From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934391AbaGPO5U (ORCPT ); Wed, 16 Jul 2014 10:57:20 -0400 Received: from wolff.to ([98.103.208.27]:45757 "HELO wolff.to" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1759250AbaGPO5S (ORCPT ); Wed, 16 Jul 2014 10:57:18 -0400 Date: Wed, 16 Jul 2014 09:55:46 -0500 From: Bruno Wolff III To: mingo@redhat.com, peterz@infradead.org Cc: linux-kernel@vger.kernel.org, jwboyer@redhat.com Subject: Scheduler regression from caffcdd8d27ba78730d5540396ce72ad022aff2c Message-ID: <20140716145546.GA6922@wolff.to> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org caffcdd8d27ba78730d5540396ce72ad022aff2c has been causing crashes early in the boot process on one of three machines I have been testing the kernel on. On that one machine it happens every boot. It happens before netconsole is functional. A partial revert of the commit fixes the problem. I do not know why the commit is broken though. I have filed https://bugzilla.kernel.org/show_bug.cgi?id=80251 for this issue. The problem happens on both Fedora and Linus kernels. git diff caffcdd8d27ba78730d5540396ce72ad022aff2c^ caffcdd8d27ba78730d5540396ce72ad022aff2c diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 45d077ed24fb..6340c601475d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5794,8 +5794,6 @@ build_sched_groups(struct sched_domain *sd, int cpu) continue; group = get_group(i, sdd, &sg); - cpumask_clear(sched_group_cpus(sg)); - sg->sgp->power = 0; cpumask_setall(sched_group_mask(sg)); for_each_cpu(j, span) { By rc5 the second line can't be added back because the structure has changed. However adding back cpumask_clear(sched_group_cpus(sg)); to rc5 got things working for me again.