linux/mm
Hugh Dickins 1e6decf30a shmem: shmem_writepage() split unlikely i915 THP
drivers/gpu/drm/i915/gem/i915_gem_shmem.c contains a shmem_writeback()
which calls shmem_writepage() from a shrinker: that usually works well
enough; but if /sys/kernel/mm/transparent_hugepage/shmem_enabled has been
set to "always" (intended to be usable) or "force" (forces huge everywhere
for easy testing), shmem_writepage() is surprised to be called with a huge
page, and crashes on the VM_BUG_ON_PAGE(PageCompound) (I did not find out
where the crash happens when CONFIG_DEBUG_VM is off).

LRU page reclaim always splits the shmem huge page first: I'd prefer not
to demand that of i915, so check and split compound in shmem_writepage().

Patch history: when first sent last year
http://lkml.kernel.org/r/alpine.LSU.2.11.2008301401390.5954@eggly.anvils
https://lore.kernel.org/linux-mm/20200919042009.bomzxmrg7%25akpm@linux-foundation.org/
Matthew Wilcox noticed that tail pages were wrongly left clean.  This
version brackets the split with Set and Clear PageDirty as he suggested:
which works very well, even if it falls short of our aspirations.  And
recently I realized that the crash is not limited to the testing option
"force", but affects "always" too: which is more important to fix.

Link: https://lkml.kernel.org/r/bac6158c-8b3d-4dca-cffc-4982f58d9794@google.com
Fixes: 2d6692e642 ("drm/i915: Start writeback from the shrinker")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:12 -07:00
..
kasan kasan: add memzero init for unaligned size at DEBUG 2021-07-15 10:13:49 -07:00
kfence kfence: skip all GFP_ZONEMASK allocations 2021-07-23 17:43:28 -07:00
backing-dev.c writeback: fix bandwidth estimate for spiky workload 2021-09-03 09:58:10 -07:00
balloon_compaction.c mm: fix typos in comments 2021-05-07 00:26:35 -07:00
bootmem_info.c mm: memory_hotplug: factor out bootmem core functions to bootmem_info.c 2021-06-30 20:47:25 -07:00
cleancache.c
cma.c mm: use proper type for cma_[alloc|release] 2021-05-05 11:27:24 -07:00
cma.h mm: cma: support sysfs 2021-05-05 11:27:24 -07:00
cma_debug.c mm/cma: change cma mutex to irq safe spinlock 2021-05-05 11:27:21 -07:00
cma_sysfs.c mm: cma: support sysfs 2021-05-05 11:27:24 -07:00
compaction.c Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
debug.c mm/debug: factor PagePoisoned out of __dump_page 2021-06-29 10:53:53 -07:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable: fix corrupted page flag 2021-09-03 09:58:10 -07:00
dmapool.c mm/dmapool: use DEVICE_ATTR_RO macro 2021-06-29 10:53:52 -07:00
early_ioremap.c mm/early_ioremap.c: use __func__ instead of function name 2021-02-26 09:41:02 -08:00
fadvise.c mm, fadvise: improve the expensive remote LRU cache draining after FADV_DONTNEED 2020-10-13 18:38:29 -07:00
failslab.c
filemap.c mm: remove irqsave/restore locking from contexts with irqs enabled 2021-09-03 09:58:10 -07:00
frontswap.c mm/mempool: minor coding style tweaks 2021-05-05 11:27:27 -07:00
gup.c mm/gup: remove try_get_page(), call try_get_compound_head() directly 2021-09-03 09:58:11 -07:00
gup_test.c selftests/vm: gup_test: test faulting in kernel, and verify pinnable pages 2021-05-05 11:27:26 -07:00
gup_test.h selftests/vm: gup_test: fix test flag 2021-05-05 11:27:26 -07:00
highmem.c mm: fix typos in comments 2021-05-07 00:26:35 -07:00
hmm.c mm: device exclusive memory access 2021-07-01 11:06:03 -07:00
huge_memory.c huge tmpfs: fix split_huge_page() after FALLOC_FL_KEEP_SIZE 2021-09-03 09:58:11 -07:00
hugetlb.c hugetlb: don't pass page cache pages to restore_reserve_on_error 2021-08-20 11:31:42 -07:00
hugetlb_cgroup.c hugetlb: make free_huge_page irq safe 2021-05-05 11:27:22 -07:00
hugetlb_vmemmap.c mm: hugetlb: introduce CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON 2021-06-30 20:47:26 -07:00
hugetlb_vmemmap.h mm: hugetlb: introduce nr_free_vmemmap_pages in the struct hstate 2021-06-30 20:47:25 -07:00
hwpoison-inject.c mm,hwpoison-inject: don't pin for hwpoison_filter 2020-10-16 11:11:16 -07:00
