been also wrapped into acomp via scomp backend. But zswap.c is still
using the old APIs. That means zswap won't be able to work on any new ZIP
drivers in kernel.
This patch moves to use cryto_acomp APIs to fix the disconnected bridge
between new ZIP drivers and zswap. It is probably the first real user to
use acomp but perhaps not a good example to demonstrate how multiple acomp
requests can be executed in parallel in one acomp instance. frontswap is
doing page load and store page by page synchronously. swap_writepage()
depends on the completion of frontswap_store() to decide if it should call
__swap_writepage() to swap to disk.
However this patch creates multiple acomp instances, so multiple threads
running on multiple different cpus can actually do (de)compression
parallelly, leveraging the power of multiple ZIP hardware queues. This is
also consistent with frontswap's page management model.
The old zswap code uses atomic context and avoids the race conditions
while shared resources like zswap_dstmem are accessed. Here since acomp
can sleep, per-cpu mutex is used to replace preemption-disable.
While it is possible to make mm/page_io.c and mm/frontswap.c support async
(de)compression in some way, the entire design requires careful thinking
and performance evaluation. For the first step, the base with fixed
connection between ZIP drivers and zswap should be built.
Link: https://lkml.kernel.org/r/20201107065332.26992-1-song.bao.hua@hisilicon.com
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Acked-by: Vitaly Wool <vitalywool@gmail.com>
Cc: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mahipal Challa <mahipalreddy2006@gmail.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Zhou Wang <wangzhou1@hisilicon.com>
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These should be const, so make it so.
Link: https://lkml.kernel.org/r/1791535ee0b00f4a5c68cc4a8adada06593ad8f1.1601770305.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_PAGE_POISONING_ZERO uses the zero pattern instead of 0xAA. It was
introduced by commit 1414c7f4f7 ("mm/page_poisoning.c: allow for zero
poisoning"), noting that using zeroes retains the benefit of sanitizing
content of freed pages, with the benefit of not having to zero them again
on alloc, and the downside of making some forms of corruption (stray
writes of NULLs) harder to detect than with the 0xAA pattern. Together
with CONFIG_PAGE_POISONING_NO_SANITY it made possible to sanitize the
contents on free without checking it back on alloc.
These days we have the init_on_free() option to achieve sanitization with
zeroes and to save clearing on alloc (and without checking on alloc).
Arguably if someone does choose to check the poison for corruption on
alloc, the savings of not clearing the page are secondary, and it makes
sense to always use the 0xAA poison pattern. Thus, remove the
CONFIG_PAGE_POISONING_ZERO option for being redundant.
Link: https://lkml.kernel.org/r/20201113104033.22907-6-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_PAGE_POISONING_NO_SANITY skips the check on page alloc whether the
poison pattern was corrupted, suggesting a use-after-free. The motivation
to introduce it in commit 8823b1dbc0 ("mm/page_poison.c: enable
PAGE_POISONING as a separate option") was to simply sanitize freed pages,
optimally together with CONFIG_PAGE_POISONING_ZERO.
These days we have an init_on_free=1 boot option, which makes this use
case of page poisoning redundant. For sanitizing, writing zeroes is
sufficient, there is pretty much no benefit from writing the 0xAA poison
pattern to freed pages, without checking it back on alloc. Thus, remove
this option and suggest init_on_free instead in the main config's help.
Link: https://lkml.kernel.org/r/20201113104033.22907-5-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Page poisoning used to be incompatible with hibernation, as the state of
poisoned pages was lost after resume, thus enabling CONFIG_HIBERNATION
forces CONFIG_PAGE_POISONING_NO_SANITY. For the same reason, the
poisoning with zeroes variant CONFIG_PAGE_POISONING_ZERO used to disable
hibernation. The latter restriction was removed by commit 1ad1410f63
("PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO") and
similarly for init_on_free by commit 18451f9f9e ("PM: hibernate: fix
crashes with init_on_free=1") by making sure free pages are cleared after
resume.
We can use the same mechanism to instead poison free pages with
PAGE_POISON after resume. This covers both zero and 0xAA patterns. Thus
we can remove the Kconfig restriction that disables page poison sanity
checking when hibernation is enabled.
Link: https://lkml.kernel.org/r/20201113104033.22907-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [hibernation]
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 11c9c7edae ("mm/page_poison.c: replace bool variable with static
key") changed page_poisoning_enabled() to a static key check. However,
the function is not inlined, so each check still involves a function call
with overhead not eliminated when page poisoning is disabled.
Analogically to how debug_pagealloc is handled, this patch converts
page_poisoning_enabled() back to boolean check, and introduces
page_poisoning_enabled_static() for fast paths. Both functions are
inlined.
The function kernel_poison_pages() is also called unconditionally and does
the static key check inside. Remove it from there and put it to callers.
Also split it to two functions kernel_poison_pages() and
kernel_unpoison_pages() instead of the confusing bool parameter.
Also optimize the check that enables page poisoning instead of
debug_pagealloc for architectures without proper debug_pagealloc support.
Move the check to init_mem_debugging_and_hardening() to enable a single
static key instead of having two static branches in
page_poisoning_enabled_static().
Link: https://lkml.kernel.org/r/20201113104033.22907-3-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "cleanup page poisoning", v3.
I have identified a number of issues and opportunities for cleanup with
CONFIG_PAGE_POISON and friends:
- interaction with init_on_alloc and init_on_free parameters depends on
the order of parameters (Patch 1)
- the boot time enabling uses static key, but inefficienty (Patch 2)
- sanity checking is incompatible with hibernation (Patch 3)
- CONFIG_PAGE_POISONING_NO_SANITY can be removed now that we have
init_on_free (Patch 4)
- CONFIG_PAGE_POISONING_ZERO can be most likely removed now that we
have init_on_free (Patch 5)
This patch (of 5):
Enabling page_poison=1 together with init_on_alloc=1 or init_on_free=1
produces a warning in dmesg that page_poison takes precedence. However,
as these warnings are printed in early_param handlers for
init_on_alloc/free, they are not printed if page_poison is enabled later
on the command line (handlers are called in the order of their
parameters), or when init_on_alloc/free is always enabled by the
respective config option - before the page_poison early param handler is
called, it is not considered to be enabled. This is inconsistent.
We can remove the dependency on order by making the init_on_* parameters
only set a boolean variable, and postponing the evaluation after all early
params have been processed. Introduce a new
init_mem_debugging_and_hardening() function for that, and move the related
debug_pagealloc processing there as well.
As a result init_mem_debugging_and_hardening() knows always accurately if
init_on_* and/or page_poison options were enabled. Thus we can also
optimize want_init_on_alloc() and want_init_on_free(). We don't need to
check page_poisoning_enabled() there, we can instead not enable the
init_on_* static keys at all, if page poisoning is enabled. This results
in a simpler and more effective code.
Link: https://lkml.kernel.org/r/20201113104033.22907-1-vbabka@suse.cz
Link: https://lkml.kernel.org/r/20201113104033.22907-2-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Laura Abbott <labbott@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is required to print 'count' of pages, along with the pages, passed to
cma_release to debug the cases of mismatched count value passed between
cma_alloc() and cma_release() from a code path.
As an example, consider the below scenario:
1) CMA pool size is 4MB and
2) User doing the erroneous step of allocating 2 pages but freeing 1
page in a loop from this CMA pool. The step 2 causes cma_alloc() to
return NULL at one point of time because of -ENOMEM condition.
And the current pr_debug logs is not giving the info about these types of
allocation patterns because of count value not being printed in
cma_release().
We are printing the count value in the trace logs, just extend the same to
pr_debug logs too.
[akpm@linux-foundation.org: fix printk warning]
Link: https://lkml.kernel.org/r/1606318341-29521-1-git-send-email-charante@codeaurora.org
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Reviewed-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The cma_mutex which protects alloc_contig_range() was first appeared in
commit 7ee793a62f ("cma: Remove potential deadlock situation"), at that
time, there is no guarantee the behavior of concurrency inside
alloc_contig_range().
After commit 2c7452a075 ("mm/page_isolation.c: make
start_isolate_page_range() fail if already isolated")
> However, two subsystems (CMA and gigantic
> huge pages for example) could attempt operations on the same range. If
> this happens, one thread may 'undo' the work another thread is doing.
> This can result in pageblocks being incorrectly left marked as
> MIGRATE_ISOLATE and therefore not available for page allocation.
The concurrency inside alloc_contig_range() was clarified.
Now we can find that hugepage and virtio call alloc_contig_range() without
any lock, thus cma_mutex is "redundant" in cma_alloc() now.
Link: https://lkml.kernel.org/r/20201020102241.3729-1-lecopzer.chen@mediatek.com
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
"dst" parameter to migrate_vma_insert_page() is not used anymore.
Link: https://lkml.kernel.org/r/CANubcdUwCAMuUyamG2dkWP=cqSR9MAS=tHLDc95kQkqU-rEnAg@mail.gmail.com
Signed-off-by: Stephen Zhang <starzhangzsd@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the current implementation unmap_and_move() would return -ENOMEM if THP
migration is unsupported, then the THP will be split. If split is failed
just exit without trying to migrate other pages. It doesn't make too much
sense since there may be enough free memory to migrate other pages and
there may be a lot base pages on the list.
Return -ENOSYS to make consistent with hugetlb. And if THP split is
failed just skip and try other pages on the list.
Just skip the whole list and exit when free memory is really low.
Link: https://lkml.kernel.org/r/20201113205359.556831-6-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The migrate_prep{_local} never fails, so it is pointless to have return
value and check the return value.
Link: https://lkml.kernel.org/r/20201113205359.556831-5-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The NUMA balancing skip shared exec base page. Since
CONFIG_READ_ONLY_THP_FOR_FS was introduced, there are probably shared exec
THP, so skip such THPs for NUMA balancing as well.
And Willy's regular filesystem THP support patches could create shared
exec THP wven without that config.
In addition, the page_is_file_lru() is used to tell if the page is file
cache or not, but it filters out shmem page. It sounds like a typical
usecase by putting executables in shmem to achieve performance gain via
using shmem-THP, so it sounds worth skipping migration for such case too.
Link: https://lkml.kernel.org/r/20201113205359.556831-4-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When unmap_and_move{_huge_page}() returns !-EAGAIN and
!MIGRATEPAGE_SUCCESS, the page would be put back to LRU or proper list if
it is non-LRU movable page. But, the callers always call
putback_movable_pages() to put the failed pages back later on, so it seems
not very efficient to put every single page back immediately, and the code
looks convoluted.
Put the failed page on a separate list, then splice the list to migrate
list when all pages are tried. It is the caller's responsibility to call
putback_movable_pages() to handle failures. This also makes the code
simpler and more readable.
