From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753386AbcITTlR (ORCPT ); Tue, 20 Sep 2016 15:41:17 -0400 Received: from mail-yw0-f195.google.com ([209.85.161.195]:33109 "EHLO mail-yw0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753056AbcITTlM (ORCPT ); Tue, 20 Sep 2016 15:41:12 -0400 Date: Tue, 20 Sep 2016 15:41:09 -0400 From: Tejun Heo To: yingooyim Cc: lizefan@huawei.com, hannes@cmpxchg.org, cgroups@vger.kernel.org, LKML , jinh@konkuk.ac.kr Subject: Re: [PATCH] cgroup/cpu: Fix tg_has_rt_task() malfunction Message-ID: <20160920194109.GC17513@htj.duckdns.org> References: <1474208588556845.0.mail@mail> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1474208588556845.0.mail@mail> User-Agent: Mutt/1.7.0 (2016-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 18, 2016 at 11:23:10PM +0900, yingooyim wrote: > Hi, > I am a graduate student of System Software Lab. at Konkuk University > (http://sslab.konkuk.ac.kr). > > This patch is to fix the malfunction of tg_has_rt_tasks(). The > tg_has_rt_tasks() function is supposed to determine whether a task > group includes an "rt task" or not. However, it returns true for > "dl task" too. The origin of this problem is that rt_task() called > by tg_has_rt_tasks() returns true for dl tasks. Because of this > problem, tg_rt_schedulable() that calls tg_has_rt_tasks() returns > –EBUSY if we try to initialize an rt task group, while a dl task > is running. That is, you cannot run an rt task group when there > exists a dl task in the system. Our patch provided in this post > simply makes the tg_has_rt_tasks() function return false for dl > tasks by calling dl_task() in the conditional statement. > > Previously we have provided another patch for rt_task() (more > precisely rt_prio()) to resolve this problem as follows: > https://patchwork.kernel.org/patch/9299267/ > However, a dependency issue were raised. So, we think that it is > better to modify tg_has_rt_tasks() instead of rt_task() itself. > > Signed-off-by: Yin-goo Yim Can you please repost with scheduler maintainers cc'd? Ingo Molnar Peter Zijlstra Thanks. -- tejun