From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
The jump labels try_prev and none are not really needed
in find_mergeable_anon_vma(), eliminate them to improve
readability.
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
-v2:
Fix commit descriptions and further simplify the code
as suggested by David Hildenbrand and John Hubbard.
-v3:
Rewrite patch version info. Don't show this in commit log.
-v4:
Get rid of var near completely as well.
---
mm/mmap.c | 36 ++++++++++++++++--------------------
1 file changed, 16 insertions(+), 20 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 91d5e097a4ed..4d93bda30eac 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1273,26 +1273,22 @@ static struct anon_vma *reusable_anon_vma(struct vm_area_struct *old, struct vm_
*/
struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *vma)
{
- struct anon_vma *anon_vma;
- struct vm_area_struct *near;
-
- near = vma->vm_next;
- if (!near)
- goto try_prev;
-
- anon_vma = reusable_anon_vma(near, vma, near);
- if (anon_vma)
- return anon_vma;
-try_prev:
- near = vma->vm_prev;
- if (!near)
- goto none;
-
- anon_vma = reusable_anon_vma(near, near, vma);
- if (anon_vma)
- return anon_vma;
-none:
+ struct anon_vma *anon_vma = NULL;
+
+ /* Try next first. */
+ if (vma->vm_next) {
+ anon_vma = reusable_anon_vma(vma->vm_next, vma, vma->vm_next);
+ if (anon_vma)
+ return anon_vma;
+ }
+
+ /* Try prev next. */
+ if (vma->vm_prev)
+ anon_vma = reusable_anon_vma(vma->vm_prev, vma->vm_prev, vma);
+
/*
+ * We might reach here with anon_vma == NULL if we can't find
+ * any reusable anon_vma.
* There's no absolute need to look only at touching neighbours:
* we could search further afield for "compatible" anon_vmas.
* But it would probably just be a waste of time searching,
@@ -1300,7 +1296,7 @@ struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *vma)
* We're trying to allow mprotect remerging later on,
* not trying to minimize memory used for anon_vmas.
*/
- return NULL;
+ return anon_vma;
}
/*
--
2.21.GIT
