Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755739Ab2BWLUQ (ORCPT ); Thu, 23 Feb 2012 06:20:16 -0500 Received: from e23smtp07.au.ibm.com ([202.81.31.140]:49964 "EHLO e23smtp07.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755561Ab2BWLUO (ORCPT ); Thu, 23 Feb 2012 06:20:14 -0500 Date: Thu, 23 Feb 2012 16:50:05 +0530 From: Srivatsa Vaddagiri To: Mike Galbraith Cc: Peter Zijlstra , Suresh Siddha , linux-kernel , Ingo Molnar , Paul Turner Subject: Re: sched: Avoid SMT siblings in select_idle_sibling() if possible Message-ID: <20120223112005.GA7645@linux.vnet.ibm.com> Reply-To: Srivatsa Vaddagiri References: <1321468646.11680.2.camel@sbsiddha-desk.sc.intel.com> <1321495153.5100.7.camel@marge.simson.net> <1321544313.6308.25.camel@marge.simson.net> <1321545376.2495.1.camel@laptop> <1321547917.6308.48.camel@marge.simson.net> <1321551381.15339.21.camel@sbsiddha-desk.sc.intel.com> <1321629267.7080.13.camel@marge.simson.net> <1329748861.2293.345.camel@twins> <1329761661.6276.146.camel@marge.simpson.net> <20120223104959.GA8454@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20120223104959.GA8454@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) x-cbid: 12022301-0260-0000-0000-0000009709AD Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1279 Lines: 40 * Srivatsa Vaddagiri [2012-02-23 16:19:59]: > > Enabling SD_BALANCE_WAKE used to be decidedly too expensive to consider. > > Maybe that has changed, but I doubt it. (general aside: testing with a > > bloated distro config is a big mistake) > > I am seeing 2.6% _improvement_ in volanomark score by enabling SD_BALANCE_WAKE > at SMT/MC domains. Ditto with pipe benchmark. > Machine : 2 Quad-core Intel X5570 CPU (H/T enabled) > Kernel : tip (HEAD at 6241cc8) "perf bench sched pipe" was run 10 times and average ops/sec score alongwith std. dev is noted as below. SD_BALANCE_WAKE SD_BALANCE_WAKE disabled enabled Avg. score 108984.900 111844.300 (+2.6%) std dev 20383.457 21668.604 Note: SD_BALANCE_WAKE for SMT/MC domain was enabled by writing into appropriate flags file present in /proc: # cd /proc/sys/kernel/sched_domain/ # for i in `find . -name flags | grep domain1`; do echo 4671 > $i; done # for i in `find . -name flags | grep domain0`; do echo 703 > $i; done - vatsa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/