init-mm.c mm: add setup_initial_init_mm() helper 2021-07-08 11:48:21 -07:00
internal.h mmap: make mlock_future_check() global 2021-07-08 11:48:20 -07:00
interval_tree.c mm/interval_tree: add comments to improve code readability 2021-04-30 11:20:38 -07:00
io-mapping.c mm: add a io_mapping_map_user helper 2021-04-30 11:20:39 -07:00
ioremap.c mm/ioremap: fix iomap_max_page_shift 2021-05-14 19:41:32 -07:00
Kconfig mm: introduce memfd_secret system call to create "secret" memory areas 2021-07-08 11:48:21 -07:00
Kconfig.debug mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO 2020-12-15 12:13:46 -08:00
khugepaged.c huge tmpfs: SGP_NOALLOC to stop collapse_file() on race 2021-09-03 09:58:12 -07:00
kmemleak.c kasan, kmemleak: reset tags when scanning block 2021-08-13 14:09:31 -10:00
ksm.c mm/ksm: use vma_lookup() in find_mergeable_vma() 2021-06-29 10:53:52 -07:00
list_lru.c mm: vmscan: consolidate shrinker_maps handling code 2021-05-05 11:27:23 -07:00
maccess.c
madvise.c mm/madvise: report SIGBUS as -EFAULT for MADV_POPULATE_(READ|WRITE) 2021-08-13 14:09:31 -10:00
Makefile mm: introduce memfd_secret system call to create "secret" memory areas 2021-07-08 11:48:21 -07:00
mapping_dirty_helpers.c mm/mapping_dirty_helpers: remove double Note in kerneldoc 2021-07-01 11:06:02 -07:00
memblock.c memblock: make for_each_mem_range() traverse MEMBLOCK_HOTPLUG regions 2021-07-23 17:43:28 -07:00
memcontrol.c writeback: memcg: simplify cgroup_writeback_by_id 2021-09-03 09:58:10 -07:00
memfd.c Reimplement RLIMIT_MEMLOCK on top of ucounts 2021-04-30 14:14:02 -05:00
memory-failure.c mm/hwpoison: retry with shake_page() for unhandlable pages 2021-08-20 11:31:42 -07:00
memory.c mm: fix the deadlock in finish_fault() 2021-07-23 17:43:28 -07:00
memory_hotplug.c mm/memory_hotplug: fix potential permanent lru cache disable 2021-08-25 12:25:12 -07:00
mempolicy.c mm/mempolicy: use unified 'nodes' for bind/interleave/prefer policies 2021-06-30 20:47:29 -07:00
mempool.c kasan: use separate (un)poison implementation for integrated init 2021-06-04 19:32:21 +01:00
memremap.c mm/memremap.c: fix improper SPDX comment style 2021-04-30 11:20:37 -07:00
memtest.c
migrate.c mm/migrate: fix NR_ISOLATED corruption on 64-bit 2021-07-30 10:14:39 -07:00
mincore.c inode: make init and permission helpers idmapped mount aware 2021-01-24 14:27:16 +01:00
mlock.c mm: introduce memfd_secret system call to create "secret" memory areas 2021-07-08 11:48:21 -07:00
mm_init.c include/linux/page-flags-layout.h: cleanups 2021-04-30 11:20:42 -07:00
mmap.c mmap: make mlock_future_check() global 2021-07-08 11:48:20 -07:00
mmap_lock.c mm: mmap_lock: fix disabling preemption directly 2021-07-23 17:43:28 -07:00
mmu_gather.c mm: eliminate "expecting prototype" kernel-doc warnings 2021-04-16 16:10:36 -07:00
mmu_notifier.c mm/mmu_notifiers: ensure range_end() is paired with range_start() 2021-03-25 09:22:55 -07:00
mmzone.c mm/lru: replace pgdat lru_lock with lruvec lock 2020-12-15 14:48:04 -08:00
mprotect.c mm: device exclusive memory access 2021-07-01 11:06:03 -07:00
mremap.c mm/mremap: allow arch runtime override 2021-07-08 11:48:23 -07:00
msync.c mm/msync: exit early when the flags is an MS_ASYNC and start < vm_start 2021-04-30 11:20:37 -07:00
nommu.c mm/nommu: unexport do_munmap() 2021-06-30 20:47:30 -07:00
oom_kill.c Merge branch 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu 2021-07-04 12:58:33 -07:00
page-writeback.c writeback: use READ_ONCE for unlocked reads of writeback stats 2021-09-03 09:58:10 -07:00
page_alloc.c mm: add kernel_misc_reclaimable in show_free_areas 2021-09-03 09:58:10 -07:00
page_counter.c mm: page_counter: mitigate consequences of a page_counter underflow 2021-04-30 11:20:38 -07:00
page_ext.c mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM 2021-06-29 10:53:55 -07:00
page_idle.c mm: page_idle_get_page() does not need lru_lock 2020-12-15 14:48:03 -08:00
page_io.c swap: fix swapfile read/write offset 2021-03-02 17:25:46 -07:00
page_isolation.c mm/page_isolation: do not isolate the max order page 2020-12-15 12:13:45 -08:00