After the change the rules are:
* Success: non hugetlb page will be freed, hugetlb page will be put
back
* -EAGAIN: stay on the from list
* -ENOMEM: stay on the from list
* Other errno: put on ret_pages list then splice to from list
The from list would be empty iff all pages are migrated successfully, it
was not so before. This has no impact to current existing callsites.
Link: https://lkml.kernel.org/r/20201113205359.556831-3-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: misc migrate cleanup and improvement", v3.
This patch (of 5):
The commit 9f4e41f471 ("mm: refactor truncate_complete_page()")
refactored truncate_complete_page(), and it is not existed anymore,
correct the comment in vmscan and migrate to avoid confusion.
Link: https://lkml.kernel.org/r/20201113205359.556831-1-shy828301@gmail.com
Link: https://lkml.kernel.org/r/20201113205359.556831-2-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We can only kmap() one subpage of a THP at a time, so loop over all
relevant subpages, skipping ones which don't need to be zeroed. This is
too large to inline when THPs are enabled and we actually need highmem, so
put it in highmem.c.
[willy@infradead.org: start1 was allowed to be less than start2]
Link: https://lkml.kernel.org/r/20201124041507.28996-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When migrating a zero page or pte_none() anonymous page to device private
memory, migrate_vma_setup() will initialize the src[] array with a NULL
PFN. This lets the device driver allocate device private memory and clear
it instead of DMAing a page of zeros over the device bus.
Since the source page didn't exist at the time, no struct page was locked
nor a migration PTE inserted into the CPU page tables. The actual PTE
insertion happens in migrate_vma_pages() when it tries to insert the
device private struct page PTE into the CPU page tables.
migrate_vma_pages() has to call the mmu notifiers again since another
device could fault on the same page before the page table locks are
acquired.
Allow device drivers to optimize the invalidation similar to
migrate_vma_setup() by calling mmu_notifier_range_init() which sets struct
mmu_notifier_range event type to MMU_NOTIFY_MIGRATE and the
migrate_pgmap_owner field.
Link: https://lkml.kernel.org/r/20201021191335.10916-1-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The word in the comment is misspelled, it should be "include".
Link: https://lkml.kernel.org/r/20201024114144.GA20552@lilong
Signed-off-by: Long Li <lonuxli.64@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the comment of is_dump_unreclaim_slabs(), it just check whether
nr_unreclaimable slabs amount is greater than user memory, and explain why
we dump unreclaim slabs.
Rename it to should_dump_unreclaim_slab() maybe better.
Link: https://lkml.kernel.org/r/20201030182704.GA53949@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
defer_compaction() and compaction_deferred() and compaction_restarting()
in mm/compaction.c won't be used in other files, so make them static, and
remove the declaration in the header file.
Take the chance to fix a typo.
Link: https://lkml.kernel.org/r/20201123170801.GA9625@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Nitin Gupta <nigupta@nvidia.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 837d026d56 ("mm/compaction: more trace to understand
when/why compaction start/finish"), the comment place is not suitable.
So move compaction_suitable's comment to right place.
Link: https://lkml.kernel.org/r/20201116144121.GA385717@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are two 'start_pfn' declared in compact_zone() which have different
meanings. Rename the second one to 'iteration_start_pfn' to prevent
confusion.
Also, remove an useless semicolon.
Link: https://lkml.kernel.org/r/20201019115044.1571-1-yanfei.xu@windriver.com
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace get_cpu_ptr() with migrate_disable()+this_cpu_ptr() so RT can take
spinlocks that become sleeping locks.
Signed-off-by Mike Galbraith <efault@gmx.de>
Link: https://lkml.kernel.org/r/20201209145151.18994-3-vitaly.wool@konsulko.com
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use temporary slots in reclaim function to avoid possible race when
freeing those.
While at it, make sure we check CLAIMED flag under page lock in the
reclaim function to make sure we are not racing with z3fold_alloc().
Link: https://lkml.kernel.org/r/20201209145151.18994-4-vitaly.wool@konsulko.com
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: <stable@vger.kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "z3fold: stability / rt fixes".
Address z3fold stability issues under stress load, primarily in the
reclaim and free aspects. Besides, it fixes the locking problems that
were only seen in real-time kernel configuration.
This patch (of 3):
There used to be two places in the code where slots could be freed, namely
when freeing the last allocated handle from the slots and when releasing
the z3fold header these slots aree linked to. The logic to decide on
whether to free certain slots was complicated and error prone in both
functions and it led to failures in RT case.
To fix that, make free_handle() the single point of freeing slots.
Link: https://lkml.kernel.org/r/20201209145151.18994-1-vitaly.wool@konsulko.com
Link: https://lkml.kernel.org/r/20201209145151.18994-2-vitaly.wool@konsulko.com
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Tested-by: Mike Galbraith <efault@gmx.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A max order page has no buddy page and never merges to another order. So
isolating and then freeing it is pointless.
Link: https://lkml.kernel.org/r/20201202122114.75316-1-songmuchun@bytedance.com
Fixes: 3c605096d3 ("mm/page_alloc: restrict max order of merging on isolated pageblock")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No point in having the filename inside the file.
Link: https://lkml.kernel.org/r/20201115141541.3878-1-hymmsx.yu@gmail.com
Signed-off-by: logic.yu <hymmsx.yu@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The refactoring to kswapd() in commit e716f2eb24 ("mm, vmscan: prevent
kswapd sleeping prematurely due to mismatched classzone_idx") turned an
assignment to reclaim_order into a dead store, as in all further paths,
reclaim_order will be assigned again before it is used.
make clang-analyzer on x86_64 tinyconfig caught my attention with:
mm/vmscan.c: warning: Although the value stored to 'reclaim_order' is used in the enclosing expression, the value is never actually read from 'reclaim_order' [clang-analyzer-deadcode.DeadStores]
Compilers will detect this unneeded assignment and optimize this anyway.
So, the resulting binary is identical before and after this change.
Simplify the code and remove unneeded assignment to make clang-analyzer
happy.
No functional change. No change in binary code.
Link: https://lkml.kernel.org/r/20201004125827.17679-1-lukas.bulwahn@gmail.com
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On 2-node NUMA hosts we see bursts of kswapd reclaim and subsequent
pressure spikes and stalls from cache refaults while there is plenty of
free memory in the system.
Usually, kswapd is woken up when all eligible nodes in an allocation are
full. But the code related to watermark boosting can wake kswapd on one
full node while the other one is mostly empty. This may be justified to
fight fragmentation, but is currently unconditionally done whether
watermark boosting is occurring or not.
In our case, many of our workloads' throughput scales with available
memory, and pure utilization is a more tangible concern than trends
around longer-term fragmentation. As a result we generally disable
watermark boosting.
Wake kswapd only woken when watermark boosting is requested.
Link: https://lkml.kernel.org/r/20201020175833.397286-1-hannes@cmpxchg.org
Fixes: 1c30844d2d ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hugetlb_add_hstate initializes nr_huge_pages and free_huge_pages to 0, but
since hstates[] is a global variable, all its fields are defined to 0
already.
Link: https://lkml.kernel.org/r/20201119112141.6452-1-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On 64-bit machine, delta variable in hugetlb_acct_memory() may be larger
than 0xffffffff, but gather_surplus_pages() can only use the low 32-bit
value now. So we need to fix type of delta parameter and related local
variables in gather_surplus_pages().
Link: https://lkml.kernel.org/r/1605793733-3573-1-git-send-email-liu.xiang@zlingsmart.com
Reported-by: Ma Chenggong <ma.chenggong@zlingsmart.com>
Signed-off-by: Liu Xiang <liu.xiang@zlingsmart.com>
Signed-off-by: Pan Jiagen <pan.jiagen@zlingsmart.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Liu Xiang <liuxiang_1999@126.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add missed parameter explanation for some kernel-doc warnings:
mm/khugepaged.c:102: warning: Function parameter or member 'nr_pte_mapped_thp' not described in 'mm_slot'
mm/khugepaged.c:102: warning: Function parameter or member 'pte_mapped_thp' not described in 'mm_slot'
mm/khugepaged.c:1424: warning: Function parameter or member 'mm' not described in 'collapse_pte_mapped_thp'
mm/khugepaged.c:1424: warning: Function parameter or member 'addr' not described in 'collapse_pte_mapped_thp'
mm/khugepaged.c:1626: warning: Function parameter or member 'mm' not described in 'collapse_file'
mm/khugepaged.c:1626: warning: Function parameter or member 'file' not described in 'collapse_file'
mm/khugepaged.c:1626: warning: Function parameter or member 'start' not described in 'collapse_file'
mm/khugepaged.c:1626: warning: Function parameter or member 'hpage' not described in 'collapse_file'
mm/khugepaged.c:1626: warning: Function parameter or member 'node' not described in 'collapse_file'
Link: https://lkml.kernel.org/r/1605597325-25284-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We test the page reference count is zero or not here, it can be a bug here
if page refercence count is not zero. So we can just use
put_page_testzero() instead of page_count().
Link: https://lkml.kernel.org/r/20201007170949.GA6416@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, we return -EIO when we fail to migrate the page.
Migrations' failures are rather transient as they can happen due to
several reasons, e.g: high page refcount bump, mapping->migrate_page
failing etc. All meaning that at that time the page could not be
migrated, but that has nothing to do with an EIO error.
Let us return -EBUSY instead, as we do in case we failed to isolate the
page.
While are it, let us remove the "ret" print as its value does not change.
Link: https://lkml.kernel.org/r/20201209092818.30417-1-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
madvise_inject_error() uses get_user_pages_fast to translate the address
we specified to a page. After [1], we drop the extra reference count for
memory_failure() path. That commit says that memory_failure wanted to
keep the pin in order to take the page out of circulation.
The truth is that we need to keep the page pinned, otherwise the page
might be re-used after the put_page() and we can end up messing with
someone else's memory.
E.g:
CPU0
process X CPU1
madvise_inject_error
get_user_pages
put_page
page gets reclaimed
process Y allocates the page
memory_failure
// We mess with process Y memory
madvise() is meant to operate on a self address space, so messing with
pages that do not belong to us seems the wrong thing to do.
To avoid that, let us keep the page pinned for memory_failure as well.
Pages for DAX mappings will release this extra refcount in
memory_failure_dev_pagemap.
[1] ("23e7b5c2e271: mm, madvise_inject_error:
Let memory_failure() optionally take a page reference")
Link: https://lkml.kernel.org/r/20201207094818.8518-1-osalvador@suse.de
Fixes: 23e7b5c2e2 ("mm, madvise_inject_error: Let memory_failure() optionally take a page reference")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
get_hwpoison_page already drains pcplists, previously disabling them when
trying to grab a refcount. We do not need shake_page to take care of it
anymore.
