From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755259Ab3BEIZd (ORCPT ); Tue, 5 Feb 2013 03:25:33 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:52959 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751426Ab3BEIZa (ORCPT ); Tue, 5 Feb 2013 03:25:30 -0500 Message-ID: <5110C1E7.9020106@huawei.com> Date: Tue, 5 Feb 2013 16:25:11 +0800 From: Honghui Zhang User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130107 Thunderbird/17.0.2 MIME-Version: 1.0 To: Kirill Tkhai CC: Steven Rostedt , , Ingo Molnar , Peter Zijlstra , linux-rt-users Subject: Re: [PATCH] sched/rt: Decrease number of calls of push_rt_task() in push_rt_tasks() References: <500221360048944@web26g.yandex.ru> In-Reply-To: <500221360048944@web26g.yandex.ru> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.135.72.168] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2013/2/5 15:22, Kirill Tkhai wrote: >> >> Suppose we have a large number of cpus(say 4096), with the last one running >> a low-priority task on it. Is it possible with this patch we will never reach >> the last cpu in case that previous cpu has complete the pulled task? > > Yes. But this patch is about several pushable tasks on the same cpu. > > Kirill > Maybe I haven't make myself understood, but in that case, there will be a higher-priority task in the runqueue of the pushing cpu, and a lower-priority task running in the last cpu which could not be preempt by push_rt_task(), I don't think it's acceptable. Hans