From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261949AbVHDH3g (ORCPT ); Thu, 4 Aug 2005 03:29:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261943AbVHDH3g (ORCPT ); Thu, 4 Aug 2005 03:29:36 -0400 Received: from ylpvm15-ext.prodigy.net ([207.115.57.46]:471 "EHLO ylpvm15.prodigy.net") by vger.kernel.org with ESMTP id S261949AbVHDH3f (ORCPT ); Thu, 4 Aug 2005 03:29:35 -0400 X-ORBL: [67.117.73.34] Date: Thu, 4 Aug 2005 00:29:16 -0700 From: Tony Lindgren To: Con Kolivas Cc: Jim MacBaine , linux-kernel@vger.kernel.org, ck@vds.kolivas.org, tuukka.tikkanen@elektrobit.com Subject: Re: [PATCH] i386 No-Idle-Hz aka Dynamic-Ticks 3 Message-ID: <20050804072915.GE22000@atomide.com> References: <200508031559.24704.kernel@kolivas.org> <3afbacad05080323596b39e9eb@mail.gmail.com> <200508041704.37026.kernel@kolivas.org> <200508041712.31972.kernel@kolivas.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200508041712.31972.kernel@kolivas.org> User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Con Kolivas [050804 00:16]: > On Thu, 4 Aug 2005 05:04 pm, Con Kolivas wrote: > > On Thu, 4 Aug 2005 04:59 pm, Jim MacBaine wrote: > > > I just borrowed a power meter to see (or not to see) real effects of > > > dyntick. The difference between static 1000 HZ and dynamic HZ is much > > > less than I expected, only a very little about noise. With dyntick > > > disabled at 1000 HZ my laptop needs 31,3 W. With dyntick enabled I > > > get 29.8 W, the pmstats-0.2 script shows me that the system is at > > > 35-45 HZ when it is idle. > > > > > > The power consumption difference between 250 HZ static and dyntick is > > > below the noise, so maybe hardly worth all the struggle. > > > > That's not the point. We want the power savings without sacrificing the > > extra ticks if we need them. > > Oh but thank you very much for confirming the power savings are around the 5% > mark. If we don't measure we won't know (and everything else is mental > masturbation according to Linus ;)). Dyntick on it's own does not do much. But it allows adding better PM code later on. Tony