From: Daniel Vetter <daniel@ffwll.ch>
To: Jan Niggemann <jn@hz6.de>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: i915 irq storm mitigation in 3.10
Date: Mon, 8 Jul 2013 22:03:16 +0200 [thread overview]
Message-ID: <20130708200316.GG18285@phenom.ffwll.local> (raw)
In-Reply-To: <2b828191fde71b2243f883e2dbb28d6d@hz6.de>
On Sat, Jul 06, 2013 at 11:41:07PM +0200, Jan Niggemann wrote:
> Hi list,
>
> I'm not sure, but I think the recent patch to keep i915 systems from
> locking up / slowing down in case of irq storms didn't fully help.
> I compiled 3.10, but every now and then, my system has the same
> symptoms as before.
>
> grep storm /var/log/messages
> Jul 5 21:55:43 muretop kernel: [ 324.767375] [drm] HPD interrupt
> storm detected on connector DP-3: switching from hotplug detection
> to polling
> Jul 6 23:05:57 muretop kernel: [ 200.372208] [drm] HPD interrupt
> storm detected on connector HDMI-A-1: switching from hotplug
> detection to polling
> Jul 6 23:07:51 muretop kernel: [ 313.752039] [drm] HPD interrupt
> storm detected on connector DP-3: switching from hotplug detection
> to pol
>
> I notice up to 50% CPU from kworker/u8:0 when my system slows down.
>
> I'm new to kernel development, but if you tell me what to do, I'm
> very willing to help diagnosing this.
Seems to work as advertised, once we detect a storm we kill the hotplug
interrupt. Note that since on many systems these storms only happen in
certain conditions (e.g. specific battery charger state) we'll re-enable
the interrupts every 2 minutes to check whether the storm has passed
(there's not really any other way).
But every time this happens we only let through a few interrupts, so this
shouldn't affect you badly. Can you please check whether those slowdowns
line up with 2 minute intervalls?
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
next prev parent reply other threads:[~2013-07-08 20:03 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-06 21:41 i915 irq storm mitigation in 3.10 Jan Niggemann
2013-07-08 20:03 ` Daniel Vetter [this message]
2013-07-21 20:23 ` Jan Niggemann
2013-07-21 20:43 ` Daniel Vetter
2013-07-22 6:14 ` Jan Niggemann
2013-07-22 6:26 ` Daniel Vetter
2013-07-22 8:04 ` Egbert Eich
2013-07-22 19:28 ` Jan Niggemann
2013-07-22 20:36 ` Egbert Eich
2013-07-23 8:17 ` Daniel Vetter
2013-07-23 11:26 ` Egbert Eich
2013-07-24 20:52 ` Jan Niggemann
2013-07-25 7:50 ` Egbert Eich
2013-07-25 9:58 ` Daniel Vetter
2013-07-25 11:18 ` Egbert Eich
2013-07-25 21:23 ` Jan Niggemann
2013-07-26 5:11 ` Egbert Eich
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