From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946168Ab2CPX6y (ORCPT ); Fri, 16 Mar 2012 19:58:54 -0400 Received: from forward7.mail.yandex.net ([77.88.61.37]:60607 "EHLO forward7.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1945934Ab2CPX6s (ORCPT ); Fri, 16 Mar 2012 19:58:48 -0400 From: Kirill Tkhai To: Steven Rostedt Cc: "linux-kernel@vger.kernel.org" , Ingo Molnar , Peter Zijlstra In-Reply-To: <944171329661049@web81.yandex.ru> References: <1322774765.8386.2.camel@hp> <20120213172316.GA24145@home.goodmis.org> <944171329661049@web81.yandex.ru> Subject: Re: [PATCH]sched_rt.c: Avoid unnecessary dequeue and enqueue of pushable tasks in set_cpus_allowed_rt() MIME-Version: 1.0 Message-Id: <654301331942324@web109.yandex.ru> Date: Sat, 17 Mar 2012 03:58:44 +0400 X-Mailer: Yamail [ http://yandex.ru ] 5.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=koi8-r Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Steven, what is about the patch from my previous message? Is everything ok? Regards, Kirill 19.02.2012, 18:17, "Kirill Tkhai" : > 13.02.2012, 21:23, "Steven Rostedt" : > >> šI wasn't on the Cc of the original message, but it was bounced to me >> šawhile ago. I'm cleaning out my email and came across it. >> >> šCan you send me the latest version of this patch, either against latest >> šLinus, or against tip/master. >> >> šThanks, >> >> š-- Steve >> >> šP.S. I'll be at ELC this week so it may not get processed right away. > > Migration status depends on a difference of weight from 0 and 1. > If weight > 1 (<= 1) and old weight <= 1 (> 1) then task becomes > pushable (or not pushable). We are not insterested in its exact > values, is it 3 or 4, for example. > > Now if we are changing affinity from a set of 3 cpus to a set of 4, the- > task will be dequeued and enqueued sequentially without important > difference in comparison with initial state. The only difference is in > internal representation of plist queue of pushable tasks and the fact > that the task may won't be the first in a sequence of the same priority > tasks. But it seems to me it gives nothing. > > Signed-off-by: Tkhai Kirill