From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757886Ab1KRPMb (ORCPT ); Fri, 18 Nov 2011 10:12:31 -0500 Received: from merlin.infradead.org ([205.233.59.134]:57851 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752181Ab1KRPMa convert rfc822-to-8bit (ORCPT ); Fri, 18 Nov 2011 10:12:30 -0500 Subject: Re: sched: Avoid SMT siblings in select_idle_sibling() if possible From: Peter Zijlstra To: Suresh Siddha Cc: Mike Galbraith , linux-kernel , Ingo Molnar , Paul Turner Date: Fri, 18 Nov 2011 16:12:21 +0100 In-Reply-To: <1321556904.15339.25.camel@sbsiddha-desk.sc.intel.com> References: <1321350377.1421.55.camel@twins> <1321406062.16760.60.camel@sbsiddha-desk.sc.intel.com> <1321435455.5072.64.camel@marge.simson.net> <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> <1321556904.15339.25.camel@sbsiddha-desk.sc.intel.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Evolution 3.0.3- Message-ID: <1321629141.2197.4.camel@twins> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2011-11-17 at 11:08 -0800, Suresh Siddha wrote: > > From: Suresh Siddha > Subject: sched: cleanup domain traversal in select_idle_sibling > > Instead of going through the scheduler domain hierarchy multiple times > (for giving priority to an idle core over an idle SMT sibling in a busy > core), start with the highest scheduler domain with the SD_SHARE_PKG_RESOURCES > flag and traverse the domain hierarchy down till we find an idle group. > > This cleanup also addresses an issue reported by Mike where the recent > changes returned the busy thread even in the presence of an idle SMT > sibling in single socket platforms. > > Signed-off-by: Suresh Siddha > Cc: Mike Galbraith Thanks Suresh!