Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755558Ab1EKPwp (ORCPT ); Wed, 11 May 2011 11:52:45 -0400 Received: from mailout-de.gmx.net ([213.165.64.22]:53855 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752152Ab1EKPwm (ORCPT ); Wed, 11 May 2011 11:52:42 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX18XVXJTR1EXtTeqRU1ZzNVavyCDFy244HyREfWP5C eqC8Pklrff9FTs Subject: Re: [patch 01/15] sched: (fixlet) dont update shares twice on on_rq parent From: Mike Galbraith To: Paul Turner Cc: Hidetoshi Seto , linux-kernel@vger.kernel.org, Peter Zijlstra , Bharata B Rao , Dhaval Giani , Balbir Singh , Vaidyanathan Srinivasan , Srivatsa Vaddagiri , Kamalesh Babulal , Ingo Molnar , Pavel Emelyanov In-Reply-To: References: <20110503092846.022272244@google.com> <20110503092904.541414484@google.com> <4DC8E5C2.9090701@jp.fujitsu.com> <1305016326.14565.2.camel@marge.simson.net> <4DCA40E8.3090805@jp.fujitsu.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 11 May 2011 10:45:49 +0200 Message-ID: <1305103549.14389.6.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2824 Lines: 70 On Wed, 2011-05-11 at 01:13 -0700, Paul Turner wrote: > On Wed, May 11, 2011 at 12:55 AM, Hidetoshi Seto > wrote: > > (2011/05/10 17:32), Mike Galbraith wrote: > >> On Tue, 2011-05-10 at 16:14 +0900, Hidetoshi Seto wrote: > >>> This small fixlet can stand alone. > >>> Peter, how about getting this into git tree first? > >> > >> tip 2f36825b176f67e5c5228aa33d828bc39718811f contains the below. > >> > >> /* Don't dequeue parent if it has other entities besides us */ > >> - if (cfs_rq->load.weight) > >> + if (cfs_rq->load.weight) { > >> + /* > >> + * Bias pick_next to pick a task from this cfs_rq, as > >> + * p is sleeping when it is within its sched_slice. > >> + */ > >> + if (task_sleep && parent_entity(se)) > >> + set_next_buddy(parent_entity(se)); > >> break; > >> + } > >> flags |= DEQUEUE_SLEEP; > >> } > > > > Oh, thanks Mike! > > It seems that this change in tip is better one. > > > > Paul, don't you mind rebasing your patches onto tip/sched/core next time? > > (...or is there better branch for rebase?) > > > > I thought I had but apparently I missed this. > > We still need to set se = parent_entity(se) to avoid the pointless > double update below. > > Will definitely rebase. Wish I could, wouldn't have 114 other patches just to get evaluation tree up to speed :) Index: linux-2.6.32/kernel/sched_fair.c =================================================================== --- linux-2.6.32.orig/kernel/sched_fair.c +++ linux-2.6.32/kernel/sched_fair.c @@ -1308,12 +1308,15 @@ static void dequeue_task_fair(struct rq /* Don't dequeue parent if it has other entities besides us */ if (cfs_rq->load.weight) { + /* Avoid double update below. */ + se = parent_entity(se); + /* * Bias pick_next to pick a task from this cfs_rq, as * p is sleeping when it is within its sched_slice. */ - if (task_sleep && parent_entity(se)) - set_next_buddy(parent_entity(se)); + if (task_sleep && se) + set_next_buddy(se); break; } flags |= DEQUEUE_SLEEP; -- 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/