Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760383AbZCYNLX (ORCPT ); Wed, 25 Mar 2009 09:11:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754995AbZCYNLO (ORCPT ); Wed, 25 Mar 2009 09:11:14 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:40631 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754428AbZCYNLN (ORCPT ); Wed, 25 Mar 2009 09:11:13 -0400 Date: Wed, 25 Mar 2009 14:10:46 +0100 From: Ingo Molnar To: Gautham R Shenoy Cc: Peter Zijlstra , Vaidyanathan Srinivasan , linux-kernel@vger.kernel.org, Suresh Siddha , Balbir Singh , Nick Piggin , Dhaval Giani , Bharata B Rao Subject: Re: [RFC PATCH 11/11] sched: Add comments to find_busiest_group() function. Message-ID: <20090325131046.GF516@elte.hu> References: <20090325091239.13992.96090.stgit@sofia.in.ibm.com> <20090325091427.13992.18933.stgit@sofia.in.ibm.com> <20090325114314.GC11302@in.ibm.com> <20090325122913.GA28639@elte.hu> <20090325130738.GD11302@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090325130738.GD11302@in.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2333 Lines: 60 * Gautham R Shenoy wrote: > On Wed, Mar 25, 2009 at 01:29:13PM +0100, Ingo Molnar wrote: > > > > * Gautham R Shenoy wrote: > > > > > On Wed, Mar 25, 2009 at 02:44:27PM +0530, Gautham R Shenoy wrote: > > > > Add /** style comments around find_busiest_group(). Also add a few explanatory > > > > */ > > > > > > > > > > > > > static struct sched_group * > > > > find_busiest_group(struct sched_domain *sd, int this_cpu, > > > > @@ -3593,17 +3613,31 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, > > > > update_sd_lb_stats(sd, this_cpu, idle, sd_idle, cpus, > > > > balance, &sds); > > > > > > > > + /* Cases where imbalance does not exist from POV of this_cpu */ > > > > + /* 1) this_cpu is not the appropriate cpu to perform load balancing > > > > + * at this level. > > > > + * 2) There is no busy sibling group to pull from. > > > > + * 3) This group is the busiest group. > > > > + * 4) This group is more busy than the avg busieness at this > > > > + * sched_domain. > > > > + * 5) The imbalance is within the specified limit. > > > > + * 6) Any rebalance would lead to ping-pong > > > > + */ > > > > if (balance && !(*balance)) > > > > goto ret; > > > > > > > > - if (!sds.busiest || sds.this_load >= sds.max_load > > > > - || sds.busiest_nr_running == 0) > > > > + if (!sds.busiest || sd.busiest_nr_running == 0) > > > ^^^^^^^^^^^^^^^^^^^^ > > > should have been sds.busiest_nr_running. Hence the build failure on tip. > > > > > > I think I missed compile testing this last patch. > > > > > > Ingo, could you revert commit 7b6340ef884aff69a54f8a530c73ad9da0a7c388 in > > > tip/balancing and commit the following patch instead? > > > > sure - i've amended it and started testing it locally. If it passes > > testing it should show up in tip:master. > > Thanks! > > Meanwhile I'll see if there are any regressions in 2.6.29 with > this patchset. Just try tip:master please - there's a number of other scheduler changes and it would be nice to validate them together. Ingo -- 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/