Michel Lespinasse e15f8c01af mlock: fix race when munlocking pages in do_wp_page() ... vmscan can lazily find pages that are mapped within VM_LOCKED vmas, and set the PageMlocked bit on these pages, transfering them onto the unevictable list. When do_wp_page() breaks COW within a VM_LOCKED vma, it may need to clear PageMlocked on the old page and set it on the new page instead. This change fixes an issue where do_wp_page() was clearing PageMlocked on the old page while the pte was still pointing to it (as well as rmap). Therefore, we were not protected against vmscan immediately transfering the old page back onto the unevictable list. This could cause pages to get stranded there forever. I propose to move the corresponding code to the end of do_wp_page(), after the pte (and rmap) have been pointed to the new page. Additionally, we can use munlock_vma_page() instead of clear_page_mlock(), so that the old page stays mlocked if there are still other VM_LOCKED vmas mapping it. Signed-off-by: Michel Lespinasse <walken@google.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2011-02-11 16:12:20 -08:00
..
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	x86, memblock: Replace e820_/_early string with memblock_	2010-08-27 11:13:47 -07:00
bounce.c	bounce: call flush_dcache_page() after bounce_copy_vec()	2010-09-09 18:57:25 -07:00
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	readahead: introduce FMODE_RANDOM for POSIX_FADV_RANDOM	2010-03-06 11:26:25 -08:00
failslab.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
filemap.c	mm: remove likely() from grab_cache_page_write_begin()	2011-01-13 17:32:36 -08:00
filemap_xip.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
fremap.c	Avoid pgoff overflow in remap_file_pages	2010-09-25 09:34:58 -07:00
highmem.c	mm,x86: fix kmap_atomic_push vs ioremap_32.c	2010-10-27 18:03:05 -07:00
huge_memory.c	thp: fix the wrong reported address of hwpoisoned hugepages	2011-02-02 16:03:19 -08:00
hugetlb.c	hugetlb: fix handling of parse errors in sysfs	2011-01-13 17:32:49 -08:00
hwpoison-inject.c	HWPOISON, hugetlb: support hwpoison injection for hugepage	2010-08-11 09:23:11 +02:00
init-mm.c	mm: provide init_mm mm_context initializer	2010-08-09 20:44:54 -07:00
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	trivial: improve help text for mm debug config options	2009-09-21 15:14:57 +02:00
kmemcheck.c	kmemcheck: Fix build errors due to missing slab.h	2010-03-30 22:02:32 +09:00
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-failure.c	thp: fix unsuitable behavior for hwpoisoned tail page	2011-02-02 16:03:19 -08:00
memory.c	mlock: fix race when munlocking pages in do_wp_page()	2011-02-11 16:12:20 -08:00
memory_hotplug.c	Merge branch 'slub/hotplug' into slab/urgent	2011-01-15 13:28:17 +02:00
mempolicy.c	thp: add numa awareness to hugepage allocations	2011-01-13 17:32:45 -08:00
mempool.c	mm: remove broken 'kzalloc' mempool	2009-09-22 07:17:35 -07:00
migrate.c	mm/migration: fix page corruption during hugepage migration	2011-02-02 16:03:18 -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	exit: fix oops in sync_mm_rss	2010-03-24 16:31:21 -07:00
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	thp: split_huge_page_mm/vma	2011-01-13 17:32:41 -08:00
msync.c	sanitize vfs_fsync calling conventions	2010-05-21 18:31:21 -04:00
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-writeback.c	writeback: avoid unnecessary determine_dirtyable_memory call	2011-01-13 17:32:38 -08:00
page_alloc.c	mm: clear pages_scanned only if draining a pcp adds pages to the buddy allocator	2011-01-26 10:50:01 +10:00
page_cgroup.c	kmemleak: Annotate false positive in init_section_page_cgroup()	2010-07-19 11:54:14 +01:00
page_io.c	block: unify flags for struct bio and struct request	2010-08-07 18:20:39 +02:00
page_isolation.c	mm: page_isolation: codeclean fix comment and rm unneeded val init	2010-10-26 16:52:11 -07:00
pagewalk.c	thp: split_huge_page_mm/vma	2011-01-13 17:32:41 -08:00
percpu-km.c	percpu: clear memory allocated with the km allocator	2010-10-02 10:28:42 +03:00
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	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
readahead.c	readahead.c: fix comment	2010-05-25 08:07:00 -07:00
rmap.c	memcg: create extensible page stat update routines	2011-01-13 17:32:50 -08:00
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.c	Revert "mm: simplify code of swap.c"	2011-01-17 14:42:34 -08:00
swap_state.c	thp: split_huge_page paging	2011-01-13 17:32:41 -08:00
swapfile.c	thp: split_huge_page paging	2011-01-13 17:32:41 -08:00
thrash.c
truncate.c	mm: fix truncate_setsize() comment	2011-01-20 17:02:06 -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: fix deferred congestion timeout if preferred zone is not allowed	2011-01-26 10:50:00 +10:00
vmstat.c	thp: transparent hugepage vmstat	2011-01-13 17:32:43 -08:00