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author | Rik van Riel <riel@redhat.com> | 2010-08-09 17:18:41 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-09 20:44:55 -0700 |
commit | 76545066c8521f3e32c849744744842b4df25b79 (patch) | |
tree | 978b6b003f63e1e22618586b7d9c2dd8ef363614 /fs/ext2/Makefile | |
parent | mm: always lock the root (oldest) anon_vma (diff) | |
download | linux-dev-76545066c8521f3e32c849744744842b4df25b79.tar.xz linux-dev-76545066c8521f3e32c849744744842b4df25b79.zip |
mm: extend KSM refcounts to the anon_vma root
KSM reference counts can cause an anon_vma to exist after the processe it
belongs to have already exited. Because the anon_vma lock now lives in
the root anon_vma, we need to ensure that the root anon_vma stays around
until after all the "child" anon_vmas have been freed.
The obvious way to do this is to have a "child" anon_vma take a reference
to the root in anon_vma_fork. When the anon_vma is freed at munmap or
process exit, we drop the refcount in anon_vma_unlink and possibly free
the root anon_vma.
The KSM anon_vma reference count function also needs to be modified to
deal with the possibility of freeing 2 levels of anon_vma. The easiest
way to do this is to break out the KSM magic and make it generic.
When compiling without CONFIG_KSM, this code is compiled out.
Signed-off-by: Rik van Riel <riel@redhat.com>
Tested-by: Larry Woodman <lwoodman@redhat.com>
Acked-by: Larry Woodman <lwoodman@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ext2/Makefile')
0 files changed, 0 insertions, 0 deletions