| Date | Fri, 9 Apr 2010 09:04:16 +0200 | From | Christian Ehrhardt <> | Subject | Re: [PATCH 05/13] mm: Make use of the anon_vma ref count |
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Hi,
On Thu, Apr 08, 2010 at 09:17:42PM +0200, Peter Zijlstra wrote: > @@ -302,23 +307,33 @@ again: > goto out; > > anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON); > - spin_lock(&anon_vma->lock); > + if (!atomic_inc_not_zero(&anon_vma->ref)) > + anon_vma = NULL; > > if (page_rmapping(page) != anon_vma) { > - spin_unlock(&anon_vma->lock); > + anon_vma_put(anon_vma); > goto again; > }
AFAICS anon_vma_put might be called with anon_vma == NULL here which will oops on the ref count. Not sure if
page_rmapping(page) == anon_vma == NULL
is possible, too.
regards Christian
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