Currently, memcg uses rstat to maintain aggregated hierarchical stats.
Counters are maintained for hierarchical stats at each memcg. Rstat
tracks which cgroups have updates on which cpus to keep those counters
fresh on the read-side.
Non-hierarchical stats are currently not covered by rstat. Their per-cpu
counters are summed up on every read, which is expensive. The original
implementation did the same. At some point before rstat, non-hierarchical
aggregated counters were introduced by commit a983b5ebee ("mm:
memcontrol: fix excessive complexity in memory.stat reporting"). However,
those counters were updated on the performance critical write-side, which
caused regressions, so they were later removed by commit 815744d751
("mm: memcontrol: don't batch updates of local VM stats and events"). See
[1] for more detailed history.
Kernel versions in between a983b5ebee & 815744d751 (a year and a half)
enjoyed cheap reads of non-hierarchical stats, specifically on cgroup v1.
When moving to more recent kernels, a performance regression for reading
non-hierarchical stats is observed.
Now that we have rstat, we know exactly which percpu counters have updates
for each stat. We can maintain non-hierarchical counters again, making
reads much more efficient, without affecting the performance critical
write-side. Hence, add non-hierarchical (i.e local) counters for the
stats, and extend rstat flushing to keep those up-to-date.
A caveat is that we now need a stats flush before reading
local/non-hierarchical stats through {memcg/lruvec}_page_state_local() or
memcg_events_local(), where we previously only needed a flush to read
hierarchical stats. Most contexts reading non-hierarchical stats are
already doing a flush, add a flush to the only missing context in
count_shadow_nodes().
With this patch, reading memory.stat from 1000 memcgs is 3x faster on a
machine with 256 cpus on cgroup v1:
# for i in $(seq 1000); do mkdir /sys/fs/cgroup/memory/cg$i; done
# time cat /sys/fs/cgroup/memory/cg*/memory.stat > /dev/null
real 0m0.125s
user 0m0.005s
sys 0m0.120s
After:
real 0m0.032s
user 0m0.005s
sys 0m0.027s
To make sure there are no regressions on cgroup v2, I ran an artificial
reclaim/refault stress test [2] that creates (NR_CPUS * 2) cgroups,
assigns them limits, runs a worker process in each cgroup that allocates
tmpfs memory equal to quadruple the limit (to invoke reclaim
continuously), and then reads back the entire file (to invoke refaults).
All workers are run in parallel, and zram is used as a swapping backend.
Both reclaim and refault have conditional stats flushing. I ran this on a
machine with 112 cpus, once on mm-unstable, and once on mm-unstable with
this patch reverted.
(1) A few runs without this patch:
# time ./stress_reclaim_refault.sh
real 0m9.949s
user 0m0.496s
sys 14m44.974s
# time ./stress_reclaim_refault.sh
real 0m10.049s
user 0m0.486s
sys 14m55.791s
# time ./stress_reclaim_refault.sh
real 0m9.984s
user 0m0.481s
sys 14m53.841s
(2) A few runs with this patch:
# time ./stress_reclaim_refault.sh
real 0m9.885s
user 0m0.486s
sys 14m48.753s
# time ./stress_reclaim_refault.sh
real 0m9.903s
user 0m0.495s
sys 14m48.339s
# time ./stress_reclaim_refault.sh
real 0m9.861s
user 0m0.507s
sys 14m49.317s
No regressions are observed with this patch. There is actually a very
slight improvement. If I have to guess, maybe it's because we avoid
the percpu loop in count_shadow_nodes() when calling
lruvec_page_state_local(), but I could not prove this using perf, it's
probably in the noise.
[1] https://lore.kernel.org/lkml/20230725201811.GA1231514@cmpxchg.org/
[2] https://lore.kernel.org/lkml/CAJD7tkb17x=qwoO37uxyYXLEUVp15BQKR+Xfh7Sg9Hx-wTQ_=w@mail.gmail.com/
Link: https://lkml.kernel.org/r/20230803185046.1385770-1-yosryahmed@google.com
Link: https://lkml.kernel.org/r/20230726153223.821757-2-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Enable handle_userfault to operate under VMA lock by releasing VMA lock
instead of mmap_lock and retrying. Note that FAULT_FLAG_RETRY_NOWAIT
should never be used when handling faults under per-VMA lock protection
because that would break the assumption that lock is dropped on retry.
