path: root/mm
diff options
authorMichal Hocko <mhocko@suse.cz>2012-10-08 16:33:31 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-13 05:38:50 +0900
commit26fc07d8da4aa118cfe44776c2d2ddef8ef5f641 (patch)
tree733486cf1bf258f6373ec7f005d27e36d726bb60 /mm
parent70fb727d0900836b71ebf7a7badaa7b7c9068102 (diff)
hugetlb: do not use vma_hugecache_offset() for vma_prio_tree_foreach
commit 36e4f20af833d1ce196e6a4ade05dc26c44652d1 upstream. Commit 0c176d52b0b2 ("mm: hugetlb: fix pgoff computation when unmapping page from vma") fixed pgoff calculation but it has replaced it by vma_hugecache_offset() which is not approapriate for offsets used for vma_prio_tree_foreach() because that one expects index in page units rather than in huge_page_shift. Johannes said: : The resulting index may not be too big, but it can be too small: assume : hpage size of 2M and the address to unmap to be 0x200000. This is regular : page index 512 and hpage index 1. If you have a VMA that maps the file : only starting at the second huge page, that VMAs vm_pgoff will be 512 but : you ask for offset 1 and miss it even though it does map the page of : interest. hugetlb_cow() will try to unmap, miss the vma, and retry the : cow until the allocation succeeds or the skipped vma(s) go away. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index a799df59d310..c384e0901f9c 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2431,7 +2431,8 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
* from page cache lookup which is in HPAGE_SIZE units.
address = address & huge_page_mask(h);
- pgoff = vma_hugecache_offset(h, vma, address);
+ pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) +
+ vma->vm_pgoff;
mapping = vma->vm_file->f_dentry->d_inode->i_mapping;