Messages in this thread | | | Date | Thu, 27 May 2010 23:31:34 +0900 | From | Minchan Kim <> | Subject | Re: [PATCH 5/5] extend KSM refcounts to the anon_vma root |
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On Wed, May 26, 2010 at 03:41:24PM -0400, Rik van Riel wrote: > Subject: 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> Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Now I understand this patch. Thanks, Rik. -- Kind regards, Minchan Kim
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