[surenb@google.com: fix a lockdep issue in vma_assert_write_locked]
Link: https://lkml.kernel.org/r/20230712195652.969194-1-surenb@google.com
Link: https://lkml.kernel.org/r/20230630211957.1341547-7-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hillf Danton <hdanton@sina.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When page fault is handled under per-VMA lock protection, all swap page
faults are retried with mmap_lock because folio_lock_or_retry has to drop
and reacquire mmap_lock if folio could not be immediately locked. Follow
the same pattern as mmap_lock to drop per-VMA lock when waiting for folio
and retrying once folio is available.
With this obstacle removed, enable do_swap_page to operate under per-VMA
lock protection. Drivers implementing ops->migrate_to_ram might still
rely on mmap_lock, therefore we have to fall back to mmap_lock in that
particular case.
Note that the only time do_swap_page calls synchronous swap_readpage is
when SWP_SYNCHRONOUS_IO is set, which is only set for
QUEUE_FLAG_SYNCHRONOUS devices: brd, zram and nvdimms (both btt and pmem).
Therefore we don't sleep in this path, and there's no need to drop the
mmap or per-VMA lock.
Link: https://lkml.kernel.org/r/20230630211957.1341547-6-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Tested-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hillf Danton <hdanton@sina.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
handle_mm_fault returning VM_FAULT_RETRY or VM_FAULT_COMPLETED means
mmap_lock has been released. However with per-VMA locks behavior is
different and the caller should still release it. To make the rules
consistent for the caller, drop the per-VMA lock when returning
VM_FAULT_RETRY or VM_FAULT_COMPLETED. Currently the only path returning
VM_FAULT_RETRY under per-VMA locks is do_swap_page and no path returns
VM_FAULT_COMPLETED for now.
[willy@infradead.org: fix riscv]
Link: https://lkml.kernel.org/r/CAJuCfpE6GWEx1rPBmNpUfoD5o-gNFz9-UFywzCE2PbEGBiVz7g@mail.gmail.com
Link: https://lkml.kernel.org/r/20230630211957.1341547-4-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hillf Danton <hdanton@sina.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Per-VMA lock support for swap and userfaults", v7.
When per-VMA locks were introduced in [1] several types of page faults
would still fall back to mmap_lock to keep the patchset simple. Among
them are swap and userfault pages. The main reason for skipping those
cases was the fact that mmap_lock could be dropped while handling these
faults and that required additional logic to be implemented. Implement
the mechanism to allow per-VMA locks to be dropped for these cases.
First, change handle_mm_fault to drop per-VMA locks when returning
VM_FAULT_RETRY or VM_FAULT_COMPLETED to be consistent with the way
mmap_lock is handled. Then change folio_lock_or_retry to accept vm_fault
and return vm_fault_t which simplifies later patches. Finally allow swap
and uffd page faults to be handled under per-VMA locks by dropping per-VMA
and retrying, the same way it's done under mmap_lock. Naturally, once VMA
lock is dropped that VMA should be assumed unstable and can't be used.
This patch (of 6):
Commit [1] introduced IO polling support duding swapin to reduce swap read
latency for block devices that can be polled. However later commit [2]
removed polling support. Therefore it seems safe to remove do_poll
parameter in read_swap_cache_async and always call swap_readpage with
synchronous=false waiting for IO completion in folio_lock_or_retry.
[1] commit 23955622ff ("swap: add block io poll in swapin path")
[2] commit 9650b453a3 ("block: ignore RWF_HIPRI hint for sync dio")
Link: https://lkml.kernel.org/r/20230630211957.1341547-1-surenb@google.com
Link: https://lkml.kernel.org/r/20230630211957.1341547-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
put_ref_page() is not called to drop extra refcnt when comes from madvise
in the case pfn is valid but pgmap is NULL leading to page refcnt leak.
