From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933339AbcGLOdh (ORCPT ); Tue, 12 Jul 2016 10:33:37 -0400 Received: from foss.arm.com ([217.140.101.70]:59644 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754116AbcGLOdf (ORCPT ); Tue, 12 Jul 2016 10:33:35 -0400 Date: Tue, 12 Jul 2016 15:34:58 +0100 From: Morten Rasmussen To: Peter Zijlstra Cc: mingo@redhat.com, dietmar.eggemann@arm.com, yuyang.du@intel.com, vincent.guittot@linaro.org, mgalbraith@suse.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 11/13] sched/fair: Avoid pulling tasks from non-overloaded higher capacity groups Message-ID: <20160712143458.GK12540@e105550-lin.cambridge.arm.com> References: <1466615004-3503-1-git-send-email-morten.rasmussen@arm.com> <1466615004-3503-12-git-send-email-morten.rasmussen@arm.com> <20160712125953.GP30909@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160712125953.GP30909@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 12, 2016 at 02:59:53PM +0200, Peter Zijlstra wrote: > On Wed, Jun 22, 2016 at 06:03:22PM +0100, Morten Rasmussen wrote: > > @@ -6892,6 +6903,19 @@ static bool update_sd_pick_busiest(struct lb_env *env, > > if (sgs->avg_load <= busiest->avg_load) > > return false; > > > > + if (!(env->sd->flags & SD_ASYM_CPUCAPACITY)) > > + goto asym_packing; > > Does this rely on the 'funny' ASYM_CAP semantics? No, I would actually prefer 'sane' ASYM_CAP semantics. With 'funny' semantics we ended up doing capacity checks inside domain with similar cpus for the lower domain levels which would is pointless and pure overhead. With 'sane' semantics, we only do the check for the domain level where asymmetric capacities are actually observed. > > > + > > + /* Candidate sg has no more than one task per cpu and has > > Tssk, borken comment style. Yes. I will fix that in v3.