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Date: Wed, 7 May 2008 10:59:48 -0500
From: Robin Holt <holt@sgi.com>
To: Andrea Arcangeli <andrea@qumranet.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
       Christoph Lameter <clameter@sgi.com>, Jack Steiner <steiner@sgi.com>,
       Robin Holt <holt@sgi.com>, Nick Piggin <npiggin@suse.de>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>,
       kvm-devel@lists.sourceforge.net, Kanoj Sarcar <kanojsarcar@yahoo.com>,
       Roland Dreier <rdreier@cisco.com>,
       Steve Wise <swise@opengridcomputing.com>, linux-kernel@vger.kernel.org,
       Avi Kivity <avi@qumranet.com>, linux-mm@kvack.org,
       general@lists.openfabrics.org, Hugh Dickins <hugh@veritas.com>,
       Rusty Russell <rusty@rustcorp.com.au>,
       Anthony Liguori <aliguori@us.ibm.com>, Chris Wright <chrisw@redhat.com>,
       Marcelo Tosatti <marcelo@kvack.org>, Eric Dumazet <dada1@cosmosbay.com>,
       "Paul E. McKenney" <paulmck@us.ibm.com>
Subject: Re: [PATCH 02 of 11] get_task_mm
Message-ID: <20080507155948.GO18857@sgi.com>
References: <patchbomb.1210170950@duo.random> <c5badbefeee07518d9d1.1210170952@duo.random>
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You can drop this patch.

This turned out to be a race in xpmem.  It "appeared" as if it were a
race in get_task_mm, but it really is not.  The current->mm field is
cleared under the task_lock and the task_lock is grabbed by get_task_mm.

I have been testing you v15 version without this patch and not
encountere the problem again (now that I fixed my xpmem race).

Thanks,
Robin

On Wed, May 07, 2008 at 04:35:52PM +0200, Andrea Arcangeli wrote:
> # HG changeset patch
> # User Andrea Arcangeli <andrea@qumranet.com>
> # Date 1210115127 -7200
> # Node ID c5badbefeee07518d9d1acca13e94c981420317c
> # Parent  e20917dcc8284b6a07cfcced13dda4cbca850a9c
> get_task_mm