From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756126AbZBKCJt (ORCPT ); Tue, 10 Feb 2009 21:09:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752728AbZBKCJi (ORCPT ); Tue, 10 Feb 2009 21:09:38 -0500 Received: from mga12.intel.com ([143.182.124.36]:36942 "EHLO azsmga102.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750920AbZBKCJh (ORCPT ); Tue, 10 Feb 2009 21:09:37 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.38,188,1233561600"; d="scan'208";a="109381210" Subject: Re: [PATCH 0/2] fix the itimer regression (BZ 12618) From: "Zhang, Yanmin" To: Peter Zijlstra Cc: Ingo Molnar , Lin Ming , Mike Galbraith , "tglx@linutronix.de" , "oleg@redhat.com" , "linux-kernel@vger.kernel.org" , "seto.hidetoshi@jp.fujitsu.com" In-Reply-To: <1234270044.23438.7.camel@twins> References: <20090205112414.104100700@chello.nl> <20090205120608.GB8799@elte.hu> <1233895919.2604.323.camel@ymzhang> <20090206151832.GL18368@elte.hu> <1234161961.5991.41.camel@minggr.sh.intel.com> <20090209214723.GA2664@elte.hu> <1234270044.23438.7.camel@twins> Content-Type: text/plain Date: Wed, 11 Feb 2009 10:09:08 +0800 Message-Id: <1234318148.2604.370.camel@ymzhang> Mime-Version: 1.0 X-Mailer: Evolution 2.22.1 (2.22.1-2.fc9) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2009-02-10 at 13:47 +0100, Peter Zijlstra wrote: > On Mon, 2009-02-09 at 22:47 +0100, Ingo Molnar wrote: > > * Lin Ming wrote: > > > > > On Fri, 2009-02-06 at 23:18 +0800, Ingo Molnar wrote: > > > > * Zhang, Yanmin wrote: > > > > > > > > > On Thu, 2009-02-05 at 13:06 +0100, Ingo Molnar wrote: > > > > > > * Peter Zijlstra wrote: > > > > > > > > > > > > > This should hopefully address all the itimer borkage. > > > > > > > > > > > > Applied to tip:timers/urgent, thanks Peter! > > > > > > > > > > > > Yanmin: could you check hacbench_pth with latest tip/master, do > > > > > > these fixes resolve that 3% regression you reported? > > > > > > > > > > Lin Ming tested it and hackbench_pth/volanoMark regression all disappear. > > > > > But oltp has a regression. We think oltp new regression isn't related to > > > > > the patch. Ming is investigating it. > > > > > > > > Potential suspects for oltp regression would be: > > > > > > > > 3d39870: sched_rt: don't use first_cpu on cpumask created with cpumask_and > > > > a571bbe: sched: fix buddie group latency > > > > a9f3e2b: sched: clear buddies more aggressively > > > > 1596e29: sched: symmetric sync vs avg_overlap > > > > d942fb6: sched: fix sync wakeups > > > > > > I tested the latest tip-master branch. > > > After reverting "d942fb6: sched: fix sync wakeups", the oltp regression > > > on the 8cores Stockley machine is mostly fixed. > > > > > > On another 4*4 cores Tigerton machine, oltp has more than 10% regression > > > with 2.6.29-rc4 compared with 2.6.29-rc3. > > > > ok, that commit needs fixed or reverted. Peter, Mike? > > Yanmin, is that tigerton regression also due to the sync changes? Yes. > > That is, if you revert both d942fb6 and 1596e29, does it get back to > -rc3 state, Yes. > or is the tigerton regression due to something else? > This isn't quite clear to me. > > Ingo, if that is the case, I'm fine with reverting those changes for > now, and have another look at them later on -- preferably when someone > ships me a 4*4 machine so I can validate :-) 2*4 stoakley has the similiar regression. To find potential scalability issues, I run sysbench+mysql(oltp) with many thread numbers, such like 8,12,16,32,64,128, then get an average value. yanmin