Link: https://lkml.kernel.org/r/20230701072837.1994253-1-linmiaohe@huawei.com
Fixes: 1e8aaedb18 ("mm,memory_failure: always pin the page in madvise_inject_error")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jann Horn demonstrated how userfaultfd ioctl UFFDIO_COPY into a private
shmem mapping can add valid PTEs to page table collapse_pte_mapped_thp()
thought it had emptied: page lock on the huge page is enough to protect
against WP faults (which find the PTE has been cleared), but not enough to
protect against userfaultfd. "BUG: Bad rss-counter state" followed.
retract_page_tables() protects against this by checking !vma->anon_vma;
but we know that MADV_COLLAPSE needs to be able to work on private shmem
mappings, even those with an anon_vma prepared for another part of the
mapping; and we know that MADV_COLLAPSE needs to work on shared shmem
mappings which are userfaultfd_armed(). Whether it needs to work on
private shmem mappings which are userfaultfd_armed(), I'm not so sure: but
assume that it does.
Just for this case, take the pmd_lock() two steps earlier: not because it
gives any protection against this case itself, but because ptlock nests
inside it, and it's the dropping of ptlock which let the bug in. In other
cases, continue to minimize the pmd_lock() hold time.
Link: https://lkml.kernel.org/r/4d31abf5-56c0-9f3d-d12f-c9317936691@google.com
Fixes: 1043173eb5 ("mm/khugepaged: collapse_pte_mapped_thp() with mmap_read_lock()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Jann Horn <jannh@google.com>
Closes: https://lore.kernel.org/linux-mm/CAG48ez0FxiRC4d3VTu_a9h=rg5FW-kYD5Rg5xo_RDBM0LTTqZQ@mail.gmail.com/
Acked-by: Peter Xu <peterx@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
hugetlb manually creates and destroys compound pages. As such it makes
assumptions about struct page layout. Commit ebc1baf5c9 ("mm: free up a
word in the first tail page") breaks hugetlb. The following will fix the
breakage.
Link: https://lkml.kernel.org/r/20230822231741.GC4509@monkey
Fixes: ebc1baf5c9 ("mm: free up a word in the first tail page")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
smaps_pte_hole_lookup() is calling shmem_partial_swap_usage() with page
table lock held: but shmem_partial_swap_usage() does cond_resched_rcu() if
need_resched(): "BUG: sleeping function called from invalid context".
Since shmem_partial_swap_usage() is designed to count across a range, but
smaps_pte_hole_lookup() only calls it for a single page slot, just break
out of the loop on the last or only page, before checking need_resched().
Link: https://lkml.kernel.org/r/6fe3b3ec-abdf-332f-5c23-6a3b3a3b11a9@google.com
Fixes: 2301003215 ("mm/smaps: simplify shmem handling of pte holes")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org> [5.16+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 98b211d641 ("madvise: convert madvise_free_pte_range() to use a
folio") replaced the page_mapcount() with folio_mapcount() to check
whether the folio is shared by other mapping.
It's not correct for large folios. folio_mapcount() returns the total
mapcount of large folio which is not suitable to detect whether the folio
is shared.
Use folio_estimated_sharers() which returns a estimated number of shares.
That means it's not 100% correct. It should be OK for madvise case here.
User-visible effects is that the THP is skipped when user call madvise.
But the correct behavior is THP should be split and processed then.
NOTE: this change is a temporary fix to reduce the user-visible effects
before the long term fix from David is ready.
Link: https://lkml.kernel.org/r/20230808020917.2230692-4-fengwei.yin@intel.com
Fixes: 98b211d641 ("madvise: convert madvise_free_pte_range() to use a folio")
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Reviewed-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit fc986a38b6 ("mm: huge_memory: convert madvise_free_huge_pmd to
use a folio") replaced the page_mapcount() with folio_mapcount() to check
whether the folio is shared by other mapping.
It's not correct for large folios. folio_mapcount() returns the total
mapcount of large folio which is not suitable to detect whether the folio
is shared.
Use folio_estimated_sharers() which returns a estimated number of shares.
That means it's not 100% correct. It should be OK for madvise case here.
User-visible effects is that the THP is skipped when user call madvise.
But the correct behavior is THP should be split and processed then.
NOTE: this change is a temporary fix to reduce the user-visible effects
before the long term fix from David is ready.
Link: https://lkml.kernel.org/r/20230808020917.2230692-3-fengwei.yin@intel.com
Fixes: fc986a38b6 ("mm: huge_memory: convert madvise_free_huge_pmd to use a folio")
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Reviewed-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "don't use mapcount() to check large folio sharing", v2.
In madvise_cold_or_pageout_pte_range() and madvise_free_pte_range(),
folio_mapcount() is used to check whether the folio is shared. But it's
not correct as folio_mapcount() returns total mapcount of large folio.
