From: Chris Wilson <chris@chris-wilson.co.uk>
To: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH] drm/i915: Only free the unpin_work if cancelled before being run
Date: Tue, 17 Apr 2012 10:53:24 +0100 [thread overview]
Message-ID: <1334656418_11970@CP5-2952> (raw)
In-Reply-To: <1334654978-16021-1-git-send-email-chris@chris-wilson.co.uk>
On Tue, 17 Apr 2012 10:29:38 +0100, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> The unpin worker frees it work struct and so during intel_crtc_disable
> we should only also free the work struct if cancel_work_sync() reports
> that it successfully cancelled the work prior to it being executed and
> thus avoid the double free.
>
> The impact is only for people unloading modules during a fullscreen game
> or movie playback, so extremely small.
Futher review (hunting for some sign of workqueue corruption, cf
https://bugs.freedesktop.org/show_bug.cgi?id=48798) says that if work is
non-NULL here it will not have been scheduled so cancel_work_sync() will
always return true.
Which also means that we have no way of waiting upon the scheduled
unpin_work. :|
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
next prev parent reply other threads:[~2012-04-17 9:53 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-17 9:29 [PATCH] drm/i915: Only free the unpin_work if cancelled before being run Chris Wilson
2012-04-17 9:47 ` Daniel Vetter
2012-04-17 9:53 ` Chris Wilson [this message]
2012-04-17 10:33 ` Daniel Vetter
2012-04-17 13:30 ` Chris Wilson
2012-04-17 13:44 ` Daniel Vetter
2012-04-17 13:45 ` Daniel Vetter
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