From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755128AbcGEMsf (ORCPT ); Tue, 5 Jul 2016 08:48:35 -0400 Received: from forward-corp1f.mail.yandex.net ([95.108.130.40]:55382 "EHLO forward-corp1f.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752126AbcGEMs3 (ORCPT ); Tue, 5 Jul 2016 08:48:29 -0400 Authentication-Results: smtpcorp1m.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Subject: Re: [PATCH] sched/core: really pretend early bootup to be a normal task To: Peter Zijlstra References: <146771780366.86926.5349525389994177302.stgit@buzz> <20160705124129.GB30921@twins.programming.kicks-ass.net> Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Sasha Levin , Yao Dongdong From: Konstantin Khlebnikov Message-ID: <577BAC73.1080403@yandex-team.ru> Date: Tue, 5 Jul 2016 15:47:47 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <20160705124129.GB30921@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05.07.2016 15:41, Peter Zijlstra wrote: > On Tue, Jul 05, 2016 at 02:23:23PM +0300, Konstantin Khlebnikov wrote: >> Commit 1b537c7d1e58 ("sched/core: Remove check of p->sched_class") placed >> "current->sched_class = &fair_sched_class" before call of init_idle() which >> immediately set sched_class back to idle_sched_class. >> >> This patch reverts this piece because after commit de9b8f5dcbd9 ("sched: >> Fix crash trying to dequeue/enqueue the idle thread") init_idle() doesn't >> call do_set_cpus_allowed() and nobody will dereference ->sched_class. > > I don't understand, what is broken? > "pretending" hack is broken. As I wrote maybe it is not needed any more. -- Konstantin