Messages in this thread | | | Date | Wed, 9 Jun 2010 11:55:18 +0100 | From | Mel Gorman <> | Subject | Re: [PATCH 07/28] extend KSM refcounts to the anon_vma root |
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On Mon, Jun 07, 2010 at 01:07:01PM +0200, Peter Zijlstra wrote: > From: Rik van Riel <riel@redhat.com> > > 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> > Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> > LKML-Reference: <20100526154124.04607d04@annuminas.surriel.com>
Acked-by: Mel Gorman <mel@csn.ul.ie
> <SNIP>
-- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab
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