Link: https://lkml.kernel.org/r/20201204102558.31607-4-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Qian Cai <qcai@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, we have a sort of retry mechanism to make sure pages in
pcp-lists are spilled to the buddy system, so we can handle those.
We can save us this extra checks with the new disable-pcplist mechanism
that is available with [1].
zone_pcplist_disable makes sure to 1) disable pcplists, so any page that
is freed up from that point onwards will end up in the buddy system and 2)
drain pcplists, so those pages that already in pcplists are spilled to
buddy.
With that, we can make a common entry point for grabbing a refcount from
both soft_offline and memory_failure paths that is guarded by
zone_pcplist_disable/zone_pcplist_enable.
[1] https://patchwork.kernel.org/project/linux-mm/cover/20201111092812.11329-1-vbabka@suse.cz/
Link: https://lkml.kernel.org/r/20201204102558.31607-3-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Qian Cai <qcai@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "HWPoison: Refactor get page interface", v2.
This patch (of 3):
When we want to grab a refcount via get_any_page, we call __get_any_page
that calls get_hwpoison_page to get the actual refcount.
get_any_page() is only there because we have a sort of retry mechanism in
case the page we met is unknown to us or if we raced with an allocation.
Also __get_any_page() prints some messages about the page type in case the
page was a free page or the page type was unknown, but if anything, we
only need to print a message in case the pagetype was unknown, as that is
reporting an error down the chain.
Let us merge get_any_page() and __get_any_page(), and let the message be
printed in soft_offline_page. While we are it, we can also remove the
'pfn' parameter as it is no longer used.
Link: https://lkml.kernel.org/r/20201204102558.31607-1-osalvador@suse.de
Link: https://lkml.kernel.org/r/20201204102558.31607-2-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Acked-by: Vlastimil Babka <Vbabka@suse.cz>
Cc: Qian Cai <qcai@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memory_failure and soft_offline_path paths now drain pcplists by calling
get_hwpoison_page.
memory_failure flags the page as HWPoison before, so that page cannot
longer go into a pcplist, and soft_offline_page only flags a page as
HWPoison if 1) we took the page off a buddy freelist 2) the page was
in-use and we migrated it 3) was a clean pagecache.
Because of that, a page cannot longer be poisoned and be in a pcplist.
Link: https://lkml.kernel.org/r/20201013144447.6706-5-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The crux of the matter is that historically we left poisoned pages in the
buddy system because we have some checks in place when allocating a page
that are gatekeeper for poisoned pages. Unfortunately, we do have other
users (e.g: compaction [1]) that scan buddy freelists and try to get a
page from there without checking whether the page is HWPoison.
As I stated already, I think it is fundamentally wrong to keep HWPoison
pages within the buddy systems, checks in place or not.
Let us fix this the same way we did for soft_offline [2], taking the page
off the buddy freelist so it is completely unreachable.
Note that this is fairly simple to trigger, as we only need to poison free
buddy pages (madvise MADV_HWPOISON) and then run some sort of memory
stress system.
Just for a matter of reference, I put a dump_page() in compaction_alloc()
to trigger for HWPoison patches:
page:0000000012b2982b refcount:1 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x1d5db
flags: 0xfffffc0800000(hwpoison)
raw: 000fffffc0800000 ffffea00007573c8 ffffc90000857de0 0000000000000000
raw: 0000000000000001 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: compaction_alloc
CPU: 4 PID: 123 Comm: kcompactd0 Tainted: G E 5.9.0-rc2-mm1-1-default+ #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
Call Trace:
dump_stack+0x6d/0x8b
compaction_alloc+0xb2/0xc0
migrate_pages+0x2a6/0x12a0
compact_zone+0x5eb/0x11c0
proactive_compact_node+0x89/0xf0
kcompactd+0x2d0/0x3a0
kthread+0x118/0x130
ret_from_fork+0x22/0x30
After that, if e.g: a process faults in the page, it will get killed
unexpectedly.
Fix it by containing the page immediatelly.
Besides that, two more changes can be noticed:
* MF_DELAYED no longer suits as we are fixing the issue by containing
the page immediately, so it does no longer rely on the allocation-time
checks to stop HWPoison to be handed over.
gain unless it is unpoisoned, so we fixed the situation.
Because of that, let us use MF_RECOVERED from now on.
* The second block that handles PageBuddy pages is no longer needed:
We call shake_page and then check whether the page is Buddy
because shake_page calls drain_all_pages, which sends pcp-pages back to
the buddy freelists, so we could have a chance to handle free pages.
Currently, get_hwpoison_page already calls drain_all_pages, and we call
get_hwpoison_page right before coming here, so we should be on the safe
side.
[1] https://lore.kernel.org/linux-mm/20190826104144.GA7849@linux/T/#u
[2] https://patchwork.kernel.org/cover/11792607/
[osalvador@suse.de: take the poisoned subpage off the buddy frelists]
Link: https://lkml.kernel.org/r/20201013144447.6706-4-osalvador@suse.de
Link: https://lkml.kernel.org/r/20201013144447.6706-3-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "HWpoison: further fixes and cleanups", v5.
This patchset includes some more fixes and a cleanup.
Patch#2 and patch#3 are both fixes for taking a HWpoison page off a buddy
freelist, since having them there has proved to be bad (see [1] and
pathch#2's commit log). Patch#3 does the same for hugetlb pages.
[1] https://lkml.org/lkml/2020/9/22/565
This patch (of 4):
A page with 0-refcount and !PageBuddy could perfectly be a pcppage.
Currently, we bail out with an error if we encounter such a page, meaning
that we do not handle pcppages neither from hard-offline nor from
soft-offline path.
Fix this by draining pcplists whenever we find this kind of page and retry
the check again. It might be that pcplists have been spilled into the
buddy allocator and so we can handle it.
Link: https://lkml.kernel.org/r/20201013144447.6706-1-osalvador@suse.de
Link: https://lkml.kernel.org/r/20201013144447.6706-2-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we free a page whose order is very close to MAX_ORDER and greater
than pageblock_order, it wastes some CPU cycles to increase max_order to
MAX_ORDER one by one and check the pageblock migratetype of that page
repeatedly especially when MAX_ORDER is much larger than pageblock_order.
We also should not be checking migratetype of buddy when "order ==
MAX_ORDER - 1" as the buddy pfn may be invalid, so adjust the condition.
With the new check, we don't need the max_order check anymore, so we
replace it.
Also adjust max_order initialization so that it's lower by one than
previously, which makes the code hopefully more clear.
Link: https://lkml.kernel.org/r/20201204155109.55451-1-songmuchun@bytedance.com
Fixes: d9dddbf556 ("mm/page_alloc: prevent merging between isolated and other pageblocks")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
setup_per_zone_lowmem_reserve() iterates through each zone setting
zone->lowmem_reserve[j] = 0 (where j is the zone's index) then iterates
backwards through all preceding zones, setting
lower_zone->lowmem_reserve[j] = sum(managed pages of higher zones) /
lowmem_reserve_ratio[idx] for each (where idx is the lower zone's index).
If the lower zone has no managed pages or its ratio is 0 then all of its
lowmem_reserve[] entries are effectively zeroed.
As these arrays are only assigned here and all lowmem_reserve[] entries
for index < this zone's index are implicitly assumed to be 0 (as these are
specifically output in show_free_areas() and zoneinfo_show_print() for
example) there is no need to additionally zero index == this zone's index
too. This patch avoids zeroing unnecessarily.
Rather than iterating through zones and setting lowmem_reserve[j] for each
lower zone this patch reverse the process and populates each zone's
lowmem_reserve[] values in ascending order.
This clarifies what is going on especially in the case of zero managed
pages or ratio which is now explicitly shown to clear these values.
Link: https://lkml.kernel.org/r/20201129162758.115907-1-lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the booting phase if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set,
we have following callchain:
start_kernel
...
mm_init
mem_init
memblock_free_all
reset_all_zones_managed_pages
free_low_memory_core_early
...
buffer_init
nr_free_buffer_pages
zone->managed_pages
...
rest_init
kernel_init
kernel_init_freeable
page_alloc_init_late
kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
wait_for_completion(&pgdat_init_all_done_comp);
...
files_maxfiles_init
It's clear that buffer_init depends on zone->managed_pages, but it's reset
in reset_all_zones_managed_pages after that pages are readded into
zone->managed_pages, but when buffer_init runs this process is half done
and most of them will finally be added till deferred_init_memmap done. In
large memory couting of nr_free_buffer_pages drifts too much, also
drifting from kernels to kernels on same hardware.
Fix is simple, it delays buffer_init run till deferred_init_memmap all
done.
But as corrected by this patch, max_buffer_heads becomes very large, the
value is roughly as many as 4 times of totalram_pages, formula:
max_buffer_heads = nrpages * (10%) * (PAGE_SIZE / sizeof(struct
buffer_head));
Say in a 64GB memory box we have 16777216 pages, then max_buffer_heads
turns out to be roughly 67,108,864. In common cases, should a buffer_head
be mapped to one page/block(4KB)? So max_buffer_heads never exceeds
totalram_pages. IMO it's likely to make buffer_heads_over_limit bool
value alwasy false, then make codes 'if (buffer_heads_over_limit)' test in
vmscan unnecessary.
So this patch will change the original behavior related to
buffer_heads_over_limit in vmscan since we used a half done value of
zone->managed_pages before, or should we use a smaller factor(<10%) in
previous formula.
akpm: I think this is OK - the max_buffer_heads code is only needed on
highmem machines, to prevent ZONE_NORMAL from being consumed by large
amounts of buffer_heads attached to highmem pagecache. This problem will
not occur on 64-bit machines, so this feature's non-functionality on such
machines is a feature, not a bug.
Link: https://lkml.kernel.org/r/20201123110500.103523-1-linf@wangsu.com
Signed-off-by: Lin Feng <linf@wangsu.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 6471384af2 ("mm: security: introduce init_on_alloc=1 and
init_on_free=1 boot options") resulted with init_on_alloc=1 in all pages
leaving the buddy via alloc_pages() and friends to be
initialized/cleared/zeroed on allocation.
However, the same logic is currently not applied to alloc_contig_pages():
allocated pages leaving the buddy aren't cleared with init_on_alloc=1 and
init_on_free=0. Let's also properly clear pages on that allocation path.
To achieve that, let's move clearing into post_alloc_hook(). This will
not only affect alloc_contig_pages() allocations but also any pages used
as migration target in compaction code via compaction_alloc().
