From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934767AbYEIBR4 (ORCPT ); Thu, 8 May 2008 21:17:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755727AbYEIBRp (ORCPT ); Thu, 8 May 2008 21:17:45 -0400 Received: from mga09.intel.com ([134.134.136.24]:46851 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756251AbYEIBRn (ORCPT ); Thu, 8 May 2008 21:17:43 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.27,457,1204531200"; d="scan'208";a="326151136" Subject: Re: sysbench+mysql(oltp, readonly) 30% regression with 2.6.26-rc1 From: "Zhang, Yanmin" To: Peter Zijlstra Cc: Mike Galbraith , LKML , Ingo Molnar In-Reply-To: <1210238622.13978.193.camel@twins> References: <1210136148.3453.59.camel@ymzhang> <1210177575.6525.4.camel@lappy.programming.kicks-ass.net> <1210228531.3453.124.camel@ymzhang> <1210233617.4895.6.camel@marge.simson.net> <1210237267.3453.143.camel@ymzhang> <1210238114.11887.3.camel@marge.simson.net> <1210238622.13978.193.camel@twins> Content-Type: text/plain; charset=UTF-8 Date: Fri, 09 May 2008 09:16:19 +0800 Message-Id: <1210295779.3453.155.camel@ymzhang> Mime-Version: 1.0 X-Mailer: Evolution 2.21.5 (2.21.5-2.fc9) Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2008-05-08 at 11:23 +0200, Peter Zijlstra wrote: > On Thu, 2008-05-08 at 11:15 +0200, Mike Galbraith wrote: > > On Thu, 2008-05-08 at 17:01 +0800, Zhang, Yanmin wrote: > > > On Thu, 2008-05-08 at 10:00 +0200, Mike Galbraith wrote: > > > > > > Hm. I was doing some sysbench+postgress(oltp, ro) testing on my little > > > > Q6600 box this morning, and saw a different picture. > > > > > How many cpu are in the Q6600? > > > > 1. > > > > > > > > > > In attached pdf, .bkl refers to Linus' BKL patch, .weight is the weight > > > > fix, both are applied to git.today. The script I used is also attached. > > > With my 8-core stoakley (using mysql): > > > 1) 2.6.25: > > > Number of threads: 6 > > > read/write requests: 8025024 (66874.53 per sec.) > > > Number of threads: 8 > > > read/write requests: 9132816 (76106.14 per sec.) > > > Number of threads: 10 > > > read/write requests: 9244998 (77040.75 per sec.) > > > Number of threads: 12 > > > read/write requests: 8994174 (74950.36 per sec.) > > > Number of threads: 14 > > > read/write requests: 9051322 (75426.54 per sec.) > > > Number of threads: 16 > > > read/write requests: 9015412 (75126.93 per sec.) > > > > > > 2) 2.6.26-rc1: > > > Number of threads: 6 > > > read/write requests: 5754056 (47949.87 per sec.) > > > Number of threads: 8 > > > read/write requests: 6528480 (54403.29 per sec.) > > > Number of threads: 10 > > > read/write requests: 6444690 (53705.16 per sec.) > > > Number of threads: 12 > > > read/write requests: 6544258 (54534.23 per sec.) > > > Number of threads: 14 > > > read/write requests: 6796650 (56637.65 per sec.) > > > Number of threads: 16 > > > read/write requests: 6718110 (55983.18 per sec.) > > > > > > 3) 2.6.26-rc1+weight > > > Number of threads: 16 > > > read/write requests: 3219076 (26824.22 per sec.) > > > > > > I'm not sure if more cpu could introduce more contention in this test. > > > > -rc1. Do you have the fix below applied? > > Oooh - good catch, that seems to be a post -rc1 merge. > > Yes this is required. With below patch+previous_fix_weight_calc, the result is improved, but is still about 10% worse than the one of pure 2.6.26-rc1. Number of threads: 16 read/write requests: 6104336 (50867.11 per sec.) > > > commit a992241de614dd2b7c97a9ba64e28c0e563f19bf > > Author: Peter Zijlstra > > Date: Mon May 5 23:56:17 2008 +0200 > > > > sched: fix normalized sleeper > > > > Normalized sleeper uses calc_delta*() which requires that the rq load is > > already updated, so move account_entity_enqueue() before place_entity() > > > > Tested-by: Frans Pop > > Signed-off-by: Peter Zijlstra > > Signed-off-by: Ingo Molnar > > > > diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c > > index 89fa32b..1295ddc 100644 > > --- a/kernel/sched_fair.c > > +++ b/kernel/sched_fair.c > > @@ -682,6 +682,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) > > * Update run-time statistics of the 'current'. > > */ > > update_curr(cfs_rq); > > + account_entity_enqueue(cfs_rq, se); > > > > if (wakeup) { > > place_entity(cfs_rq, se, 0); > > @@ -692,7 +693,6 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) > > check_spread(cfs_rq, se); > > if (se != cfs_rq->curr) > > __enqueue_entity(cfs_rq, se); > > - account_entity_enqueue(cfs_rq, se); > > } > > > > static void update_avg(u64 *avg, u64 sample) > > > > >