Use folio_estimated_sharers() here as the estimated number is enough.
This patchset will fix the cases:
User space application call madvise() with MADV_FREE, MADV_COLD and
MADV_PAGEOUT for specific address range. There are THP mapped to the
range. Without the patchset, the THP is skipped. With the patch, the
THP will be split and handled accordingly.
David reported the cow self test skip some cases because of MADV_PAGEOUT
skip THP:
https://lore.kernel.org/linux-mm/9e92e42d-488f-47db-ac9d-75b24cd0d037@intel.com/T/#mbf0f2ec7fbe45da47526de1d7036183981691e81
and I confirmed this patchset make it work again.
This patch (of 3):
Commit 07e8c82b5e ("madvise: convert madvise_cold_or_pageout_pte_range()
to use folios") replaced the page_mapcount() with folio_mapcount() to
check whether the folio is shared by other mapping.
It's not correct for large folio. folio_mapcount() returns the total
mapcount of large folio which is not suitable to detect whether the folio
is shared.
Use folio_estimated_sharers() which returns a estimated number of shares.
That means it's not 100% correct. It should be OK for madvise case here.
User-visible effects is that the THP is skipped when user call madvise.
But the correct behavior is THP should be split and processed then.
NOTE: this change is a temporary fix to reduce the user-visible effects
before the long term fix from David is ready.
Link: https://lkml.kernel.org/r/20230808020917.2230692-1-fengwei.yin@intel.com
Link: https://lkml.kernel.org/r/20230808020917.2230692-2-fengwei.yin@intel.com
Fixes: 07e8c82b5e ("madvise: convert madvise_cold_or_pageout_pte_range() to use folios")
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Reviewed-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replaces five calls to compound_head with one.
Link: https://lkml.kernel.org/r/20230816151201.3655946-14-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This function is misleading; people think it means "Is this a THP", when
all it actually does is check whether this is a large folio. Remove it;
the one remaining user should have been checking to see whether the folio
is PMD sized or not.
Link: https://lkml.kernel.org/r/20230816151201.3655946-12-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Store the folio order in the low byte of the flags word in the first tail
page. This frees up the word that was being used to store the order and
dtor bytes previously.
Link: https://lkml.kernel.org/r/20230816151201.3655946-11-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stored in the first tail page's flags, this flag replaces the destructor.
That removes the last of the destructors, so remove all references to
folio_dtor and compound_dtor.
Link: https://lkml.kernel.org/r/20230816151201.3655946-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We can use a bit in page[1].flags to indicate that this folio belongs to
hugetlb instead of using a value in page[1].dtors. That lets
folio_test_hugetlb() become an inline function like it should be. We can
also get rid of NULL_COMPOUND_DTOR.
Link: https://lkml.kernel.org/r/20230816151201.3655946-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The only remaining destructor is free_compound_page(). Inline it into
destroy_large_folio() and remove the array it used to live in.
Link: https://lkml.kernel.org/r/20230816151201.3655946-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Match folio_undo_large_rmappable(), and move the casting from page to
folio into the callers (which they were largely doing anyway).
Link: https://lkml.kernel.org/r/20230816151201.3655946-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Indirect calls are expensive, thanks to Spectre. Test for
TRANSHUGE_PAGE_DTOR and destroy the folio appropriately. Move the
free_compound_page() call into destroy_large_folio() to simplify later
patches.
Link: https://lkml.kernel.org/r/20230816151201.3655946-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pass a folio instead of the head page to save a few instructions. Update
the documentation, at least in English.
Link: https://lkml.kernel.org/r/20230816151201.3655946-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Indirect calls are expensive, thanks to Spectre. Call free_huge_page()
directly if the folio belongs to hugetlb.
Link: https://lkml.kernel.org/r/20230816151201.3655946-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 0b9d705297 ("mm: numa: Support NUMA hinting page faults from
gup/gup_fast") from 2012 documented as the primary reason why we would want
to handle NUMA hinting faults from GUP:
KVM secondary MMU page faults will trigger the NUMA hinting page
faults through gup_fast -> get_user_pages -> follow_page ->
handle_mm_fault.
That is still the case today, and relevant KVM code has been converted to
manually set FOLL_HONOR_NUMA_FAULT. So let's stop setting
FOLL_HONOR_NUMA_FAULT for all GUP users and cross fingers that not that
many other ones that really require such handling for autonuma remain.