While this sounds sub-optimal, it's the very same handling as when
allocating migration targets via alloc_migration_target() - pages will get
properly cleared with init_on_free=1. In case we ever want to optimize
migration in that regard, we should tackle all such migration users - if
we believe migration code can be fully trusted.
With this change, we will see double clearing of pages in some cases. One
example are gigantic pages (either allocated via CMA, or allocated
dynamically via alloc_contig_pages()) - which is the right thing to do
(and to be optimized outside of the buddy in the callers) as discussed in:
https://lkml.kernel.org/r/20201019182853.7467-1-gpiccoli@canonical.com
This change implies that with init_on_alloc=1
- All CMA allocations will be cleared
- Gigantic pages allocated via alloc_contig_pages() will be cleared
- virtio-mem memory to be unplugged will be cleared. While this is
suboptimal, it's similar to memory balloon drivers handling, where
all pages to be inflated will get cleared as well.
- Pages isolated for compaction will be cleared
Link: https://lkml.kernel.org/r/20201120180452.19071-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following sparse warnings:
mm/page_alloc.c:3040:6: warning: symbol '__drain_all_pages' was not declared. Should it be static?
mm/page_alloc.c:6349:6: warning: symbol '__zone_set_pageset_high_and_batch' was not declared. Should it be static?
Link: https://lkml.kernel.org/r/1605517365-65858-1-git-send-email-zou_wei@huawei.com
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide some guidance towards when this might not be the right interface
to use.
Link: https://lkml.kernel.org/r/20201027025523.3235-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Memory offlining relies on page isolation to guarantee a forward progress
because pages cannot be reused while they are isolated. But the page
isolation itself doesn't prevent from races while freed pages are stored
on pcp lists and thus can be reused. This can be worked around by
repeated draining of pcplists, as done by commit 9683182612
("mm/memory_hotplug: drain per-cpu pages again during memory offline").
David and Michal would prefer that this race was closed in a way that
callers of page isolation who need stronger guarantees don't need to
repeatedly drain. David suggested disabling pcplists usage completely
during page isolation, instead of repeatedly draining them.
To achieve this without adding special cases in alloc/free fastpath, we
can use the same approach as boot pagesets - when pcp->high is 0, any
pcplist addition will be immediately flushed.
The race can thus be closed by setting pcp->high to 0 and draining
pcplists once, before calling start_isolate_page_range(). The draining
will serialize after processes that already disabled interrupts and read
the old value of pcp->high in free_unref_page_commit(), and processes that
have not yet disabled interrupts, will observe pcp->high == 0 when they
are rescheduled, and skip pcplists. This guarantees no stray pages on
pcplists in zones where isolation happens.
This patch thus adds zone_pcp_disable() and zone_pcp_enable() functions
that page isolation users can call before start_isolate_page_range() and
after unisolating (or offlining) the isolated pages.
Also, drain_all_pages() is optimized to only execute on cpus where
pcplists are not empty. The check can however race with a free to pcplist
that has not yet increased the pcp->count from 0 to 1. Thus make the
drain optionally skip the racy check and drain on all cpus, and use this
option in zone_pcp_disable().
As we have to avoid external updates to high and batch while pcplists are
disabled, we take pcp_batch_high_lock in zone_pcp_disable() and release it
in zone_pcp_enable(). This also synchronizes multiple users of
zone_pcp_disable()/enable().
Currently the only user of this functionality is offline_pages().
[vbabka@suse.cz: add comment, per David]
Link: https://lkml.kernel.org/r/527480ef-ed72-e1c1-52a0-1c5b0113df45@suse.cz
Link: https://lkml.kernel.org/r/20201111092812.11329-8-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Suggested-by: David Hildenbrand <david@redhat.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, pcplists are drained during set_migratetype_isolate() which
means once per pageblock processed start_isolate_page_range(). This is
somewhat wasteful. Moreover, the callers might need different guarantees,
and the draining is currently prone to races and does not guarantee that
no page from isolated pageblock will end up on the pcplist after the
drain.
Better guarantees are added by later patches and require explicit actions
by page isolation users that need them. Thus it makes sense to move the
current imperfect draining to the callers also as a preparation step.
Link: https://lkml.kernel.org/r/20201111092812.11329-7-vbabka@suse.cz
Suggested-by: David Hildenbrand <david@redhat.com>
Suggested-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All per-cpu pagesets for a zone use the same high and batch values, that
are duplicated there just for performance (locality) reasons. This patch
adds the same variables also to struct zone as a shared copy.
This will be useful later for making possible to disable pcplists
temporarily by setting high value to 0, while remembering the values for
restoring them later. But we can also immediately benefit from not
updating pagesets of all possible cpus in case the newly recalculated
values (after sysctl change or memory online/offline) are actually
unchanged from the previous ones.
Link: https://lkml.kernel.org/r/20201111092812.11329-6-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pageset_update() attempts to update pcplist's high and batch values in a
way that readers don't observe batch > high. It uses smp_wmb() to order
the updates in a way to achieve this. However, without proper pairing
read barriers in readers this guarantee doesn't hold, and there are no
such barriers in e.g. free_unref_page_commit().
Commit 88e8ac11d2 ("mm, page_alloc: fix core hung in
free_pcppages_bulk()") already showed this is problematic, and solved this
by ultimately only trusing pcp->count of the current cpu with interrupts
disabled.
The update dance with unpaired write barriers thus makes no sense.
Replace them with plain WRITE_ONCE to prevent store tearing, and document
that the values can change asynchronously and should not be trusted for
correctness.
All current readers appear to be OK after 88e8ac11d2. Convert them to
READ_ONCE to prevent unnecessary read tearing, but mainly to alert anybody
making future changes to the code that special care is needed.
Link: https://lkml.kernel.org/r/20201111092812.11329-5-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We initialize boot-time pagesets with setup_pageset(), which sets high and
batch values that effectively disable pcplists.
We can remove this wrapper if we just set these values for all pagesets in
pageset_init(). Non-boot pagesets then subsequently update them to the
proper values.
No functional change.
Link: https://lkml.kernel.org/r/20201111092812.11329-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We currently call pageset_set_high_and_batch() for each possible cpu,
which repeats the same calculations of high and batch values.
Instead call the function just once per zone, and make it apply the
calculated values to all per-cpu pagesets of the zone.
This also allows removing the zone_pageset_init() and __zone_pcp_update()
wrappers.
No functional change.
Link: https://lkml.kernel.org/r/20201111092812.11329-3-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "disable pcplists during memory offline", v3.
As per the discussions [1] [2] this is an attempt to implement David's
suggestion that page isolation should disable pcplists to avoid races with
page freeing in progress. This is done without extra checks in fast
paths, as explained in Patch 9. The repeated draining done by [2] is then
no longer needed. Previous version (RFC) is at [3].
The RFC tried to hide pcplists disabling/enabling into page isolation, but
it wasn't completely possible, as memory offline does not unisolation.
Michal suggested an explicit API in [4] so that's the current
implementation and it seems indeed nicer.
Once we accept that page isolation users need to do explicit actions
around it depending on the needed guarantees, we can also IMHO accept that
the current pcplist draining can be also done by the callers, which is
more effective. After all, there are only two users of page isolation.
So patch 6 does effectively the same thing as Pavel proposed in [5], and
patch 7 implement stronger guarantees only for memory offline. If CMA
decides to opt-in to the stronger guarantee, it can be added later.
Patches 1-5 are preparatory cleanups for pcplist disabling.
Patchset was briefly tested in QEMU so that memory online/offline works,
but I haven't done a stress test that would prove the race fixed by [2] is
eliminated.
Note that patch 7 could be avoided if we instead adjusted page freeing in
shown in [6], but I believe the current implementation of disabling
pcplists is not too much complex, so I would prefer this instead of adding
new checks and longer irq-disabled section into page freeing hotpaths.
[1] https://lore.kernel.org/linux-mm/20200901124615.137200-1-pasha.tatashin@soleen.com/
[2] https://lore.kernel.org/linux-mm/20200903140032.380431-1-pasha.tatashin@soleen.com/
[3] https://lore.kernel.org/linux-mm/20200907163628.26495-1-vbabka@suse.cz/
[4] https://lore.kernel.org/linux-mm/20200909113647.GG7348@dhcp22.suse.cz/
[5] https://lore.kernel.org/linux-mm/20200904151448.100489-3-pasha.tatashin@soleen.com/
[6] https://lore.kernel.org/linux-mm/3d3b53db-aeaa-ff24-260b-36427fac9b1c@suse.cz/
[7] https://lore.kernel.org/linux-mm/20200922143712.12048-1-vbabka@suse.cz/
[8] https://lore.kernel.org/linux-mm/20201008114201.18824-1-vbabka@suse.cz/
This patch (of 7):
The updates to pcplists' high and batch values are handled by multiple
functions that make the calculations hard to follow. Consolidate
everything to pageset_set_high_and_batch() and remove pageset_set_batch()
and pageset_set_high() wrappers.
The only special case using one of the removed wrappers was:
build_all_zonelists_init()
setup_pageset()
pageset_set_batch()
which was hardcoding batch as 0, so we can just open-code a call to
pageset_update() with constant parameters instead.
No functional change.
Link: https://lkml.kernel.org/r/20201111092812.11329-1-vbabka@suse.cz
Link: https://lkml.kernel.org/r/20201111092812.11329-2-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "arch, mm: improve robustness of direct map manipulation", v7.
During recent discussion about KVM protected memory, David raised a
concern about usage of __kernel_map_pages() outside of DEBUG_PAGEALLOC
scope [1].
Indeed, for architectures that define CONFIG_ARCH_HAS_SET_DIRECT_MAP it is
possible that __kernel_map_pages() would fail, but since this function is
void, the failure will go unnoticed.
Moreover, there's lack of consistency of __kernel_map_pages() semantics
across architectures as some guard this function with #ifdef
DEBUG_PAGEALLOC, some refuse to update the direct map if page allocation
debugging is disabled at run time and some allow modifying the direct map
regardless of DEBUG_PAGEALLOC settings.
This set straightens this out by restoring dependency of
__kernel_map_pages() on DEBUG_PAGEALLOC and updating the call sites
accordingly.
Since currently the only user of __kernel_map_pages() outside
DEBUG_PAGEALLOC is hibernation, it is updated to make direct map accesses
there more explicit.
