From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752665AbXCWCds (ORCPT ); Thu, 22 Mar 2007 22:33:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750878AbXCWCds (ORCPT ); Thu, 22 Mar 2007 22:33:48 -0400 Received: from smtp110.mail.mud.yahoo.com ([209.191.85.220]:24136 "HELO smtp110.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752665AbXCWCdr (ORCPT ); Thu, 22 Mar 2007 22:33:47 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:X-YMail-OSG:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=PfLb09qaaviCz884nV70rBTP8qpPrs86o2+qRVGxqI0PyYYFEj+dMj3olY4t/Pw4V8zhqWiK2w9LsTBuY4UDSC9ZiztnyPUqcVoldeg4GPWha3uEXF94JawgXhDLlNnsjJJpw4/IYNtxxeN9dBHXXKd0FsPSf+yTMB2hQnQhgW8= ; X-YMail-OSG: OP2kaFcVM1nsldvcL8oEzloI2PPLToHCADqJ21kp2h0Biu7385cCZru6ZgeT8NnaSpeVzJW8FCqaROqq1Odd5na5UykQ3OztYo2CLEOIVAOE7DWmIFQNR7jI7wkqmwEzu8Mhb_.y4_syIEA- Message-ID: <46033C85.2010008@yahoo.com.au> Date: Fri, 23 Mar 2007 13:33:41 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Al Boldi CC: linux-kernel@vger.kernel.org Subject: Re: [patch] 2.6.21-rc4 nicksched v32 References: <200703221740.47801.a1426z@gawab.com> In-Reply-To: <200703221740.47801.a1426z@gawab.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Al Boldi wrote: > Nick Piggin wrote: >>Timeslices get scaled by /proc/sys/kernel/base_timeslice. If you have bad >>interactivity you could try lowering this and see if it helps. > > > As I am on 2.6.20, I can't really test this patch, but I tried your sched > from PlugSched and its not bad. OK, the one in plugsched is reasonably different... > I'm getting strange numbers with chew.c, though. Try this: > Boot into /bin/sh > Run ./chew on one console. > Run ./chew on another console. > Watch latencies. > > Console 1: > pid 671, prio 0, out for 799 ms, ran for 800 ms, load 50% > pid 671, prio 0, out for 799 ms, ran for 801 ms, load 50% > pid 671, prio 0, out for 799 ms, ran for 799 ms, load 49% > pid 671, prio 0, out for 800 ms, ran for 800 ms, load 49% > > Console 2: > pid 672, prio 0, out for 800 ms, ran for 799 ms, load 49% > pid 672, prio 0, out for 799 ms, ran for 800 ms, load 50% > pid 672, prio 0, out for 799 ms, ran for 800 ms, load 50% > pid 672, prio 0, out for 799 ms, ran for 799 ms, load 49% > pid 672, prio 0, out for 799 ms, ran for 799 ms, load 49% > > Looks good, but now add a cpu-hog, ie. while :; do :; done > > Console 1: > > pid 671, prio 0, out for 799 ms, ran for 399 ms, load 33% > pid 671, prio 0, out for 799 ms, ran for 399 ms, load 33% > pid 671, prio 0, out for 799 ms, ran for 399 ms, load 33% > pid 671, prio 0, out for 799 ms, ran for 399 ms, load 33% > > Console 2: > pid 672, prio 0, out for 1599 ms, ran for 799 ms, load 33% > pid 672, prio 0, out for 1599 ms, ran for 799 ms, load 33% > pid 672, prio 0, out for 1599 ms, ran for 800 ms, load 33% > pid 672, prio 0, out for 1599 ms, ran for 799 ms, load 33% > > It's smooth, but latencies are double on console2. Easy enough to fix, > though, just press scrollock to induce a sleep and then release. Yeah, this issue is since fixed in v32. > Also, latencies are huge. Is there a way to fix latencies per nice? Latencies should be quite a bit lower in v32. You can lower it with /proc/sys/kernel/base_timeslice, however I would like to see whether the current setting gives reasonable interactivity. Thanks, Nick -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com