page_owner.c mm/page_owner: constify dump_page_owner 2021-06-29 10:53:53 -07:00
page_poison.c mm: page_poison: print page info when corruption is caught 2021-04-30 11:20:36 -07:00
page_reporting.c mm/page_reporting: allow driver to specify reporting order 2021-06-29 10:53:47 -07:00
page_reporting.h mm/page_reporting: export reporting order as module parameter 2021-06-29 10:53:47 -07:00
page_vma_mapped.c mm: device exclusive memory access 2021-07-01 11:06:03 -07:00
pagewalk.c mm: pagewalk: fix walk for hugepage tables 2021-06-29 10:53:49 -07:00
percpu-internal.h Merge branch 'for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu 2021-07-01 17:17:24 -07:00
percpu-km.c percpu: flush tlb in pcpu_reclaim_populated() 2021-07-04 18:30:17 +00:00
percpu-stats.c percpu: rework memcg accounting 2021-06-05 20:43:15 +00:00
percpu-vm.c percpu: flush tlb in pcpu_reclaim_populated() 2021-07-04 18:30:17 +00:00
percpu.c percpu: flush tlb in pcpu_reclaim_populated() 2021-07-04 18:30:17 +00:00
pgalloc-track.h mm: fix typos in comments 2021-05-07 00:26:35 -07:00
pgtable-generic.c mm/thp: fix __split_huge_pmd_locked() on shmem migration entry 2021-06-16 09:24:42 -07:00
process_vm_access.c mm/process_vm_access.c: remove duplicate include 2021-05-05 11:27:27 -07:00
ptdump.c mm: ptdump: fix build failure 2021-04-16 16:10:37 -07:00
readahead.c mm: Implement readahead_control pageset expansion 2021-04-23 10:14:29 +01:00
rmap.c mm/rmap: fix munlocking Anon THP with mlocked ptes 2021-07-12 11:30:56 -07:00
rodata_test.c mm/rodata_test.c: fix missing function declaration 2020-08-21 09:52:53 -07:00
secretmem.c mm/secretmem: wire up ->set_page_dirty 2021-07-23 17:43:28 -07:00
shmem.c shmem: shmem_writepage() split unlikely i915 THP 2021-09-03 09:58:12 -07:00
shuffle.c mm: eliminate "expecting prototype" kernel-doc warnings 2021-04-16 16:10:36 -07:00
shuffle.h mm/shuffle: fix section mismatch warning 2021-05-22 15:09:07 -10:00
slab.c mm: fix typos in comments 2021-05-07 00:26:35 -07:00
slab.h mm/memcg: fix NULL pointer dereference in memcg_slab_free_hook() 2021-07-30 10:14:39 -07:00
slab_common.c Merge branch 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu 2021-07-04 12:58:33 -07:00
slob.c mm: Don't build mm_dump_obj() on CONFIG_PRINTK=n kernels 2021-03-08 14:18:46 -08:00
slub.c mm: slub: fix slub_debug disabling for list of slabs 2021-08-13 14:09:31 -10:00
sparse-vmemmap.c mm: sparsemem: split the huge PMD mapping of vmemmap pages 2021-06-30 20:47:26 -07:00
sparse.c mm: memory_hotplug: factor out bootmem core functions to bootmem_info.c 2021-06-30 20:47:25 -07:00
swap.c mm: delete unused get_kernel_page() 2021-09-03 09:58:11 -07:00
swap_cgroup.c
swap_slots.c mm/swap_slots.c: delete meaningless forward declarations 2021-06-29 10:53:49 -07:00
swap_state.c Revert "mm: swap: check if swap backing device is congested or not" 2021-08-20 11:31:42 -07:00
swapfile.c fs, mm: fix race in unlinking swapfile 2021-09-03 09:58:11 -07:00
truncate.c fs: inode: count invalidated shadow pages in pginodesteal 2021-09-03 09:58:10 -07:00
usercopy.c
userfaultfd.c userfaultfd/shmem: modify shmem_mfill_atomic_pte to use install_pte() 2021-06-30 20:47:27 -07:00
util.c mm: Make copy_huge_page() always available 2021-07-12 11:30:56 -07:00
vmacache.c
vmalloc.c mm/vmalloc: include header for prototype of set_iounmap_nonlazy 2021-07-01 11:06:02 -07:00
vmpressure.c
vmscan.c mm: remove irqsave/restore locking from contexts with irqs enabled 2021-09-03 09:58:10 -07:00
vmstat.c mm/vmstat: inline NUMA event counter updates 2021-06-29 10:53:54 -07:00
workingset.c mm: workingset: define macro WORKINGSET_SHIFT 2021-06-30 20:47:28 -07:00
z3fold.c mm/z3fold: add kerneldoc fields for z3fold_pool 2021-07-01 11:06:03 -07:00
zbud.c mm/zbud: add kerneldoc fields for zbud_pool 2021-07-01 11:06:03 -07:00
zpool.c mm: fix typos in comments 2021-05-07 00:26:35 -07:00
zsmalloc.c mm/zsmalloc.c: improve readability for async_free_zspage() 2021-07-01 11:06:02 -07:00
zswap.c mm/zswap.c: fix two bugs in zswap_writeback_entry() 2021-06-30 20:47:31 -07:00