[1] https://lore.kernel.org/lkml/2759b4bf-e1e3-d006-7d86-78a40348269d@redhat.com
This patch (of 4):
When CONFIG_DEBUG_PAGEALLOC is enabled, it unmaps pages from the kernel
direct mapping after free_pages(). The pages than need to be mapped back
before they could be used. Theese mapping operations use
__kernel_map_pages() guarded with with debug_pagealloc_enabled().
The only place that calls __kernel_map_pages() without checking whether
DEBUG_PAGEALLOC is enabled is the hibernation code that presumes
availability of this function when ARCH_HAS_SET_DIRECT_MAP is set. Still,
on arm64, __kernel_map_pages() will bail out when DEBUG_PAGEALLOC is not
enabled but set_direct_map_invalid_noflush() may render some pages not
present in the direct map and hibernation code won't be able to save such
pages.
To make page allocation debugging and hibernation interaction more robust,
the dependency on DEBUG_PAGEALLOC or ARCH_HAS_SET_DIRECT_MAP has to be
made more explicit.
Start with combining the guard condition and the call to
__kernel_map_pages() into debug_pagealloc_map_pages() and
debug_pagealloc_unmap_pages() functions to emphasize that
__kernel_map_pages() should not be called without DEBUG_PAGEALLOC and use
these new functions to map/unmap pages when page allocation debugging is
enabled.
Link: https://lkml.kernel.org/r/20201109192128.960-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20201109192128.960-2-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ARM and ARM64 free unused parts of the memory map just before the
initialization of the page allocator. To allow holes in the memory map both
architectures overload pfn_valid() and define HAVE_ARCH_PFN_VALID.
Allowing holes in the memory map for FLATMEM may be useful for small
machines, such as ARC and m68k and will enable those architectures to cease
using DISCONTIGMEM and still support more than one memory bank.
Move the functions that free unused memory map to generic mm and enable
them in case HAVE_ARCH_PFN_VALID=y.
Link: https://lkml.kernel.org/r/20201101170454.9567-10-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ARM is the only architecture that defines CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
which in turn enables memmap_valid_within() function that is intended to
verify existence of struct page associated with a pfn when there are holes
in the memory map.
However, the ARCH_HAS_HOLES_MEMORYMODEL also enables HAVE_ARCH_PFN_VALID
and arch-specific pfn_valid() implementation that also deals with the holes
in the memory map.
The only two users of memmap_valid_within() call this function after
a call to pfn_valid() so the memmap_valid_within() check becomes redundant.
Remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL and memmap_valid_within() and rely
entirely on ARM's implementation of pfn_valid() that is now enabled
unconditionally.
Link: https://lkml.kernel.org/r/20201101170454.9567-9-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ia64 implementation of __early_pfn_to_nid() essentially relies on the
same data as the generic implementation.
The correspondence between memory ranges and nodes is set in memblock
during early memory initialization in register_active_ranges() function.
The initialization of sparsemem that requires early_pfn_to_nid() happens
later and it can use the memblock information like the other architectures.
Link: https://lkml.kernel.org/r/20201101170454.9567-3-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The aux_stack[2] is reused to record the call_rcu() call stack and
enqueuing work call stacks. So that we need to change the auxiliary stack
title for common title, print them in KASAN report.
Link: https://lkml.kernel.org/r/20201203022715.30635-1-walter-zh.wu@mediatek.com
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Suggested-by: Marco Elver <elver@google.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The size of vm area can be affected by the presence or not of the guard
page. In particular when VM_NO_GUARD is present, the actual accessible
size has to be considered like the real size minus the guard page.
Currently kasan does not keep into account this information during the
poison operation and in particular tries to poison the guard page as well.
This approach, even if incorrect, does not cause an issue because the tags
for the guard page are written in the shadow memory. With the future
introduction of the Tag-Based KASAN, being the guard page inaccessible by
nature, the write tag operation on this page triggers a fault.
Fix kasan shadow poisoning size invoking get_vm_area_size() instead of
accessing directly the field in the data structure to detect the correct
value.
Link: https://lkml.kernel.org/r/20201027160213.32904-1-vincenzo.frascino@arm.com
Fixes: d98c9e83b5 ("kasan: fix crashes on access to memory mapped by vm_map_ram()")
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When multiple locks are acquired, they should be released in reverse
order. For s_start() and s_stop() in mm/vmalloc.c, that is not the
case.
s_start: mutex_lock(&vmap_purge_lock); spin_lock(&vmap_area_lock);
s_stop : mutex_unlock(&vmap_purge_lock); spin_unlock(&vmap_area_lock);
This unlock sequence, though allowed, is not optimal. If a waiter is
present, mutex_unlock() will need to go through the slowpath of waking
up the waiter with preemption disabled. Fix that by releasing the
spinlock first before the mutex.
Link: https://lkml.kernel.org/r/20201213180843.16938-1-longman@redhat.com
Fixes: e36176be1c ("mm/vmalloc: rework vmap_area_lock")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kernel-doc markup has a issue on pvm_determine_end_from_reverse:
mm/vmalloc.c:3145: warning: Function parameter or member 'align' not described in 'pvm_determine_end_from_reverse'
Add a explanation for it to remove the warning.
Link: https://lkml.kernel.org/r/1605605088-30668-3-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A current "lazy drain" model suffers from at least two issues.
First one is related to the unsorted list of vmap areas, thus in order to
identify the [min:max] range of areas to be drained, it requires a full
list scan. What is a time consuming if the list is too long.
Second one and as a next step is about merging all fragments with a free
space. What is also a time consuming because it has to iterate over
entire list which holds outstanding lazy areas.
See below the "preemptirqsoff" tracer that illustrates a high latency. It
is ~24676us. Our workloads like audio and video are effected by such long
latency:
<snip>
tracer: preemptirqsoff
preemptirqsoff latency trace v1.1.5 on 4.9.186-perf+
--------------------------------------------------------------------
latency: 24676 us, #4/4, CPU#1 | (M:preempt VP:0, KP:0, SP:0 HP:0 P:8)
-----------------
| task: crtc_commit:112-261 (uid:0 nice:0 policy:1 rt_prio:16)
-----------------
=> started at: __purge_vmap_area_lazy
=> ended at: __purge_vmap_area_lazy
_------=> CPU#
/ _-----=> irqs-off
| / _----=> need-resched
|| / _---=> hardirq/softirq
||| / _--=> preempt-depth
|||| / delay
cmd pid ||||| time | caller
\ / ||||| \ | /
crtc_com-261 1...1 1us*: _raw_spin_lock <-__purge_vmap_area_lazy
[...]
crtc_com-261 1...1 24675us : _raw_spin_unlock <-__purge_vmap_area_lazy
crtc_com-261 1...1 24677us : trace_preempt_on <-__purge_vmap_area_lazy
crtc_com-261 1...1 24683us : <stack trace>
=> free_vmap_area_noflush
=> remove_vm_area
=> __vunmap
=> vfree
=> drm_property_free_blob
=> drm_mode_object_unreference
=> drm_property_unreference_blob
=> __drm_atomic_helper_crtc_destroy_state
=> sde_crtc_destroy_state
=> drm_atomic_state_default_clear
=> drm_atomic_state_clear
=> drm_atomic_state_free
=> complete_commit
=> _msm_drm_commit_work_cb
=> kthread_worker_fn
=> kthread
=> ret_from_fork
<snip>
To address those two issues we can redesign a purging of the outstanding
lazy areas. Instead of queuing vmap areas to the list, we replace it by
the separate rb-tree. In hat case an area is located in the tree/list in
ascending order. It will give us below advantages:
a) Outstanding vmap areas are merged creating bigger coalesced blocks,
thus it becomes less fragmented.
b) It is possible to calculate a flush range [min:max] without scanning
all elements. It is O(1) access time or complexity;
c) The final merge of areas with the rb-tree that represents a free
space is faster because of (a). As a result the lock contention is
also reduced.
Link: https://lkml.kernel.org/r/20201116220033.1837-2-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: huang ying <huang.ying.caritas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a dedicated and separate function that finds and removes a
continuous kernel virtual area. As a final step it also releases the
"area", a descriptor of corresponding vm_struct.
Use free_vmap_area() in the __vmalloc_node_range() instead of open coded
steps which are exactly the same, to perform a cleanup.
Link: https://lkml.kernel.org/r/20201116220033.1837-1-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With a machine with 3 TB (more than 2 TB memory). If you use vmalloc to
allocate > 2 TB memory, the array_size below will be overflowed.
The array_size is an unsigned int and can only be used to allocate less
than 2 TB memory. If you pass 2*1028*1028*1024*1024 = 2 * 2^40 in the
argument of vmalloc. The array_size will become 2*2^31 = 2^32. The 2^32
cannot be store with a 32 bit integer.
The fix is to change the type of array_size to unsigned long.
[akpm@linux-foundation.org: rework for current mainline]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=210023
Reported-by: <hsinhuiwu@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Extracted from slab.h, which seems to have the most complete version
including the correct might_sleep() check. Roll it out to slob.c.
Motivated by a discussion with Paul about possibly changing call_rcu
behaviour to allocate memory, but only roughly every 500th call.
There are a lot fewer places in the kernel that care about whether
allocating memory is allowed or not (due to deadlocks with reclaim code)
than places that care whether sleeping is allowed. But debugging these
also tends to be a lot harder, so nice descriptive checks could come in
handy. I might have some use eventually for annotations in drivers/gpu.
Note that unlike fs_reclaim_acquire/release gfpflags_allow_blocking does
not consult the PF_MEMALLOC flags. But there is no flag equivalent for
GFP_NOWAIT, hence this check can't go wrong due to
memalloc_no*_save/restore contexts. Willy is working on a patch series
which might change this:
https://lore.kernel.org/linux-mm/20200625113122.7540-7-willy@infradead.org/
I think best would be if that updates gfpflags_allow_blocking(), since
there's a ton of callers all over the place for that already.
Link: https://lkml.kernel.org/r/20201125162532.1299794-3-daniel.vetter@ffwll.ch
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Michel Lespinasse <walken@google.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Waiman Long <longman@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Qian Cai <cai@lca.pw>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Christian König <christian.koenig@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thomas Hellström (Intel) <thomas_os@shipmail.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs_reclaim_acquire/release nicely catch recursion issues when allocating
GFP_KERNEL memory against shrinkers (which gpu drivers tend to use to keep
the excessive caches in check). For mmu notifier recursions we do have
lockdep annotations since 23b68395c7 ("mm/mmu_notifiers: add a lockdep
map for invalidate_range_start/end").
But these only fire if a path actually results in some pte invalidation -
for most small allocations that's very rarely the case. The other trouble
is that pte invalidation can happen any time when __GFP_RECLAIM is set.
Which means only really GFP_ATOMIC is a safe choice, GFP_NOIO isn't good
enough to avoid potential mmu notifier recursion.
I was pondering whether we should just do the general annotation, but
there's always the risk for false positives. Plus I'm assuming that the
core fs and io code is a lot better reviewed and tested than random mmu
notifier code in drivers. Hence why I decide to only annotate for that
specific case.
