From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965584AbXDVJRw (ORCPT ); Sun, 22 Apr 2007 05:17:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965589AbXDVJRw (ORCPT ); Sun, 22 Apr 2007 05:17:52 -0400 Received: from 1wt.eu ([62.212.114.60]:2177 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965565AbXDVJRv (ORCPT ); Sun, 22 Apr 2007 05:17:51 -0400 Date: Sun, 22 Apr 2007 11:14:51 +0200 From: Willy Tarreau To: Con Kolivas Cc: linux kernel mailing list , ck list , Ingo Molnar , Mike Galbraith , Al Boldi , Peter Williams , Nick Piggin , Matt Mackall , Bill Huey , William Lee Irwin III , Gene Heskett Subject: Re: [ANNOUNCE] Staircase Deadline cpu scheduler version 0.45 Message-ID: <20070422091451.GA15913@1wt.eu> References: <200704221441.48897.kernel@kolivas.org> <200704221731.58724.kernel@kolivas.org> <20070422080607.GA15411@1wt.eu> <200704221853.59358.kernel@kolivas.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200704221853.59358.kernel@kolivas.org> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 22, 2007 at 06:53:58PM +1000, Con Kolivas wrote: > On Sunday 22 April 2007 18:06, Willy Tarreau wrote: > > On Sun, Apr 22, 2007 at 05:31:58PM +1000, Con Kolivas wrote: > > > On Sunday 22 April 2007 17:27, Con Kolivas wrote: > > > > On Sunday 22 April 2007 17:00, Willy Tarreau wrote: > > > > > On Sun, Apr 22, 2007 at 02:41:48PM +1000, Con Kolivas wrote: > > > > > > A significant bugfix for SMP balancing was just posted for the > > > > > > staircase deadline cpu scheduler which improves behaviour > > > > > > dramatically on any SMP machine. > > > > > > > > > > > > Thanks to Willy Tarreau for noticing likely fault point. > > > > > > > > > > > > Also requested was a version in the Makefile so this version of the > > > > > > patch adds -sd045 to the kernel version. > > > > > > > > > > Con, I'm sorry, but it is worse with this one :-( > > > > > > > > Well that was quick testing, thanks. > > > > > > > > > The lag when typing in xterms is even more noticeable and vmstat > > > > > output oscillates between 8 and 65, with idle rates around 50%, as > > > > > you can see below : > > > > > > > > > > Renicing X or not does not change anything here. > > > > > > > > > > I suspect that the bug you fixed was hiding another one :-/ > > > > > If you want me to test another patch, feel free to ask. > > > > > > Just as a debug point could you please try this patch? Thanks. > > > > OK, this time, the ocbench took ages to start. They appeared immediately > > but very few of them (less than 8 out of 64) really started to work. The > > system remained very responsive and smooth during the test. But I guess > > I know why : all the load was sent to CPU 0 : > > Shouldn't have affected smp balancing at all, but try this on top of the > ontop please? Thanks Does not change anything. There clearly is a huge regression somewhere :-/ The second CPU is not used by ocbench, and again, out of 64 tasks, only a small bunch (between 4 and 8) do something. Con, you should review the changes between 0.44 and 0.45, I think you introduced a bug which broke fairness while fixing another one. Willy