Possible interaction with MMU notifiers:
Assume a driver obtains a page using get_user_pages() to map it into
a secondary MMU, and uses the MMU notifier framework to get notified on
changes.
Assume get_user_pages() succeeded on a PROT_NONE-mapped page (because
FOLL_HONOR_NUMA_FAULT is not set) in an accessible VMA and the page is
mapped into a secondary MMU. Once user space would turn that mapping
inaccessible using mprotect(PROT_NONE), the actual PTE in the page table
might not change. If the MMU notifier would be smart and optimize for that
case "why notify if the PTE didn't change", that could be problematic.
At least change_pmd_range() with MMU_NOTIFY_PROTECTION_VMA for now does an
unconditional mmu_notifier_invalidate_range_start() ->
mmu_notifier_invalidate_range_end() and should be fine.
Note that even if a PTE in an accessible VMA is pte_protnone(), the
underlying page might be accessed by a secondary MMU that does not set
FOLL_HONOR_NUMA_FAULT, and test_young() MMU notifiers would return "true".
Link: https://lkml.kernel.org/r/20230803143208.383663-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: liubo <liubo254@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The old name is confusing because it implies the completion of earlier
kmemleak_init(), the new name update to kmemleak_late_initial represents
the completion of kmemleak_late_init().
No functional changes.
Link: https://lkml.kernel.org/r/20230815144128.3623103-3-xiaolei.wang@windriver.com
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/kmemleak: use object_cache instead of
kmemleak_initialized", v3.
Use object_cache instead of kmemleak_initialized to check in
set_track_prepare(), so that memory leaks after kmemleak_init() can be
recorded and Rename kmemleak_initialized to kmemleak_late_initialized
unreferenced object 0xc674ca80 (size 64):
comm "swapper/0", pid 1, jiffies 4294938337 (age 204.880s)
hex dump (first 32 bytes):
80 55 75 c6 80 54 75 c6 00 55 75 c6 80 52 75 c6 .Uu..Tu..Uu..Ru.
00 53 75 c6 00 00 00 00 00 00 00 00 00 00 00 00 .Su..........
This patch (of 2):
kmemleak_initialized is set in kmemleak_late_init(), which also means that
there is no call trace which object's memory leak is before
kmemleak_late_init(), so use object_cache instead of kmemleak_initialized
to check in set_track_prepare() to avoid no call trace records when there
is a memory leak in the code between kmemleak_init() and
kmemleak_late_init().
unreferenced object 0xc674ca80 (size 64):
comm "swapper/0", pid 1, jiffies 4294938337 (age 204.880s)
hex dump (first 32 bytes):
80 55 75 c6 80 54 75 c6 00 55 75 c6 80 52 75 c6 .Uu..Tu..Uu..Ru.
00 53 75 c6 00 00 00 00 00 00 00 00 00 00 00 00 .Su..........
Link: https://lkml.kernel.org/r/20230815144128.3623103-1-xiaolei.wang@windriver.com
Link: https://lkml.kernel.org/r/20230815144128.3623103-2-xiaolei.wang@windriver.com
Fixes: 56a61617dd ("mm: use stack_depot for recording kmemleak's backtrace")
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
ksm currently maintains several statistics, which let you determine how
successful KSM is at sharing pages. However it does not contain a metric
to determine how much work it does.
This commit adds the pages scanned metric. This allows the administrator
to determine how many pages have been scanned over a period of time.
Link: https://lkml.kernel.org/r/20230811193655.2518943-1-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
By making maybe_unlock_mmap_for_io() handle the VMA lock correctly, we
make fault_dirty_shared_page() safe to be called without the mmap lock
held.
Link: https://lkml.kernel.org/r/20230812002033.1002367-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: David Hildenbrand <david@redhat.com>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Saves four implicit call to compound_head().
Link: https://lkml.kernel.org/r/20230812062612.3184990-1-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm,thp: fix sloppy text output".
Three independent trivial patches, fixing sloppy text output which has
annoyed me; but might risk surprising a parser, so any can be dropped.
This patch (of 3):
The SysRq-m or OOM Mem-Info dmesg showed (long lines containing) ...
shmem:NkB shmem_thp: NkB shmem_pmdmapped: NkB anon_thp: NkB ...
