From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752909AbbFEHTn (ORCPT ); Fri, 5 Jun 2015 03:19:43 -0400 Received: from casper.infradead.org ([85.118.1.10]:50937 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751074AbbFEHTk (ORCPT ); Fri, 5 Jun 2015 03:19:40 -0400 Date: Fri, 5 Jun 2015 09:19:31 +0200 From: Peter Zijlstra To: pang.xunlei@zte.com.cn Cc: juri.lelli@gmail.com, ktkhai@parallels.com, linux-kernel@vger.kernel.org, mingo@elte.hu, oleg@redhat.com, pang.xunlei@linaro.org, rostedt@goodmis.org, umgwanakikbuti@gmail.com Subject: Re: [RFC][PATCH 1/7] sched: Replace post_schedule with a balance callback list Message-ID: <20150605071931.GB19282@twins.programming.kicks-ass.net> References: <20150601135818.506080835@infradead.org> <20150601140839.630055365@infradead.org> <20150603085527.GA3644@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 05, 2015 at 03:13:38PM +0800, pang.xunlei@zte.com.cn wrote: > > It will make sched_setscheduler() etc.. a little more expensive, but > > that doesn't matter, those are not critical things at all. > > Another side effect it may have is that it will introduce some latency, > because we have to wait for next schedule() point to do the balancing. > prio_changed_rt()->pull_rt_task() is not rare cases when using PI futex. See patch 3, that adds the balance_callback() to sched_setscheduler() and rt_mutex_setprio() to avoid just that.