Furthermore even if we'd create a lockdep map for direct reclaim, we'd
still need to explicit pull in the mmu notifier map - there's a lot more
places that do pte invalidation than just direct reclaim, these two
contexts arent the same.
Note that the mmu notifiers needing their own independent lockdep map is
also the reason we can't hold them from fs_reclaim_acquire to
fs_reclaim_release - it would nest with the acquistion in the pte
invalidation code, causing a lockdep splat. And we can't remove the
annotations from pte invalidation and all the other places since they're
called from many other places than page reclaim. Hence we can only do the
equivalent of might_lock, but on the raw lockdep map.
With this we can also remove the lockdep priming added in 66204f1d2d
("mm/mmu_notifiers: prime lockdep") since the new annotations are strictly
more powerful.
Link: https://lkml.kernel.org/r/20201125162532.1299794-2-daniel.vetter@ffwll.ch
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Thomas Hellström (Intel) <thomas_os@shipmail.org>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't allow splitting of vm_special_mapping's. It affects vdso/vvar
areas. Uprobes have only one page in xol_area so they aren't affected.
Those restrictions were enforced by checks in .mremap() callbacks.
Restrict resizing with generic .split() callback.
Link: https://lkml.kernel.org/r/20201013013416.390574-7-dima@arista.com
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If original VMA can't be split at the desired address, do_munmap() will
fail and leave both new-copied VMA and old VMA. De-facto it's
MREMAP_DONTUNMAP behaviour, which is unexpected.
Currently, it may fail such way for hugetlbfs and dax device mappings.
Minimize such unpleasant situations to OOM by checking .may_split() before
attempting to create a VMA copy.
Link: https://lkml.kernel.org/r/20201013013416.390574-6-dima@arista.com
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename the callback to reflect that it's not called *on* or *after* split,
but rather some time before the splitting to check if it's possible.
Link: https://lkml.kernel.org/r/20201013013416.390574-5-dima@arista.com
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As kernel expect to see only one of such mappings, any further operations
on the VMA-copy may be unexpected by the kernel. Maybe it's being on the
safe side, but there doesn't seem to be any expected use-case for this, so
restrict it now.
Link: https://lkml.kernel.org/r/20201013013416.390574-4-dima@arista.com
Fixes: commit e346b38130 ("mm/mremap: add MREMAP_DONTUNMAP to mremap()")
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently memory is accounted post-mremap() with MREMAP_DONTUNMAP, which
may break overcommit policy. So, check if there's enough memory before
doing actual VMA copy.
Don't unset VM_ACCOUNT on MREMAP_DONTUNMAP. By semantics, such mremap()
is actually a memory allocation. That also simplifies the error-path a
little.
Also, as it's memory allocation on success don't reset hiwater_vm value.
Link: https://lkml.kernel.org/r/20201013013416.390574-3-dima@arista.com
Fixes: commit e346b38130 ("mm/mremap: add MREMAP_DONTUNMAP to mremap()")
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mremap: move_vma() fixes".
This patch (of 6):
move_vma() copies VMA without adding it to account, then unmaps old part
of VMA. On failure it unmaps the new VMA. With hacks accounting in
munmap is disabled as it's a copy of existing VMA.
Account the memory on munmap() failure which was previously copied into
a new VMA.
Link: https://lkml.kernel.org/r/20201013013416.390574-1-dima@arista.com
Link: https://lkml.kernel.org/r/20201013013416.390574-2-dima@arista.com
Fixes: commit e2ea83742133 ("[PATCH] mremap: move_vma fixes and cleanup")
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Code outside mm/ should not be calling free_unref_page(). Also move
free_unref_page_list().
Link: https://lkml.kernel.org/r/20201125034655.27687-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The goal of these tracepoints is to be able to debug lock contention
issues. This lock is acquired on most (all?) mmap / munmap / page fault
operations, so a multi-threaded process which does a lot of these can
experience significant contention.
We trace just before we start acquisition, when the acquisition returns
(whether it succeeded or not), and when the lock is released (or
downgraded). The events are broken out by lock type (read / write).
The events are also broken out by memcg path. For container-based
workloads, users often think of several processes in a memcg as a single
logical "task", so collecting statistics at this level is useful.
The end goal is to get latency information. This isn't directly included
in the trace events. Instead, users are expected to compute the time
between "start locking" and "acquire returned", using e.g. synthetic
events or BPF. The benefit we get from this is simpler code.
Because we use tracepoint_enabled() to decide whether or not to trace,
this patch has effectively no overhead unless tracepoints are enabled at
runtime. If tracepoints are enabled, there is a performance impact, but
how much depends on exactly what e.g. the BPF program does.
[axelrasmussen@google.com: fix use-after-free race and css ref leak in tracepoints]
Link: https://lkml.kernel.org/r/20201130233504.3725241-1-axelrasmussen@google.com
[axelrasmussen@google.com: v3]
Link: https://lkml.kernel.org/r/20201207213358.573750-1-axelrasmussen@google.com
[rostedt@goodmis.org: in-depth examples of tracepoint_enabled() usage, and per-cpu-per-context buffer design]
Link: https://lkml.kernel.org/r/20201105211739.568279-2-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
check_pte() needs a correct colon for kernel-doc markup, otherwise, gcc
has the following warning for W=1, mm/page_vma_mapped.c:86: warning:
Function parameter or member 'pvmw' not described in 'check_pte'
Link: https://lkml.kernel.org/r/1605597167-25145-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add and change parameter explanation for wp_pte and clean_record_pte, to
avoid W1 warning:
mm/mapping_dirty_helpers.c:34: warning: Function parameter or member 'end' not described in 'wp_pte'
mm/mapping_dirty_helpers.c:88: warning: Function parameter or member 'end' not described in 'clean_record_pte'
Link: https://lkml.kernel.org/r/1605605088-30668-2-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Despite a comment that said that page fault accounting would be charged to
whatever task_struct* was passed into __access_remote_vm(), the tsk
argument was actually unused.
Making page fault accounting actually use this task struct is quite a
project, so there is no point in keeping the tsk argument.
Delete both the comment, and the argument.
[rppt@linux.ibm.com: changelog addition]
Link: https://lkml.kernel.org/r/20201026074137.4147787-1-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Android needs to move large memory regions for garbage collection. The GC
requires moving physical pages of multi-gigabyte heap using mremap.
During this move, the application threads have to be paused for
correctness. It is critical to keep this pause as short as possible to
avoid jitters during user interaction.
Optimize mremap for >= 1GB-sized regions by moving at the PUD/PGD level if
the source and destination addresses are PUD-aligned. For
CONFIG_PGTABLE_LEVELS == 3, moving at the PUD level in effect moves PGD
entries, since the PUD entry is “folded back” onto the PGD entry. Add
HAVE_MOVE_PUD so that architectures where moving at the PUD level isn't
supported/tested can turn this off by not selecting the config.
Link: https://lkml.kernel.org/r/20201014005320.2233162-4-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Hassan Naveed <hnaveed@wavecomp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jia He <justin.he@arm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For many workloads, pagetable consumption is significant and it makes
sense to expose it in the memory.stat for the memory cgroups. However at
the moment, the pagetables are accounted per-zone. Converting them to
per-node and using the right interface will correctly account for the
memory cgroups as well.
[akpm@linux-foundation.org: export __mod_lruvec_page_state to modules for arch/mips/kvm/]
Link: https://lkml.kernel.org/r/20201130212541.2781790-3-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "memcg: add pagetable comsumption to memory.stat", v2.
Many workloads consumes significant amount of memory in pagetables. One
specific use-case is the user space network driver which mmaps the
application memory to provide zero copy transfer. This driver can consume
a large amount memory in page tables. This patch series exposes the
pagetable comsumption for each memory cgroup.
This patch (of 2):
This does not change any functionality and only move the functions which
update the lruvec stats to vmstat.h from memcontrol.h. The main reason
for this patch is to be able to use these functions in the page table
contructor function which is defined in mm.h and we can not include the
memcontrol.h in that file. Also this is a better place for this interface
in general. The lruvec abstraction, while invented for memcg, isn't
specific to memcg at all.
Link: https://lkml.kernel.org/r/20201130212541.2781790-2-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Swapcache readahead pages are charged before being used, so it is unlikely
that they will be migrated before charging. Remove the incorrect comment.
Link: https://lkml.kernel.org/r/1605864930-49405-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The *_lruvec_slab_state is also suitable for pages allocated from buddy,
not just for the slab objects. But the function name seems to tell us
that only slab object is applicable. So we can rename the keyword of slab
to kmem.
Link: https://lkml.kernel.org/r/20201117085249.24319-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 2ef1bf118c40 ("mm: memcg: deprecate the non-hierarchical mode")
removed the only use of memcg_has_children() in
mem_cgroup_hierarchy_write() as part of the feature deprecation.
Hence, since then, make CC=clang W=1 warns:
mm/memcontrol.c:3421:20: warning: unused function 'memcg_has_children' [-Wunused-function]
Simply remove this obsolete unused function.
Link: https://lkml.kernel.org/r/20201116055043.20886-1-lukas.bulwahn@gmail.com
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: memcg: deprecate cgroup v1 non-hierarchical mode", v1.
The non-hierarchical cgroup v1 mode is a legacy of early days
of the memory controller and doesn't bring any value today.
However, it complicates the code and creates many edge cases
all over the memory controller code.
It's a good time to deprecate it completely. This patchset removes
the internal logic, adjusts the user interface and updates
the documentation. The alt patch removes some bits of the cgroup
core code, which become obsolete.
Michal Hocko said:
"All that we know today is that we have a warning in place to complain
loudly when somebody relies on use_hierarchy=0 with a deeper
hierarchy. For all those years we have seen _zero_ reports that would
describe a sensible usecase.
Moreover we (SUSE) have backported this warning into old distribution
kernels (since 3.0 based kernels) to extend the coverage and didn't
hear even for users who adopt new kernels only very slowly. The only
report we have seen so far was a LTP test suite which doesn't really
reflect any real life usecase"
This patch (of 3):
The non-hierarchical cgroup v1 mode is a legacy of early days of the
memory controller and doesn't bring any value today. However, it
complicates the code and creates many edge cases all over the memory
controller code.
It's a good time to deprecate it completely.
Functionally this patch enabled is by default for all cgroups and forbids
switching it off. Nothing changes if cgroup v2 is used: hierarchical mode
was enforced from scratch.
To protect the ABI memory.use_hierarchy interface is preserved with a
limited functionality: reading always returns "1", writing of "1" passes
silently, writing of any other value fails with -EINVAL and a warning to
dmesg (on the first occasion).