Delete the space after the colon after shmem_thp, shmem_pmdmapped,
anon_thp: as the shmem example shows, no other fields have a space after
the colon in this output.
Link: https://lkml.kernel.org/r/dc264fd6-40bb-6510-db36-9340a5f01d94@google.com
Link: https://lkml.kernel.org/r/c1edd7da-5493-c542-6feb-92452b4dab3b@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This sysctl has the very unusual behaviour of not allowing any user (even
CAP_SYS_ADMIN) to reduce the restriction setting, meaning that if you were
to set this sysctl to a more restrictive option in the host pidns you
would need to reboot your machine in order to reset it.
The justification given in [1] is that this is a security feature and thus
it should not be possible to disable. Aside from the fact that we have
plenty of security-related sysctls that can be disabled after being
enabled (fs.protected_symlinks for instance), the protection provided by
the sysctl is to stop users from being able to create a binary and then
execute it. A user with CAP_SYS_ADMIN can trivially do this without
memfd_create(2):
% cat mount-memfd.c
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <linux/mount.h>
#define SHELLCODE "#!/bin/echo this file was executed from this totally private tmpfs:"
int main(void)
{
int fsfd = fsopen("tmpfs", FSOPEN_CLOEXEC);
assert(fsfd >= 0);
assert(!fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 2));
int dfd = fsmount(fsfd, FSMOUNT_CLOEXEC, 0);
assert(dfd >= 0);
int execfd = openat(dfd, "exe", O_CREAT | O_RDWR | O_CLOEXEC, 0782);
assert(execfd >= 0);
assert(write(execfd, SHELLCODE, strlen(SHELLCODE)) == strlen(SHELLCODE));
assert(!close(execfd));
char *execpath = NULL;
char *argv[] = { "bad-exe", NULL }, *envp[] = { NULL };
execfd = openat(dfd, "exe", O_PATH | O_CLOEXEC);
assert(execfd >= 0);
assert(asprintf(&execpath, "/proc/self/fd/%d", execfd) > 0);
assert(!execve(execpath, argv, envp));
}
% ./mount-memfd
this file was executed from this totally private tmpfs: /proc/self/fd/5
%
Given that it is possible for CAP_SYS_ADMIN users to create executable
binaries without memfd_create(2) and without touching the host filesystem
(not to mention the many other things a CAP_SYS_ADMIN process would be
able to do that would be equivalent or worse), it seems strange to cause a
fair amount of headache to admins when there doesn't appear to be an
actual security benefit to blocking this. There appear to be concerns
about confused-deputy-esque attacks[2] but a confused deputy that can
write to arbitrary sysctls is a bigger security issue than executable
memfds.
/* New API */
The primary requirement from the original author appears to be more based
on the need to be able to restrict an entire system in a hierarchical
manner[3], such that child namespaces cannot re-enable executable memfds.
So, implement that behaviour explicitly -- the vm.memfd_noexec scope is
evaluated up the pidns tree to &init_pid_ns and you have the most
restrictive value applied to you. The new lower limit you can set
vm.memfd_noexec is whatever limit applies to your parent.
Note that a pidns will inherit a copy of the parent pidns's effective
vm.memfd_noexec setting at unshare() time. This matches the existing
behaviour, and it also ensures that a pidns will never have its
vm.memfd_noexec setting *lowered* behind its back (but it will be raised
if the parent raises theirs).
/* Backwards Compatibility */
As the previous version of the sysctl didn't allow you to lower the
setting at all, there are no backwards compatibility issues with this
aspect of the change.
However it should be noted that now that the setting is completely
hierarchical. Previously, a cloned pidns would just copy the current
pidns setting, meaning that if the parent's vm.memfd_noexec was changed it
wouldn't propoagate to existing pid namespaces. Now, the restriction
applies recursively. This is a uAPI change, however:
* The sysctl is very new, having been merged in 6.3.
* Several aspects of the sysctl were broken up until this patchset and
the other patchset by Jeff Xu last month.
And thus it seems incredibly unlikely that any real users would run into
this issue. In the worst case, if this causes userspace isues we could
make it so that modifying the setting follows the hierarchical rules but
the restriction checking uses the cached copy.
