path: root/mm
diff options
authorHugh Dickins <hugh@veritas.com>2008-02-04 22:29:23 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-05 09:44:18 -0800
commit5a9bbdcd29adbb786c53eba1dfc3c2d256020d6b (patch)
tree44fbcff2ad653d7a328bab3144d63da9aaea6f7a /mm
parent9eccf2a816ed0aad82b577de6a40cd098ad41944 (diff)
mm: don't waste swap on locked pages
try_to_unmap always fails on a page found in a VM_LOCKED vma (unless migrating), and recycles it back to the active list. But if it's an anonymous page, we've already allocated swap to it: just wasting swap. Spot locked pages in page_referenced_one and treat them as referenced. Signed-off-by: Hugh Dickins <hugh@veritas.com> Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ethan Solomita <solo@google.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, 4 insertions, 1 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 0334c8f6b741..57ad276900c9 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -283,7 +283,10 @@ static int page_referenced_one(struct page *page,
if (!pte)
goto out;
- if (ptep_clear_flush_young(vma, address, pte))
+ if (vma->vm_flags & VM_LOCKED) {
+ referenced++;
+ *mapcount = 1; /* break early from loop */
+ } else if (ptep_clear_flush_young(vma, address, pte))
/* Pretend the page is referenced if the task has the

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