Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752807Ab0BSTwW (ORCPT ); Fri, 19 Feb 2010 14:52:22 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:46984 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751614Ab0BSTwV (ORCPT ); Fri, 19 Feb 2010 14:52:21 -0500 Subject: Re: change in sched cpu_power causing regressions with SCHED_MC From: Peter Zijlstra To: Suresh Siddha Cc: Ingo Molnar , LKML , "Ma, Ling" , "Zhang, Yanmin" , "ego@in.ibm.com" , "svaidy@linux.vnet.ibm.com" In-Reply-To: <1266604594.2814.37.camel@sbs-t61.sc.intel.com> References: <1266023662.2808.118.camel@sbs-t61.sc.intel.com> <1266024679.2808.153.camel@sbs-t61.sc.intel.com> <1266057388.557.59599.camel@twins> <1266545807.2909.46.camel@sbs-t61.sc.intel.com> <1266588316.1529.370.camel@laptop> <1266604594.2814.37.camel@sbs-t61.sc.intel.com> Content-Type: text/plain; charset="UTF-8" Date: Fri, 19 Feb 2010 20:52:12 +0100 Message-ID: <1266609132.1529.756.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1044 Lines: 25 On Fri, 2010-02-19 at 10:36 -0800, Suresh Siddha wrote: > > About the ping-pong for the statically infeasible scenario, the problem > > with that is that we actually want to ping-pong a little [*], so we > > might want to look at maybe doing a sd->next_pingpong jiffy measure to > > allow some of that. > > > > [*] I've seen people pretty upset about the fact that when they start 6 > > similar loads on a quad cpu the tasks will not finish in roughly similar > > times. > > I thought we were doing this (ping-ping a little) already. Unless > something broke here also. I thought fix_small_imbalance() takes care of > this too. I'm not sure we do, when I test on the patched kernel I see two distinct groups of runtime appear (haven't checked the unpatched one, but I doubt it'll be better). -- 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/