linux-kernel - Re: Strange C3/C4 sleep state behaviour

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20080515221803.GA17259@atjola.homenet>
Date:	Fri, 16 May 2008 00:18:03 +0200
From:	Björn Steinbrink <B.Steinbrink@....de>
To:	Pascal Brückner <pascal_2001@....de>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Strange C3/C4 sleep state behaviour

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
--
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/