From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030911AbXDVOgr (ORCPT ); Sun, 22 Apr 2007 10:36:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030915AbXDVOgr (ORCPT ); Sun, 22 Apr 2007 10:36:47 -0400 Received: from mail28.syd.optusnet.com.au ([211.29.133.169]:45831 "EHLO mail28.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030911AbXDVOgq (ORCPT ); Sun, 22 Apr 2007 10:36:46 -0400 From: Con Kolivas To: Willy Tarreau Subject: Re: [ck] Re: [ANNOUNCE] Staircase Deadline cpu scheduler version 0.45 Date: Mon, 23 Apr 2007 00:35:53 +1000 User-Agent: KMail/1.9.5 Cc: ck@vds.kolivas.org, Michael Gerdau , Nick Piggin , Gene Heskett , Al Boldi , Bill Huey , Mike Galbraith , linux kernel mailing list , William Lee Irwin III , Peter Williams , Matt Mackall References: <200704221441.48897.kernel@kolivas.org> <200704222218.32754.kernel@kolivas.org> <20070422142216.GA17210@1wt.eu> In-Reply-To: <20070422142216.GA17210@1wt.eu> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200704230035.54002.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Monday 23 April 2007 00:22, Willy Tarreau wrote: > On Sun, Apr 22, 2007 at 10:18:32PM +1000, Con Kolivas wrote: > > On Sunday 22 April 2007 21:42, Con Kolivas wrote: > > > > Willy I'm still investigating the idle time and fluctuating load as a > > separate issue. Is it possible the multiple ocbench processes are > > naturally synchronising and desynchronising and choosing to sleep and/or > > run at the same time? I can remove the idle time entirely by running > > ocbench at nice 19 which means they are all forced to run at basically > > the same time by the scheduler. > > > > Anyway the more important part is... Can you test this patch please? Dump > > all the other patches I sent you post 045. Michael, if you could test too > > please? > > OK, it's better now. All tasks equally run. Excellent thank you very much (again!) > X is still somewhat jerky, even > at nice -19. I'm sure it happens when it's waiting in the other array. We > should definitely manage to get rid of this if we want to ensure low > latency. Yeah that would be correct. It's clearly possible to keep the whole design philosophy and priority system intact with SD and do away with the arrays if it becomes a continuous stream instead of two arrays but that requires some architectural changes. I've been concentrating on nailing all the remaining issues (and they kept cropping up as you've seen *blush*). However... I haven't quite figured out how to do that architectural change just yet either so let's just iron out all the bugs out of this now. > Just FYI, the idle is often close to zero and the load is often close to > 30, even if still fluctuating : > Hoping this helps ! I can say without a shadow of a doubt it has helped :) I'll respin the patch slightly differently and post it and release as v0.46. > Willy -- -ck