path: root/mm/mempolicy.c
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2012-03-06 18:23:36 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-06 18:23:36 -0800
commit097d59106a8e4b42d07c9892fdd7790f1659c6ff (patch)
treebabf61a0287b0f09f80580847274877831ed6869 /mm/mempolicy.c
parent71fece9511717750d86691e0f517ad04f3c8a801 (diff)
vm: avoid using find_vma_prev() unnecessarily
Several users of "find_vma_prev()" were not in fact interested in the previous vma if there was no primary vma to be found either. And in those cases, we're much better off just using the regular "find_vma()", and then "prev" can be looked up by just checking vma->vm_prev. The find_vma_prev() semantics are fairly subtle (see Mikulas' recent commit 83cd904d271b: "mm: fix find_vma_prev"), and the whole "return prev by reference" means that it generates worse code too. Thus this "let's avoid using this inconvenient and clearly too subtle interface when we don't really have to" patch. Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mempolicy.c')
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 06b145fb64a..47296fee23d 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -640,10 +640,11 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
unsigned long vmstart;
unsigned long vmend;
- vma = find_vma_prev(mm, start, &prev);
+ vma = find_vma(mm, start);
if (!vma || vma->vm_start > start)
return -EFAULT;
+ prev = vma->vm_prev;
if (start > vma->vm_start)
prev = vma;