[1]: https://lore.kernel.org/CABi2SkWnAgHK1i6iqSqPMYuNEhtHBkO8jUuCvmG3RmUB5TKHJw@mail.gmail.com/
[2]: https://lore.kernel.org/CALmYWFs_dNCzw_pW1yRAo4bGCPEtykroEQaowNULp7svwMLjOg@mail.gmail.com/
[3]: https://lore.kernel.org/CALmYWFuahdUF7cT4cm7_TGLqPanuHXJ-hVSfZt7vpTnc18DPrw@mail.gmail.com/
Link: https://lkml.kernel.org/r/20230814-memfd-vm-noexec-uapi-fixes-v2-4-7ff9e3e10ba6@cyphar.com
Fixes: 105ff5339f ("mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Daniel Verkamp <dverkamp@chromium.org>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In order to incentivise userspace to switch to passing MFD_EXEC and
MFD_NOEXEC_SEAL, we need to provide a warning on each attempt to call
memfd_create() without the new flags. pr_warn_once() is not useful
because on most systems the one warning is burned up during the boot
process (on my system, systemd does this within the first second of boot)
and thus userspace will in practice never see the warnings to push them to
switch to the new flags.
The original patchset[1] used pr_warn_ratelimited(), however there were
concerns about the degree of spam in the kernel log[2,3]. The resulting
inability to detect every case was flagged as an issue at the time[4].
While we could come up with an alternative rate-limiting scheme such as
only outputting the message if vm.memfd_noexec has been modified, or only
outputting the message once for a given task, these alternatives have
downsides that don't make sense given how low-stakes a single kernel
warning message is. Switching to pr_info_ratelimited() instead should be
fine -- it's possible some monitoring tool will be unhappy with a stream
of warning-level messages but there's already plenty of info-level message
spam in dmesg.
[1]: https://lore.kernel.org/20221215001205.51969-4-jeffxu@google.com/
[2]: https://lore.kernel.org/202212161233.85C9783FB@keescook/
[3]: https://lore.kernel.org/Y5yS8wCnuYGLHMj4@x1n/
[4]: https://lore.kernel.org/f185bb42-b29c-977e-312e-3349eea15383@linuxfoundation.org/
Link: https://lkml.kernel.org/r/20230814-memfd-vm-noexec-uapi-fixes-v2-3-7ff9e3e10ba6@cyphar.com
Fixes: 105ff5339f ("mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Daniel Verkamp <dverkamp@chromium.org>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Given the difficulty of auditing all of userspace to figure out whether
every memfd_create() user has switched to passing MFD_EXEC and
MFD_NOEXEC_SEAL flags, it seems far less distruptive to make it possible
for older programs that don't make use of executable memfds to run under
vm.memfd_noexec=2. Otherwise, a small dependency change can result in
spurious errors. For programs that don't use executable memfds, passing
MFD_NOEXEC_SEAL is functionally a no-op and thus having the same
In addition, every failure under vm.memfd_noexec=2 needs to print to the
kernel log so that userspace can figure out where the error came from.
The concerns about pr_warn_ratelimited() spam that caused the switch to
pr_warn_once()[1,2] do not apply to the vm.memfd_noexec=2 case.
This is a user-visible API change, but as it allows programs to do
something that would be blocked before, and the sysctl itself was broken
and recently released, it seems unlikely this will cause any issues.
[1]: https://lore.kernel.org/Y5yS8wCnuYGLHMj4@x1n/
[2]: https://lore.kernel.org/202212161233.85C9783FB@keescook/
Link: https://lkml.kernel.org/r/20230814-memfd-vm-noexec-uapi-fixes-v2-2-7ff9e3e10ba6@cyphar.com
Fixes: 105ff5339f ("mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Daniel Verkamp <dverkamp@chromium.org>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since commit e774a7bc7f ("mm: zswap: remove page reclaim logic from
z3fold"), zpool and zpool_ops have been removed, so also remove the
corresponding comments.
Link: https://lkml.kernel.org/r/20230814221142.486548-1-xiujianfeng@huaweicloud.com
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We have get_pageblock_migratetype and get_pfnblock_migratetype to get
migratetype of page. get_pfnblock_migratetype accepts both page and pfn
from caller while get_pageblock_migratetype only accept page and get pfn
with page_to_pfn from page.
In case we already record pfn of page, we can simply call
get_pfnblock_migratetype to avoid a page_to_pfn.
Link: https://lkml.kernel.org/r/20230811115945.3423894-3-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Two minor cleanups for get pageblock migratetype".
