From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750743AbVHHHSf (ORCPT ); Mon, 8 Aug 2005 03:18:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750744AbVHHHSf (ORCPT ); Mon, 8 Aug 2005 03:18:35 -0400 Received: from cantor2.suse.de ([195.135.220.15]:30594 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S1750743AbVHHHSe (ORCPT ); Mon, 8 Aug 2005 03:18:34 -0400 Message-ID: <42F6F0E9.1050606@suse.de> Date: Mon, 08 Aug 2005 07:43:05 +0200 From: Stefan Seyfried User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.10) Gecko/20050715 Thunderbird/1.0.6 Mnenhy/0.7.2.0 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Con Kolivas Cc: tony@atomide.com, ck@vds.kolivas.org, tuukka.tikkanen@elektrobit.com, linux-kernel@vger.kernel.org, tytso@mit.edu Subject: Re: [patch] i386 dynamic ticks 2.6.13-rc4 (code reordered) References: <200508021443.55429.kernel@kolivas.org> <20050806145418.GA16523@thunk.org> <200508070100.55319.kernel@kolivas.org> In-Reply-To: <200508070100.55319.kernel@kolivas.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Con Kolivas wrote: >> When I enabled dynamic tick using: >> >> echo 1 > /sys/devices/system/timer/timer0/dyn_tick_state >> >> The number of ticks dropped down to 60-70 HZ, bus mastering activity >> jumpped up to being almost always active, > > Anyone know why this would happen? This is just a guess, without any actual code-reading: Maybe the C-state decision process just relies on being called every tick, so "after X ticks with no BM activity, go to next deeper C state". As long as 1000 ticks per second are coming in, everything is fine and we enter C[n+1] after X miliseconds without BM activity. Now if there are only 60-70 ticks per second, you never get X ticks without BM activity so you never go deeper than C2. Just a guess. -- Stefan Seyfried \ "I didn't want to write for pay. I QA / R&D Team Mobile Devices \ wanted to be paid for what I write." SUSE LINUX Products GmbH, Nürnberg \ -- Leonard Cohen