From: "Björn Steinbrink" <B.Steinbrink@gmx.de>
To: "Pascal Brückner" <pascal_2001@web.de>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Strange C3/C4 sleep state behaviour
Date: Fri, 16 May 2008 00:18:03 +0200 [thread overview]
Message-ID: <20080515221803.GA17259@atjola.homenet> (raw)
In-Reply-To: <482CA6E4.1010807@web.de>
On 2008.05.15 23:11:00 +0200, Pascal Brückner wrote:
> Hello!
>
> I'm recompiling my kernel recently to optimize the power usage of my
> laptop (IBM ThinkPad X31). So far, my most efficient kernel at the
> moment is a self-compiled 2.6.22 with phc patches for undervolting,
> suspend2/tuxonice and hrtimers patches to force HPET on my ICH4-M chipset.
>
> Because everyone says, that newer kernel revisions are much more energy
> efficient than my 2.6.22, i tried to compile one to reach at least the
> energy usage of my recent kernel.
> Sadly, this doesn't work because of only one issue:
> With activated wireless networking (atheros chipset with recent madwifi
> driver) i'm losing much energy due to the fact, that my cpu is
> significant more in C2 state than in C3/C4.
Do you have CONFIG_CPU_IDLE enabled? That made a huge difference for me.
Before that was available, _disabling_ CONFIG_NO_HZ also helped when
wifi was enabled (but IIRC made things worse with wifi disabled).
Björn
prev parent reply other threads:[~2008-05-15 22:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-15 21:11 Pascal Brückner
2008-05-15 22:18 ` Björn Steinbrink [this message]
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