Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754178Ab3JYNWn (ORCPT ); Fri, 25 Oct 2013 09:22:43 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:35395 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753815Ab3JYNWm (ORCPT ); Fri, 25 Oct 2013 09:22:42 -0400 Message-ID: <526A6FDD.8030501@linux.vnet.ibm.com> Date: Fri, 25 Oct 2013 18:49:25 +0530 From: Preeti U Murthy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120717 Thunderbird/14.0 MIME-Version: 1.0 To: Peter Zijlstra CC: Vaidyanathan Srinivasan , Michael Neuling , Mike Galbraith , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Anton Blanchard , Paul Turner , Ingo Molnar Subject: Re: [PATCH 3/3] sched: Aggressive balance in domains whose groups share package resources References: <20131021114002.13291.31478.stgit@drishya> <20131021114502.13291.60794.stgit@drishya> <20131022222326.GL2490@laptop.programming.kicks-ass.net> In-Reply-To: <20131022222326.GL2490@laptop.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13102513-5140-0000-0000-0000040D7402 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2731 Lines: 90 Hi Peter, On 10/23/2013 03:53 AM, Peter Zijlstra wrote: > On Mon, Oct 21, 2013 at 05:15:02PM +0530, Vaidyanathan Srinivasan wrote: >> kernel/sched/fair.c | 18 ++++++++++++++++++ >> 1 file changed, 18 insertions(+) >> >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c >> index 828ed97..bbcd96b 100644 >> --- a/kernel/sched/fair.c >> +++ b/kernel/sched/fair.c >> @@ -5165,6 +5165,8 @@ static int load_balance(int this_cpu, struct rq *this_rq, >> { >> int ld_moved, cur_ld_moved, active_balance = 0; >> struct sched_group *group; >> + struct sched_domain *child; >> + int share_pkg_res = 0; >> struct rq *busiest; >> unsigned long flags; >> struct cpumask *cpus = __get_cpu_var(load_balance_mask); >> @@ -5190,6 +5192,10 @@ static int load_balance(int this_cpu, struct rq *this_rq, >> >> schedstat_inc(sd, lb_count[idle]); >> >> + child = sd->child; >> + if (child && child->flags & SD_SHARE_PKG_RESOURCES) >> + share_pkg_res = 1; >> + >> redo: >> if (!should_we_balance(&env)) { >> *continue_balancing = 0; >> @@ -5202,6 +5208,7 @@ redo: >> goto out_balanced; >> } >> >> +redo_grp: >> busiest = find_busiest_queue(&env, group); >> if (!busiest) { >> schedstat_inc(sd, lb_nobusyq[idle]); >> @@ -5292,6 +5299,11 @@ more_balance: >> if (!cpumask_empty(cpus)) { >> env.loop = 0; >> env.loop_break = sched_nr_migrate_break; >> + if (share_pkg_res && >> + cpumask_intersects(cpus, >> + to_cpumask(group->cpumask))) > > sched_group_cpus() > >> + goto redo_grp; >> + >> goto redo; >> } >> goto out_balanced; >> @@ -5318,9 +5330,15 @@ more_balance: >> */ >> if (!cpumask_test_cpu(this_cpu, >> tsk_cpus_allowed(busiest->curr))) { >> + cpumask_clear_cpu(cpu_of(busiest), cpus); >> raw_spin_unlock_irqrestore(&busiest->lock, >> flags); >> env.flags |= LBF_ALL_PINNED; >> + if (share_pkg_res && >> + cpumask_intersects(cpus, >> + to_cpumask(group->cpumask))) >> + goto redo_grp; >> + >> goto out_one_pinned; >> } > > Man this retry logic is getting annoying.. isn't there anything saner we > can do? Maybe we can do this just at the SIBLINGS level? Having the hyper threads busy due to the scenario described in the changelog is bad for performance. Regards Preeti U Murthy > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev > -- 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/