linux-kernel - Re: [Intel-gfx] Interrupt latency on some 945GM platforms

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sat, 25 Sep 2010 12:28:20 +0200
From:	Paolo Ornati <ornati@...il.com>
To:	Jesse Barnes <jbarnes@...tuousgeek.org>
Cc:	Vasily Khoruzhick <anarsoul@...il.com>,
	Simon Farnsworth <simon.farnsworth@...lan.co.uk>,
	intel-gfx@...ts.freedesktop.org,
	Sitsofe Wheeler <sitsofe@...oo.com>,
	Venkatesh Pallipadi <venki@...gle.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	linux-kernel@...r.kernel.org
Subject: Re: [Intel-gfx] Interrupt latency on some 945GM platforms

On Tue, 21 Sep 2010 15:56:53 -0700
Jesse Barnes <jbarnes@...tuousgeek.org> wrote:

> > I've a laptop with 945GM (Asus x5dij) and with 2.6.32+ kernels I'm
> > having random, but not frequent, screen flickering problems (for some
> > reasons 2.6.31 works fine).
> > 
> > Problem goes away with "nohz=off".
> > 
> > I'll try with "processor.max_cstate=?" and see if that works too.  
> 
> Can you guys try something like this?  My theory is that 945GM has some
> power management behavior we're failing to configure correctly.  If
> disabling it works, then it's likely related.

UPDATE: "processor.max_cstate=2" doesn't solve the sporadic flicker
problem.

The patch, applied on top of 2.6.35.4, freezes the laptop on boot.

Summary:
	nohz=off		good
	processor.max_cstate=1	good
	processor.max_cstate=2	bad

Bye,

-- 
	Paolo Ornati
	Linux 2.6.35.4 on x86_64
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/