From: Jesse Barnes <jbarnes@virtuousgeek.org>
Subject: Re: Interrupt latency on some 945GM platforms
Date: Fri, 24 Sep 2010 11:41:22 -0700
Message-ID: <20100924114122.4bfce00e@jbarnes-desktop>
References: <201009132336.17310.anarsoul@gmail.com>
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	<20100914224111.GA14467@sucs.org>
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To: Vasily Khoruzhick <anarsoul@gmail.com>
Cc: Sitsofe Wheeler <sitsofe@yahoo.com>, Thomas Gleixner <tglx@linutronix.de>, Venkatesh Pallipadi <venki@google.com>, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org
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On Thu, 16 Sep 2010 18:03:04 +0300
Vasily Khoruzhick <anarsoul@gmail.com> wrote:

> =D0=92 =D1=81=D0=BE=D0=BE=D0=B1=D1=89=D0=B5=D0=BD=D0=B8=D0=B8 =D0=BE=D1=
=82 15 of September 2010 01:41:11 =D0=B0=D0=B2=D1=82=D0=BE=D1=80 Sitsof=
e Wheeler =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB:
> > > >     processor.max_cstate=3D2
> > >=20
> > > Nope, it doesn't work with max_cstate=3D2
> >=20
> > Perhaps intel_idle is being used? Any mention of it in dmesg?
>=20
> Sitsofe, maybe you misunderstood me, I mean with max_cstate=3D1 graph=
ics is=20
> smooth, with higher values (i.e. max_cstate=3D2) graphics is jerky.
>=20
> Btw, Jesse, any comments/solutions/workarounds except one with=20
> processor.max_cstate=3D1 in kernel commandline? Should I file a bug o=
n fdo=20
> bugzilla?

=46DO bug for this is https://bugs.freedesktop.org/show_bug.cgi?id=3D30=
364.

I still don't have a root cause, but at least we have a workaround.

--=20
Jesse Barnes, Intel Open Source Technology Center