This series contains two minor cleanups for get pageblock migratetype.
More details can be found in respective patches.
This patch (of 2):
get_pfnblock_flags_mask() just calls inline inner
__get_pfnblock_flags_mask without any extra work. Just opencode
__get_pfnblock_flags_mask in get_pfnblock_flags_mask and replace call to
__get_pfnblock_flags_mask with call to get_pfnblock_flags_mask to remove
unnecessary __get_pfnblock_flags_mask.
Link: https://lkml.kernel.org/r/20230811115945.3423894-1-shikemeng@huaweicloud.com
Link: https://lkml.kernel.org/r/20230811115945.3423894-2-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Just remove the redundant parameter alloc_order from
reserve_highatomic_pageblock(). No functional modification involved.
Link: https://lkml.kernel.org/r/20230809073323.1065286-1-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This patch is based on the commit 5da226dbfce3("mm: skip CMA pages when
they are not available") which skips cma pages reclaim when they are not
eligible for the current allocation context. In mglru, such pages are
added to the tail of the immediate generation to maintain better LRU
order, which is unlike the case of conventional LRU where such pages are
directly added to the head of the LRU list(akin to adding to head of the
youngest generation in mglru).
No observable issue without this patch on MGLRU, but logically it make
sense to skip the CMA page reclaim when those pages can't be satisfied for
the current allocation context.
Link: https://lkml.kernel.org/r/1691568344-13475-1-git-send-email-quic_charante@quicinc.com
Fixes: ac35a49023 ("mm: multi-gen LRU: minimal implementation")
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Reviewed-by: Kalesh Singh <kaleshsingh@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Parameter pgdat is not used in fragmentation_score_wmark. Just remove it.
Link: https://lkml.kernel.org/r/20230809094910.3092446-1-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We get batch from pcp and just pass it to nr_pcp_free immediately. Get
batch from pcp inside nr_pcp_free to remove unnecessary parameter batch.
Link: https://lkml.kernel.org/r/20230809100754.3094517-3-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Two minor cleanups for pcp list in page_alloc".
There are two minor cleanups for pcp list in page_alloc. More details
can be found in respective patches.
This patch (of 2):
After commit fd56eef258 ("mm/page_alloc: simplify how many pages are
selected per pcp list during bulk free"), we will drain all pages in
selected pcp list. And we ensured passed count is < pcp->count. Then,
the search will finish before wrap-around and track of active PCP lists
range intended for wrap-around case is no longer needed.
Link: https://lkml.kernel.org/r/20230809100754.3094517-1-shikemeng@huaweicloud.com
Link: https://lkml.kernel.org/r/20230809100754.3094517-2-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With memmap on memory, some architecture needs more details w.r.t altmap
such as base_pfn, end_pfn, etc to unmap vmemmap memory. Instead of
computing them again when we remove a memory block, embed vmem_altmap
details in struct memory_block if we are using memmap on memory block
feature.
[yangyingliang@huawei.com: fix error return code in add_memory_resource()]
Link: https://lkml.kernel.org/r/20230809081552.1351184-1-yangyingliang@huawei.com
Link: https://lkml.kernel.org/r/20230808091501.287660-7-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently, memmap_on_memory feature is only supported with memory block
sizes that result in vmemmap pages covering full page blocks. This is
because memory onlining/offlining code requires applicable ranges to be
pageblock-aligned, for example, to set the migratetypes properly.
This patch helps to lift that restriction by reserving more pages than
required for vmemmap space. This helps the start address to be page block
aligned with different memory block sizes. Using this facility implies
the kernel will be reserving some pages for every memoryblock. This
allows the memmap on memory feature to be widely useful with different
memory block size values.
For ex: with 64K page size and 256MiB memory block size, we require 4
pages to map vmemmap pages, To align things correctly we end up adding a
reserve of 28 pages. ie, for every 4096 pages 28 pages get reserved.
Link: https://lkml.kernel.org/r/20230808091501.287660-5-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Some architectures would want different restrictions. Hence add an
architecture-specific override.
The PMD_SIZE check is moved there.
Link: https://lkml.kernel.org/r/20230808091501.287660-4-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If not supported, fallback to not using memap on memmory. This avoids
the need for callers to do the fallback.
Link: https://lkml.kernel.org/r/20230808091501.287660-3-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
