From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261496AbVHBLcM (ORCPT ); Tue, 2 Aug 2005 07:32:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261495AbVHBLcM (ORCPT ); Tue, 2 Aug 2005 07:32:12 -0400 Received: from ylpvm12-ext.prodigy.net ([207.115.57.43]:47272 "EHLO ylpvm12.prodigy.net") by vger.kernel.org with ESMTP id S261505AbVHBLbw (ORCPT ); Tue, 2 Aug 2005 07:31:52 -0400 X-ORBL: [67.117.73.34] Date: Tue, 2 Aug 2005 04:31:38 -0700 From: Tony Lindgren To: Con Kolivas Cc: Lee Revell , linux-kernel@vger.kernel.org, tuukka.tikkanen@elektrobit.com, ck@vds.kolivas.org Subject: Re: [patch] i386 dynamic ticks 2.6.13-rc4 (code reordered) Message-ID: <20050802113137.GK15903@atomide.com> References: <200508021443.55429.kernel@kolivas.org> <200508021739.20347.kernel@kolivas.org> <20050802081512.GI15903@atomide.com> <200508022054.22276.kernel@kolivas.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200508022054.22276.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 [050802 03:54]: > On Tue, 2 Aug 2005 18:15, Tony Lindgren wrote: > > * Con Kolivas [050802 00:36]: > > > On Tue, 2 Aug 2005 05:17 pm, Tony Lindgren wrote: > > > > But this you can verify by booting to single user mode and then running > > > > pmstats 5, and if ticks is not below 25HZ, there's something in the > > > > kernel polling. > > > > > > I'm removing modules and they don't seem to do anything so I'm not sure > > > what else to try. > > > > If you have 130HZ in single user mode, it's some kernel driver. > > You could printk the the next timer, then grep for that in System.map: > > I kept pulling modules and eventually got to 27Hz so something was definitely > happening. Cool. > I need to ask you why you think limiting the maximum Hz is a bad idea? On a > laptop, say we have set the powersave governor, we have already told the > kernel we are interested in maximising power saving at the expense of > performance. Would it not be appropriate for this to be linked in a way that > sets maximum Hz to some value that maximises power save (whatever that value > is) at that time? With dyntick the system will run at max HZ only when busy. It is possible that cutting down max HZ might cause some savings while busy, but I would assume the savings are minimal. I personally prefer to have the performance available when needed, and max savings while idle. Tony