linux/mm
Andrea Arcangeli 2da28bfd96 thp: fix page_referenced to modify mapcount/vm_flags only if page is found
When vmscan.c calls page_referenced(), if an anon page was created
before a process forked, rmap will search for it in both of the
processes, even though one of them might have since broken COW.

If the child process mlocks the vma where the COWed page belongs to,
page_referenced() running on the page mapped by the parent would lead to
*vm_flags getting VM_LOCKED set erroneously (leading to the references
on the parent page being ignored and evicting the parent page too
early).

*mapcount would also be decremented by page_referenced_one even if the
page wasn't found by page_check_address.

This also lets pmdp_clear_flush_young_notify() go ahead on a
pmd_trans_splitting() pmd.

We hold the page_table_lock so __split_huge_page_map() must wait the
pmdp_clear_flush_young_notify() to complete before it can modify the
pmd.  The pmd is also still mapped in userland so the young bit may
materialize through a tlb miss before split_huge_page_map runs.

This will provide a more accurate page_referenced() behavior during
split_huge_page().

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel<riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-13 15:35:57 -07:00
..
backing-dev.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-10-26 17:58:44 -07:00
bootmem.c
bounce.c
compaction.c mm: compaction: prevent division-by-zero during user-requested compaction 2011-01-20 17:02:05 -08:00
debug-pagealloc.c
dmapool.c mm/dmapool.c: use TASK_UNINTERRUPTIBLE in dma_pool_alloc() 2011-01-13 17:32:48 -08:00
fadvise.c
failslab.c
filemap_xip.c
filemap.c mm: remove likely() from grab_cache_page_write_begin() 2011-01-13 17:32:36 -08:00
fremap.c
highmem.c mm,x86: fix kmap_atomic_push vs ioremap_32.c 2010-10-27 18:03:05 -07:00
huge_memory.c mm: use correct numa policy node for transparent hugepages 2011-03-04 17:53:39 -08:00
hugetlb.c hugetlb: fix handling of parse errors in sysfs 2011-01-13 17:32:49 -08:00
hwpoison-inject.c
init-mm.c
internal.h Revert "mm: batch activate_page() to reduce lock contention" 2011-01-17 14:42:19 -08:00
Kconfig mm: compaction: don't depend on HUGETLB_PAGE 2011-01-26 10:50:02 +10:00
Kconfig.debug
kmemcheck.c
kmemleak-test.c kmemleak: remove memset by using kzalloc 2011-01-27 18:31:51 +00:00
kmemleak.c kmemleak: Allow kmemleak metadata allocations to fail 2011-01-27 18:32:06 +00:00
ksm.c ksm: drain pagevecs to lru 2011-01-13 17:32:49 -08:00
maccess.c MN10300: Save frame pointer in thread_info struct rather than global var 2010-10-27 17:29:01 +01:00
madvise.c thp: khugepaged: make khugepaged aware about madvise 2011-01-13 17:32:47 -08:00
Makefile thp: transparent hugepage core 2011-01-13 17:32:42 -08:00
memblock.c memblock: don't adjust size in memblock_find_base() 2011-02-11 16:12:20 -08:00
memcontrol.c memcg: fix event counting breakage from recent THP update 2011-02-02 16:03:19 -08:00
memory_hotplug.c Merge branch 'slub/hotplug' into slab/urgent 2011-01-15 13:28:17 +02:00
memory-failure.c thp: fix unsuitable behavior for hwpoisoned tail page 2011-02-02 16:03:19 -08:00
memory.c mm: prevent concurrent unmap_mapping_range() on the same inode 2011-02-23 19:52:52 -08:00
mempolicy.c mm: use correct numa policy node for transparent hugepages 2011-03-04 17:53:39 -08:00
mempool.c
migrate.c mm: grab rcu read lock in move_pages() 2011-02-25 15:07:36 -08:00
mincore.c thp: mincore transparent hugepage support 2011-01-13 17:32:44 -08:00
mlock.c mlock: operate on any regions with protection != PROT_NONE 2011-02-02 10:20:50 +11:00
mm_init.c
mmap.c brk: fix min_brk lower bound computation for COMPAT_BRK 2011-01-13 17:32:48 -08:00
mmu_context.c
mmu_notifier.c thp: mmu_notifier_test_young 2011-01-13 17:32:46 -08:00
mmzone.c mm: page allocator: adjust the per-cpu counter threshold when memory is low 2011-01-13 17:32:31 -08:00
mprotect.c thp: mprotect: transparent huge page support 2011-01-13 17:32:44 -08:00
mremap.c mm: fix possible cause of a page_mapped BUG 2011-02-23 21:55:06 -08:00
msync.c
nommu.c mlock: do not hold mmap_sem for extended periods of time 2011-01-13 17:32:36 -08:00
oom_kill.c oom: kill all threads sharing oom killed task's mm 2010-10-26 16:52:05 -07:00
page_alloc.c mm: fix dubious code in __count_immobile_pages() 2011-02-25 15:07:37 -08:00
page_cgroup.c
page_io.c
page_isolation.c mm: page_isolation: codeclean fix comment and rm unneeded val init 2010-10-26 16:52:11 -07:00
page-writeback.c writeback: avoid unnecessary determine_dirtyable_memory call 2011-01-13 17:32:38 -08:00
pagewalk.c thp: split_huge_page_mm/vma 2011-01-13 17:32:41 -08:00
percpu-km.c
percpu-vm.c mm: remove gfp mask from pcpu_get_vm_areas 2011-01-13 17:32:34 -08:00
percpu.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-01-13 10:05:56 -08:00
pgtable-generic.c mm/pgtable-generic.c: fix CONFIG_SWAP=n build 2011-01-26 10:49:58 +10:00
prio_tree.c
quicklist.c
readahead.c
rmap.c thp: fix page_referenced to modify mapcount/vm_flags only if page is found 2011-03-13 15:35:57 -07:00
shmem.c fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
slab.c mm/slab.c: make local symbols static 2011-01-15 13:28:36 +02:00
slob.c kernel: kmem_ptr_validate considered harmful 2011-01-07 17:50:16 +11:00
slub.c Merge branch 'slub/hotplug' into slab/urgent 2011-01-15 13:28:17 +02:00
sparse-vmemmap.c tree-wide: fix comment/printk typos 2010-11-01 15:38:34 -04:00
sparse.c thp: remove PG_buddy 2011-01-13 17:32:43 -08:00
swap_state.c thp: split_huge_page paging 2011-01-13 17:32:41 -08:00
swap.c Revert "mm: simplify code of swap.c" 2011-01-17 14:42:34 -08:00
swapfile.c mm: fix refcounting in swapon 2011-02-24 08:55:01 -08:00
thrash.c
truncate.c memcg: more mem_cgroup_uncharge() batching 2011-02-25 15:07:37 -08:00
util.c kernel: kmem_ptr_validate considered harmful 2011-01-07 17:50:16 +11:00
vmalloc.c Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2011-01-13 20:15:35 -08:00
vmscan.c mm: vmscan: stop reclaim/compaction earlier due to insufficient progress if !__GFP_REPEAT 2011-02-25 15:07:36 -08:00
vmstat.c thp: transparent hugepage vmstat 2011-01-13 17:32:43 -08:00