path: root/mm
diff options
authorHugh Dickins <hugh.dickins@tiscali.co.uk>2009-09-21 17:03:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-22 07:17:40 -0700
commit1ac0cb5d0e22d5e483f56b2bc12172dec1cf7536 (patch)
tree68114711dc747a557895896af991623438034c2d /mm
parent2a15efc953b26ad57d7d38b9e6782d57e53b4ab2 (diff)
mm: fix anonymous dirtying
do_anonymous_page() has been wrong to dirty the pte regardless. If it's not going to mark the pte writable, then it won't help to mark it dirty here, and clogs up memory with pages which will need swap instead of being thrown away. Especially wrong if no overcommit is chosen, and this vma is not yet VM_ACCOUNTed - we could exceed the limit and OOM despite no overcommit. Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: <stable@kernel.org> Acked-by: Rik van Riel <riel@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 6359a4f80c4..fc38d4ed9ad 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2653,7 +2653,8 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
goto oom_free_page;
entry = mk_pte(page, vma->vm_page_prot);
- entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ if (vma->vm_flags & VM_WRITE)
+ entry = pte_mkwrite(pte_mkdirty(entry));
page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
if (!pte_none(*page_table))