From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752761AbXCIWSW (ORCPT ); Fri, 9 Mar 2007 17:18:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752766AbXCIWSV (ORCPT ); Fri, 9 Mar 2007 17:18:21 -0500 Received: from mail33.syd.optusnet.com.au ([211.29.132.104]:44719 "EHLO mail33.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752761AbXCIWSV (ORCPT ); Fri, 9 Mar 2007 17:18:21 -0500 From: Con Kolivas To: Matt Mackall Subject: Re: 2.6.21-rc3-mm1 RSDL results Date: Sat, 10 Mar 2007 09:18:05 +1100 User-Agent: KMail/1.9.5 Cc: linux-kernel , akpm@linux-foundation.org References: <20070309053931.GA10459@waste.org> <20070309213959.GI10394@waste.org> <200703100857.12939.kernel@kolivas.org> In-Reply-To: <200703100857.12939.kernel@kolivas.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200703100918.05547.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Saturday 10 March 2007 08:57, Con Kolivas wrote: > On Saturday 10 March 2007 08:39, Matt Mackall wrote: > > On Sat, Mar 10, 2007 at 08:19:18AM +1100, Con Kolivas wrote: > > > On Saturday 10 March 2007 08:07, Con Kolivas wrote: > > > > On Saturday 10 March 2007 07:46, Matt Mackall wrote: > > > > > My suspicion is the problem lies in giving too much quanta to > > > > > newly-started processes. > > > > > > > > Ah that's some nice detective work there. Mainline does some rather > > > > complex accounting on sched_fork including (possibly) a whole timer > > > > tick which rsdl does not do. make forks off continuously so what you > > > > say may well be correct. I'll see if I can try to revert to the > > > > mainline behaviour in sched_fork (which was obviously there for a > > > > reason). > > > > > > Wow! Thanks Matt. You've found a real bug too. This seems to fix the > > > qemu misbehaviour and bitmap errors so far too! Now can you please try > > > this to see if it fixes your problem? > > > > Sorry, it's about the same. I now suspect an accounting glitch involving > > pipe wake-ups. > > > > 5x memload: good > > 5x execload: good > > 5x forkload: good > > 5 parallel makes: mostly good > > make -j 5: bad > > > > So what's different between makes in parallel and make -j 5? Make's > > job server uses pipe I/O to control how many jobs are running. > > Hmm it must be those deep pipes again then. I removed any quirks testing > for those from mainline as I suspected it would be ok. Guess I"m wrong. I shouldn't blame this straight up though if NO_HZ makes it better. Something else is going wrong... wtf though? -- -ck