From 03ef83af528899aa339e42d8024b37e2f434fba4 Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Wed, 26 Aug 2009 14:29:23 -0700 Subject: mm: fix for infinite churning of mlocked pages An mlocked page might lose the isolatation race. This causes the page to clear PG_mlocked while it remains in a VM_LOCKED vma. This means it can be put onto the [in]active list. We can rescue it by using try_to_unmap() in shrink_page_list(). But now, As Wu Fengguang pointed out, vmscan has a bug. If the page has PG_referenced, it can't reach try_to_unmap() in shrink_page_list() but is put into the active list. If the page is referenced repeatedly, it can remain on the [in]active list without being moving to the unevictable list. This patch fixes it. Reported-by: Wu Fengguang Signed-off-by: Minchan Kim Reviewed-by: KOSAKI Motohiro < Cc: Lee Schermerhorn Acked-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/rmap.c | 1 + 1 file changed, 1 insertion(+) (limited to 'mm/rmap.c') diff --git a/mm/rmap.c b/mm/rmap.c index 836c6c6..0895b5c 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -358,6 +358,7 @@ static int page_referenced_one(struct page *page, */ if (vma->vm_flags & VM_LOCKED) { *mapcount = 1; /* break early from loop */ + *vm_flags |= VM_LOCKED; goto out_unmap; } -- cgit v1.1