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Date: Wed, 16 Apr 2008 12:15:08 -0700 (PDT)
From: Christoph Lameter <clameter@sgi.com>
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To: Robin Holt <holt@sgi.com>
cc: Andrea Arcangeli <andrea@qumranet.com>, akpm@linux-foundation.org,
       Nick Piggin <npiggin@suse.de>, Steve Wise <swise@opengridcomputing.com>,
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Subject: Re: [PATCH 1 of 9] Lock the entire mm to prevent any mmu related
 operation to happen
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On Wed, 16 Apr 2008, Robin Holt wrote:

> On Wed, Apr 16, 2008 at 11:35:38AM -0700, Christoph Lameter wrote:
> > On Wed, 16 Apr 2008, Robin Holt wrote:
> > 
> > > I don't think this lock mechanism is completely working.  I have
> > > gotten a few failures trying to dereference 0x100100 which appears to
> > > be LIST_POISON1.
> > 
> > How does xpmem unregistering of notifiers work?
> 
> For the tests I have been running, we are waiting for the release
> callout as part of exit.

Some more details on the failure may be useful. AFAICT list_del[_rcu] is 
the culprit here and that is only used on release or unregister.