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| author | David Howells <dhowells@redhat.com> | 2010-01-16 02:01:34 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-01-16 21:15:40 +0100 |
| commit | 779c10232ceb11c1b259232c4845cfb2850287b7 (patch) | |
| tree | 972b07acdcff03b20c84d42425a64b231df52aaa /mm/util.c | |
| parent | nommu: struct vm_region's vm_usage count need not be atomic (diff) | |
| download | linux-779c10232ceb11c1b259232c4845cfb2850287b7.tar.xz linux-779c10232ceb11c1b259232c4845cfb2850287b7.zip | |
nommu: remove a superfluous check of vm_region::vm_usage
In split_vma(), there's no need to check if the VMA being split has a
region that's in use by more than one VMA because:
(1) The preceding test prohibits splitting of non-anonymous VMAs and regions
(eg: file or chardev backed VMAs).
(2) Anonymous regions can't be mapped multiple times because there's no handle
by which to refer to the already existing region.
(3) If a VMA has previously been split, then the region backing it has also
been split into two regions, each of usage 1.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/util.c')
0 files changed, 0 insertions, 0 deletions