From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4BF29C4321D for ; Wed, 22 Aug 2018 16:33:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED28A2075B for ; Wed, 22 Aug 2018 16:33:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ED28A2075B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727150AbeHVT6x (ORCPT ); Wed, 22 Aug 2018 15:58:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:45888 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726786AbeHVT6w (ORCPT ); Wed, 22 Aug 2018 15:58:52 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2C1CA206B7; Wed, 22 Aug 2018 16:33:17 +0000 (UTC) Date: Wed, 22 Aug 2018 12:33:15 -0400 From: Steven Rostedt To: Mike Galbraith Cc: Thomas Gleixner , Sebastian Andrzej Siewior , Julia Cartwright , linux-rt-users , LKML Subject: Re: [BUG v4.14-rt] kernel BUG at /work/rt/stable-rt.git/kernel/sched/core.c:1639! Message-ID: <20180822123315.3a184f9c@gandalf.local.home> In-Reply-To: <20180822121749.5c4632d7@gandalf.local.home> References: <20180817162340.6e8482fd@gandalf.local.home> <1534588142.2516.10.camel@gmx.de> <1534597992.15909.17.camel@gmx.de> <1534660115.6187.4.camel@gmx.de> <20180822121749.5c4632d7@gandalf.local.home> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sebastian, On Wed, 22 Aug 2018 12:17:49 -0400 Steven Rostedt wrote: > On Sun, 19 Aug 2018 08:28:35 +0200 > Mike Galbraith wrote: > > > On Sat, 2018-08-18 at 15:13 +0200, Mike Galbraith wrote: > > > seems it has be something from the 4.17 cycle that went back to 4.14- > > > stable after 4.1[56]-stable trees went extinct. > > > > See ("sched/core: Require cpu_active() in select_task_rq(), for user tasks") > > > > Fix it like so? > > > > sched: Allow pinned user tasks to be awakened to the CPU they pinned > > > > Since 7af443ee16976, select_fallback_rq() will BUG() if the CPU to > > which a task has pinned itself and pinned becomes !cpu_active() > > while it slept. Serving a 10 megaton eviction notice is neither > > helpful nor required, the task will migrate when it can do so. > > This seems to fix the issue that I was seeing. Thanks! > > I'll add this to my repo as well. I'm going to hold off on pulling this in until I see it in your tree, because a stable RT branch should not carry anything that isn't in the head RT tree. And it appears that this can affect your repo too. -- Steve > > > > > Signed-off-by: Mike Galbraith > > --- > > kernel/sched/core.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > --- a/kernel/sched/core.c > > +++ b/kernel/sched/core.c > > @@ -980,7 +980,7 @@ static inline bool is_cpu_allowed(struct > > if (!cpumask_test_cpu(cpu, p->cpus_ptr)) > > return false; > > > > - if (is_per_cpu_kthread(p)) > > + if (is_per_cpu_kthread(p) || __migrate_disabled(p)) > > return cpu_online(cpu); > > > > return cpu_active(cpu); >