Link: https://lkml.kernel.org/r/20201110220800.929549-1-guro@fb.com
Link: https://lkml.kernel.org/r/20201110220800.929549-2-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes/removes some obsolete comments in the code related
to the kernel memory accounting:
- kmem_cache->memcg_params.memcg_caches has been removed by commit
9855609bde ("mm: memcg/slab: use a single set of kmem_caches for
all accounted allocations")
- memcg->kmemcg_id is not used as a gate for kmem accounting since
commit 0b8f73e104 ("mm: memcontrol: clean up alloc, online,
offline, free functions")
Link: https://lkml.kernel.org/r/20201110184615.311974-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The page->mem_cgroup member is replaced by memcg_data, and add a helper
page_memcg() for it. Need to update comments to avoid confusing.
Link: https://lkml.kernel.org/r/1491c150-1cc0-6062-08ea-9c891548a3bc@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 369ea8242c ("mm/rmap: update to new mmu_notifier semantic
v2"), the code to check the secondary MMU's page table access bit is
broken for !(TTU_IGNORE_ACCESS) because the page is unmapped from the
secondary MMU's page table before the check. More specifically for those
secondary MMUs which unmap the memory in
mmu_notifier_invalidate_range_start() like kvm.
However memory reclaim is the only user of !(TTU_IGNORE_ACCESS) or the
absence of TTU_IGNORE_ACCESS and it explicitly performs the page table
access check before trying to unmap the page. So, at worst the reclaim
will miss accesses in a very short window if we remove page table access
check in unmapping code.
There is an unintented consequence of !(TTU_IGNORE_ACCESS) for the memcg
reclaim. From memcg reclaim the page_referenced() only account the
accesses from the processes which are in the same memcg of the target page
but the unmapping code is considering accesses from all the processes, so,
decreasing the effectiveness of memcg reclaim.
The simplest solution is to always assume TTU_IGNORE_ACCESS in unmapping
code.
Link: https://lkml.kernel.org/r/20201104231928.1494083-1-shakeelb@google.com
Fixes: 369ea8242c ("mm/rmap: update to new mmu_notifier semantic v2")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The rcu_read_lock/unlock only can guarantee that the memcg will not be
freed, but it cannot guarantee the success of css_get to memcg.
If the whole process of a cgroup offlining is completed between reading a
objcg->memcg pointer and bumping the css reference on another CPU, and
there are exactly 0 external references to this memory cgroup (how we get
to the obj_cgroup_charge() then?), css_get() can change the ref counter
from 0 back to 1.
Link: https://lkml.kernel.org/r/20201028035013.99711-2-songmuchun@bytedance.com
Fixes: bf4f059954 ("mm: memcg/slab: obj_cgroup API")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Consider the following memcg hierarchy.
root
/ \
A B
If we failed to get the reference on objcg of memcg A, the
get_obj_cgroup_from_current can return the wrong objcg for the root
memcg.
Link: https://lkml.kernel.org/r/20201029164429.58703-1-songmuchun@bytedance.com
Fixes: bf4f059954 ("mm: memcg/slab: obj_cgroup API")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Eugene Syromiatnikov <esyr@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Adrian Reber <areber@redhat.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The mz->usage_in_excess >= mz_node->usage_in_excess check is exactly the
else case of mz->usage_in_excess < mz_node->usage_in_excess. So we could
replace else if (mz->usage_in_excess >= mz_node->usage_in_excess) with
else equally. Also drop the comment which doesn't really explain much.
Link: https://lkml.kernel.org/r/20201012131607.10656-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 991e767385 ("mm: memcontrol: account kernel stack per
node") there is no user of the mod_memcg_obj_state(). So just remove
it.
Also rework type of the idx parameter of the mod_objcg_state() from int
to enum node_stat_item.
Link: https://lkml.kernel.org/r/20201013153504.92602-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As huge page usage in the page cache and for shmem files proliferates in
our production environment, the performance monitoring team has asked for
per-cgroup stats on those pages.
We already track and export anon_thp per cgroup. We already track file
THP and shmem THP per node, so making them per-cgroup is only a matter of
switching from node to lruvec counters. All callsites are in places where
the pages are charged and locked, so page->memcg is stable.
[hannes@cmpxchg.org: add documentation]
Link: https://lkml.kernel.org/r/20201026174029.GC548555@cmpxchg.org
Link: https://lkml.kernel.org/r/20201022151844.489337-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
shmem_mapping() isn't worth an out-of-line call from any callsite.
So make it inline by
- make shmem_aops global
- export shmem_aops
- inline the shmem_mapping()
and replace the direct call 'shmem_aops' with shmem_mapping()
in shmem.c.
Link: https://lkml.kernel.org/r/20201115165207.GA265355@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the merge of commit 2e16929660 ("ceph: have ceph_writepages_start
call pagevec_lookup_range_tag"), nothing calls this anymore.
Link: https://lkml.kernel.org/r/20201021193926.101474-1-jlayton@kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We could use helper memset to fill the swap_map with SWAP_HAS_CACHE instead
of a direct loop here to simplify the code. Also we can remove the local
variable i and map this way.
Link: https://lkml.kernel.org/r/20200921122224.7139-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the code went to the out label, it must have p == NULL. So what out
label really does is redundant if check and return err. We should Remove
this unnecessary out label because it does not handle resource free and so
on.
Link: https://lkml.kernel.org/r/20201009130337.29698-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
swap_ra_info() may leave ra_info untouched in non_swap_entry() case as
page table lock is not held. In this case, we have ra_info.nr_pte == 0
and it is meaningless to continue with swap cache readahead. Skip such
ops by init ra_info.win = 1.
[akpm@linux-foundation.org: clean up struct init]
Link: https://lkml.kernel.org/r/20201009133059.58407-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 570a335b8e ("swap_info: swap count continuations") introduced the
func add_swap_count_continuation() but forgot to use the helper function
swap_count() introduced by commit 355cfa73dd ("mm: modify swap_map and
add SWAP_HAS_CACHE flag").
Link: https://lkml.kernel.org/r/20201009134306.18033-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
release_pages() is an optimized, inlined version of __put_pages() except
that zone device struct pages that are not page_is_devmap_managed() (i.e.,
memory_type MEMORY_DEVICE_GENERIC and MEMORY_DEVICE_PCI_P2PDMA), fall
through to the code that could return the zone device page to the page
allocator instead of adjusting the pgmap reference count.
Clearly these type of pages are not having the reference count decremented
to zero via release_pages() or page allocation problems would be seen.
Just to be safe, handle the 1 to zero case in release_pages() like
__put_page() does.
Link: https://lkml.kernel.org/r/20201021194733.11530-1-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These functions accomplish the same thing but have different
implementations.
unpin_user_page() has a bug where it calls mod_node_page_state() after
calling put_page() which creates a risk that the page could have been
hot-uplugged from the system.
Fix this by using put_compound_head() as the only implementation.
__unpin_devmap_managed_user_page() and related can be deleted as well in
favour of the simpler, but slower, version in put_compound_head() that has
an extra atomic page_ref_sub, but always calls put_page() which internally
contains the special devmap code.
Move put_compound_head() to be directly after try_grab_compound_head() so
people can find it in future.
Link: https://lkml.kernel.org/r/0-v1-6730d4ee0d32+40e6-gup_combine_put_jgg@nvidia.com
Fixes: 1970dc6f52 ("mm/gup: /proc/vmstat: pin_user_pages (FOLL_PIN) reporting")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
CC: Joao Martins <joao.m.martins@oracle.com>
CC: Jonathan Corbet <corbet@lwn.net>
CC: Dan Williams <dan.j.williams@intel.com>
CC: Dave Chinner <david@fromorbit.com>
CC: Christoph Hellwig <hch@infradead.org>
CC: Jane Chu <jane.chu@oracle.com>
CC: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
CC: Michal Hocko <mhocko@suse.com>
CC: Mike Kravetz <mike.kravetz@oracle.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Muchun Song <songmuchun@bytedance.com>
CC: Vlastimil Babka <vbabka@suse.cz>
CC: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Long ago there wasn't a FOLL_LONGTERM flag so this DAX check was done by
post-processing the VMA list.
These days it is trivial to just check each VMA to see if it is DAX before
processing it inside __get_user_pages() and return failure if a DAX VMA is
encountered with FOLL_LONGTERM.
Removing the allocation of the VMA list is a significant speed up for many
call sites.
Add an IS_ENABLED to vma_is_fsdax so that code generation is unchanged
when DAX is compiled out.
Remove the dummy version of __gup_longterm_locked() as !CONFIG_CMA already
makes memalloc_nocma_save(), check_and_migrate_cma_pages(), and
memalloc_nocma_restore() into a NOP.
Link: https://lkml.kernel.org/r/0-v1-5551df3ed12e+b8-gup_dax_speedup_jgg@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 70e806e4e6 ("mm: Do early cow for pinned pages during
fork() for ptes") pages under a FOLL_PIN will not be write protected
during COW for fork. This means that pages returned from
pin_user_pages(FOLL_WRITE) should not become write protected while the pin
is active.
However, there is a small race where get_user_pages_fast(FOLL_PIN) can
establish a FOLL_PIN at the same time copy_present_page() is write
protecting it:
CPU 0 CPU 1
get_user_pages_fast()
internal_get_user_pages_fast()
copy_page_range()
pte_alloc_map_lock()
copy_present_page()
atomic_read(has_pinned) == 0
page_maybe_dma_pinned() == false
atomic_set(has_pinned, 1);
gup_pgd_range()
gup_pte_range()
pte_t pte = gup_get_pte(ptep)
pte_access_permitted(pte)
try_grab_compound_head()
pte = pte_wrprotect(pte)
set_pte_at();
pte_unmap_unlock()
// GUP now returns with a write protected page
The first attempt to resolve this by using the write protect caused
problems (and was missing a barrrier), see commit f3c64eda3e ("mm: avoid
early COW write protect games during fork()")
Instead wrap copy_p4d_range() with the write side of a seqcount and check
the read side around gup_pgd_range(). If there is a collision then
get_user_pages_fast() fails and falls back to slow GUP.
Slow GUP is safe against this race because copy_page_range() is only
called while holding the exclusive side of the mmap_lock on the src
mm_struct.
[akpm@linux-foundation.org: coding style fixes]
Link: https://lore.kernel.org/r/CAHk-=wi=iCnYCARbPGjkVJu9eyYeZ13N64tZYLdOB8CP5Q_PLw@mail.gmail.com
Link: https://lkml.kernel.org/r/2-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com
Fixes: f3c64eda3e ("mm: avoid early COW write protect games during fork()")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: "Ahmed S. Darwish" <a.darwish@linutronix.de> [seqcount_t parts]
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Add a seqcount between gup_fast and copy_page_range()", v4.
