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Date: Fri, 7 Apr 2017 11:02:11 +0100
From: Chris Wilson <chris@chris-wilson.co.uk>
To: Andrea Arcangeli <aarcange@redhat.com>
Cc: Martin Kepplinger <martink@posteo.de>,
        Thorsten Leemhuis <regressions@leemhuis.info>, daniel.vetter@intel.com,
        Dave Airlie <airlied@gmail.com>, intel-gfx@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 2/5] i915: flush gem obj freeing workqueues to add
 accuracy to the i915 shrinker
Message-ID: <20170407100211.GG10496@nuc-i3427.alporthouse.com>
Mail-Followup-To: Chris Wilson <chris@chris-wilson.co.uk>,
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On Fri, Apr 07, 2017 at 01:23:44AM +0200, Andrea Arcangeli wrote:
> Waiting a RCU grace period only guarantees the work gets queued, but
> until after the queued workqueue returns, there's no guarantee the
> memory was actually freed. So flush the work to provide better
> guarantees to the reclaim code in addition of waiting a RCU grace
> period to pass.

We are not allowed to call flush_work() from the shrinker, the workqueue
doesn't have and can't have the right reclaim flags.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre