From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933148AbZJMJkM (ORCPT ); Tue, 13 Oct 2009 05:40:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755865AbZJMJkL (ORCPT ); Tue, 13 Oct 2009 05:40:11 -0400 Received: from mail.gmx.net ([213.165.64.20]:43199 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754623AbZJMJkK (ORCPT ); Tue, 13 Oct 2009 05:40:10 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1/Cma06nwHC9c39qYH2jpZhOUmoM8lxTub3bPvZoz SOcwCyt33ANSfb Subject: Re: hackbench regression with kernel 2.6.32-rc1 From: Mike Galbraith To: "Zhang, Yanmin" Cc: Peter Zijlstra , LKML , Ingo Molnar In-Reply-To: <1255403522.3684.57.camel@ymzhang> References: <1255079943.25078.23.camel@ymzhang> <1255084986.8802.46.camel@laptop> <1255331120.3684.43.camel@ymzhang> <1255357264.10420.15.camel@twins> <1255403522.3684.57.camel@ymzhang> Content-Type: text/plain Date: Tue, 13 Oct 2009 11:39:00 +0200 Message-Id: <1255426740.9958.95.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1.1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 X-FuHaFi: 0.54 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2009-10-13 at 11:12 +0800, Zhang, Yanmin wrote: > NEXT_BUDDY has no help on volanoMark and tbench. Vmark is mostly about preemption and affinity. Increases in wakeup preemption or load balancing will bring it down. The affinity bit applies heavily to mysql+oltp too, though it loves wakeup preemption. test test test... My conclusion for results _here_ is load balancing changes are harming cache wise. GENTLE_FAIR_SLEEPERS harms short term fairness, but despite GENTLE_FAIR_SLEEPERS, we're still wakeup preempting too much, likely doing more cache harm. (even for the desktop, overly aggressive wakeup preemption can do harm) I'd suggest trying the settings below. vmark 92143 stock settings 96396 -SD_BALANCE_NEWIDLE 99403 -SD_WAKE_BALANCE 121821 min_granularity+wakeup_granularity *= 2 128795 NO_WAKEUP_PREEMPT (and back on, just checking fairness) 97193 NO_FAIR_SLEEPERS (vmark likes fairness, max out fairness) 107519 FAIR_SLEEPERS NO_GENTLE_FAIR_SLEEPERS (over-preempt again, so..) 123721 min_granularity+wakeup_granularity *= 2 131290 NO_WAKEUP_PREEMPT (and back on, just checking fairness) 123464 NEXT_BUDDY (no effect) vs stock 1.339 tbench 8 with these settings. 752.249 MB/sec 8 procs 747.010 MB/sec 8 procs NO_NEXT_BUDDY 753.177 MB/sec 8 procs min_granularity+wakeup_granularity /= 2 749.518 MB/sec 8 procs GENTLE_FAIR_SLEEPERS 753.051 MB/sec 8 procs min_granularity+wakeup_granularity /= 2 734.772 MB/sec 8 procs +SD_WAKE_BALANCE 733.683 MB/sec 8 procs +SD_BALANCE_NEWIDLE (we are at stock) vs stock 1.025 Turns off netfilter, stock settings 903.304 MB/sec 8 procs 900.656 MB/sec 8 procs -SD_BALANCE_NEWIDLE 928.914 MB/sec 8 procs -SD_WAKE_BALANCE 930.591 MB/sec 8 procs min_granularity+wakeup_granularity *= 2 926.836 MB/sec 8 procs NO_GENTLE_FAIR_SLEEPERS 931.148 MB/sec 8 procs min_granularity+wakeup_granularity *= 2 vs stock 1.030 vmark 146264 116559 stock vs stock 1.254