As discussed and suggested by Linus use a seqcount to close the small race
between gup_fast and copy_page_range().
Ahmed confirms that raw_write_seqcount_begin() is the correct API to use
in this case and it doesn't trigger any lockdeps.
I was able to test it using two threads, one forking and the other using
ibv_reg_mr() to trigger GUP fast. Modifying copy_page_range() to sleep
made the window large enough to reliably hit to test the logic.
This patch (of 2):
The next patch in this series makes the lockless flow a little more
complex, so move the entire block into a new function and remove a level
of indention. Tidy a bit of cruft:
- addr is always the same as start, so use start
- Use the modern check_add_overflow() for computing end = start + len
- nr_pinned/pages << PAGE_SHIFT needs the LHS to be unsigned long to
avoid shift overflow, make the variables unsigned long to avoid coding
casts in both places. nr_pinned was missing its cast
- The handling of ret and nr_pinned can be streamlined a bit
No functional change.
Link: https://lkml.kernel.org/r/0-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com
Link: https://lkml.kernel.org/r/1-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Without DEBUG_FS, all the code in gup_benchmark becomes meaningless.
For sure kernel provides debugfs stub while DEBUG_FS is disabled, but
the point here is that GUP_TEST can do nothing without DEBUG_FS.
[song.bao.hua@hisilicon.com: add comment as a prompt to users as commented by John and Randy]
Link: https://lkml.kernel.org/r/20201108083732.15336-1-song.bao.hua@hisilicon.com
Link: https://lkml.kernel.org/r/20201104100552.20156-1-song.bao.hua@hisilicon.com
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Suggested-by: John Garry <john.garry@huawei.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
gup_test_init() is only called during initialization, mark it as __init to
save some memory.
Link: https://lkml.kernel.org/r/20201103081016.16532-1-song.bao.hua@hisilicon.com
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For quite a while, I was doing a quick hack to gup_test.c (previously,
gup_benchmark.c) whenever I wanted to try out my changes to dump_page().
This makes that hack unnecessary, and instead allows anyone to easily get
the same coverage from a user space program. That saves a lot of time
because you don't have to change the kernel, in order to test different
pages and options.
The new sub-test takes advantage of the existing gup_test infrastructure,
which already provides a simple user space program, some allocated user
space pages, an ioctl call, pinning of those pages (via either
get_user_pages or pin_user_pages) and a corresponding kernel-side test
invocation. There's not much more required, mainly just a couple of
inputs from the user.
In fact, the new test re-uses the existing command line options in order
to get various helpful combinations (THP or normal, _fast or slow gup, gup
vs. pup, and more).
New command line options are: which pages to dump, and what type of
"get/pin" to use.
In order to figure out which pages to dump, the logic is:
* If the user doesn't specify anything, the page 0 (the first page in
the address range that the program sets up for testing) is dumped.
* Or, the user can type up to 8 page indices anywhere on the command
line. If you type more than 8, then it uses the first 8 and ignores the
remaining items.
For example:
./gup_test -ct -F 1 0 19 0x1000
Meaning:
-c: dump pages sub-test
-t: use THP pages
-F 1: use pin_user_pages() instead of get_user_pages()
0 19 0x1000: dump pages 0, 19, and 4096
Link: https://lkml.kernel.org/r/20201026064021.3545418-7-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Therefore, some minor cleanup and improvements are in order:
1. Rename the other items appropriately.
2. Stop reporting timing information on the non-benchmark items. It's
still being recorded and is available, but there's no point in
cluttering up the report with data that no one reasonably needs to
check.
3. Don't do iterations, for non-benchmark items.
4. Print out a shorter, more appropriate report for the non-benchmark
tests.
5. Add the command that was run, to the report. This really helps, as
there are quite a lot of options now.
6. Use a larger integer type for cmd, now that it's being compared
Otherwise it doesn't work, because in this case cmd is about 3 billion,
which is the perfect size for problems with signed vs unsigned int.
Link: https://lkml.kernel.org/r/20201026064021.3545418-6-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Avoid the need to copy-paste the gup_test ioctl commands and the struct
gup_test definition, between the kernel and the user space application, by
providing a new header file for these. This allows easier and safer
adding of new ioctl calls, as well as reducing the overall line count.
Details: The header file has to be able to compile independently, because
of the arguably unfortunate way that the Makefile is written: the Makefile
tries to build all of its prerequisites, when really it should be only
building the .c files, and leaving the other prerequisites (LOCAL_HDRS) as
pure dependencies.
That Makefile limitation is probably not worth fixing, but it explains why
one of the includes had to be moved into the new header file.
Also: simplify the ioctl struct (struct gup_test), by deleting the unused
__expansion[10] field. This sort of thing is what you might see in a
stable ABI, but this low-level, kernel-developer-oriented selftests/vm
system is very much not subject to ABI stability. So "expansion" and
"reserved" fields are unnecessary here.
Link: https://lkml.kernel.org/r/20201026064021.3545418-3-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "selftests/vm: gup_test, hmm-tests, assorted improvements", v3.
Summary: This series provides two main things, and a number of smaller
supporting goodies. The two main points are:
1) Add a new sub-test to gup_test, which in turn is a renamed version
of gup_benchmark. This sub-test allows nicer testing of dump_pages(),
at least on user-space pages.
For quite a while, I was doing a quick hack to gup_test.c whenever I
wanted to try out changes to dump_page(). Then Matthew Wilcox asked me
what I meant when I said "I used my dump_page() unit test", and I
realized that it might be nice to check in a polished up version of
that.
Details about how it works and how to use it are in the commit
description for patch #6 ("selftests/vm: gup_test: introduce the
dump_pages() sub-test").
2) Fixes a limitation of hmm-tests: these tests are incredibly useful,
but only if people actually build and run them. And it turns out that
libhugetlbfs is a little too effective at throwing a wrench in the
works, there. So I've added a little configuration check that removes
just two of the 21 hmm-tests, if libhugetlbfs is not available.
Further details in the commit description of patch #8
("selftests/vm: hmm-tests: remove the libhugetlbfs dependency").
Other smaller things that this series does:
a) Remove code duplication by creating gup_test.h.
b) Clear up the sub-test organization, and their invocation within
run_vmtests.sh.
c) Other minor assorted improvements.
[1] v2 is here:
https://lore.kernel.org/linux-doc/20200929212747.251804-1-jhubbard@nvidia.com/
[2] https://lore.kernel.org/r/CAHk-=wgh-TMPHLY3jueHX7Y2fWh3D+nMBqVS__AZm6-oorquWA@mail.gmail.com
This patch (of 9):
Rename nearly every "gup_benchmark" reference and file name to "gup_test".
The one exception is for the actual gup benchmark test itself.
The current code already does a *little* bit more than benchmarking, and
definitely covers more than get_user_pages_fast(). More importantly,
however, subsequent patches are about to add some functionality that is
non-benchmark related.
Closely related changes:
* Kconfig: in addition to renaming the options from GUP_BENCHMARK to
GUP_TEST, update the help text to reflect that it's no longer a
benchmark-only test.
Link: https://lkml.kernel.org/r/20201026064021.3545418-1-jhubbard@nvidia.com
Link: https://lkml.kernel.org/r/20201026064021.3545418-2-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The `else' is not useful after a `return' in __lock_page_or_retry().
[akpm@linux-foundation.org: coding style fixes]
Link: https://lkml.kernel.org/r/20201202154720.115162-1-carver4lio@163.com
Signed-off-by: Hailong Liu<liu.hailong6@zte.com.cn>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To fix a kernel-doc markups issue:
mm/truncate.c:646: warning: Function parameter or member 'mapping' not described in 'invalidate_mapping_pagevec'
mm/truncate.c:646: warning: Function parameter or member 'start' not described in 'invalidate_mapping_pagevec'
mm/truncate.c:646: warning: Function parameter or member 'end' not described in 'invalidate_mapping_pagevec'
mm/truncate.c:646: warning: Function parameter or member 'nr_pagevec' not described in 'invalidate_mapping_pagevec'
Link: https://lkml.kernel.org/r/1605605088-30668-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert generic_file_buffered_read() to get pages to read from in batches,
and then copy data to userspace from many pages at once - in particular,
we now don't touch any cachelines that might be contended while we're in
the loop to copy data to userspace.
This is is a performance improvement on workloads that do buffered reads
with large blocksizes, and a very large performance improvement if that
file is also being accessed concurrently by different threads.
On smaller reads (512 bytes), there's a very small performance improvement
(1%, within the margin of error).
akpm: kernel test robot found a 32% speedup on one test:
https://lkml.kernel.org/r/20201030081456.GY31092@shao2-debian
Link: https://lkml.kernel.org/r/20201025212949.602194-3-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "generic_file_buffered_read() improvements", v2.
generic_file_buffered_read() has turned into a real monstrosity to work
with. And it's a major performance improvement, for both small random and
large sequential reads. On my test box, 4k buffered random reads go from
~150k to ~250k iops, and the improvements to big sequential reads are even
bigger.
This incorporates the fix for IOCB_WAITQ handling that Jens just posted as
well, also factors out lock_page_for_iocb() to improve handling of the
various iocb flags.
This patch (of 2):
This is prep work for changing generic_file_buffered_read() to use
find_get_pages_contig() to batch up all the pagecache lookups.
This patch should be functionally identical to the existing code and
changes as little as of the flow control as possible. More refactoring
could be done, this patch is intended to be relatively minimal.
Link: https://lkml.kernel.org/r/20201025212949.602194-1-kent.overstreet@gmail.com
Link: https://lkml.kernel.org/r/20201025212949.602194-2-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Collect the time for each allocation recorded in page owner so that
allocation "surges" can be measured.
Record the pid for each allocation recorded in page owner so that the
source of allocation "surges" can be better identified.
The above is very useful when doing memory analysis. On a crash for
example, we can get this information from kdump (or ramdump) and parse it
to figure out memory allocation problems.
Please note that on x86_64 this increases the size of struct page_owner
from 16 bytes to 32.
Vlastimil: it's not a functionality intended for production, so unless
somebody says they need to enable page_owner for debugging and this
increase prevents them from fitting into available memory, let's not
complicate things with making this optional.
[lmark@codeaurora.org: v3]
Link: https://lkml.kernel.org/r/20201210160357.27779-1-georgi.djakov@linaro.org
Link: https://lkml.kernel.org/r/20201209125153.10533-1-georgi.djakov@linaro.org
Signed-off-by: Liam Mark <lmark@codeaurora.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
