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| author | Hugh Dickins <hugh.dickins@tiscali.co.uk> | 2009-12-15 04:59:22 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-15 19:53:19 +0300 |
| commit | 73848b4684e84a84cfd1555af78d41158f31e16b (patch) | |
| tree | b71ba30e2b20cbc45740a38e9b5aa51b8c2ea60e | |
| parent | 08beca44dfb0ab008e365163df70dbd302ae1508 (diff) | |
| download | linux-73848b4684e84a84cfd1555af78d41158f31e16b.tar.xz | |
ksm: fix mlockfreed to munlocked
When KSM merges an mlocked page, it has been forgetting to munlock it:
that's been left to free_page_mlock(), which reports it in /proc/vmstat as
unevictable_pgs_mlockfreed instead of unevictable_pgs_munlocked (and
whinges "Page flag mlocked set for process" in mmotm, whereas mainline is
silently forgiving). Call munlock_vma_page() to fix that.
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Chris Wright <chrisw@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/internal.h | 3 | ||||
| -rw-r--r-- | mm/ksm.c | 4 | ||||
| -rw-r--r-- | mm/mlock.c | 4 |
3 files changed, 8 insertions, 3 deletions
diff --git a/mm/internal.h b/mm/internal.h index cb7d92d0a46d..a4b927cdca09 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -105,9 +105,10 @@ static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page) } /* - * must be called with vma's mmap_sem held for read, and page locked. + * must be called with vma's mmap_sem held for read or write, and page locked. */ extern void mlock_vma_page(struct page *page); +extern void munlock_vma_page(struct page *page); /* * Clear the page's PageMlocked(). This can be useful in a situation where @@ -34,6 +34,7 @@ #include <linux/ksm.h> #include <asm/tlbflush.h> +#include "internal.h" /* * A few notes about the KSM scanning process, @@ -762,6 +763,9 @@ static int try_to_merge_one_page(struct vm_area_struct *vma, pages_identical(page, kpage)) err = replace_page(vma, page, kpage, orig_pte); + if ((vma->vm_flags & VM_LOCKED) && !err) + munlock_vma_page(page); + unlock_page(page); out: return err; diff --git a/mm/mlock.c b/mm/mlock.c index 48691fb08514..adcbe9032b58 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -99,14 +99,14 @@ void mlock_vma_page(struct page *page) * not get another chance to clear PageMlocked. If we successfully * isolate the page and try_to_munlock() detects other VM_LOCKED vmas * mapping the page, it will restore the PageMlocked state, unless the page - * is mapped in a non-linear vma. So, we go ahead and SetPageMlocked(), + * is mapped in a non-linear vma. So, we go ahead and ClearPageMlocked(), * perhaps redundantly. * If we lose the isolation race, and the page is mapped by other VM_LOCKED * vmas, we'll detect this in vmscan--via try_to_munlock() or try_to_unmap() * either of which will restore the PageMlocked state by calling * mlock_vma_page() above, if it can grab the vma's mmap sem. */ -static void munlock_vma_page(struct page *page) +void munlock_vma_page(struct page *page) { BUG_ON(!PageLocked(page)); |