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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF974C433EF for ; Thu, 7 Apr 2022 10:52:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244567AbiDGKyi (ORCPT ); Thu, 7 Apr 2022 06:54:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232029AbiDGKyh (ORCPT ); Thu, 7 Apr 2022 06:54:37 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A52F53055C for ; Thu, 7 Apr 2022 03:52:37 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6FE9212FC; Thu, 7 Apr 2022 03:52:37 -0700 (PDT) Received: from [192.168.178.6] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D26323F5A1; Thu, 7 Apr 2022 03:52:35 -0700 (PDT) Message-ID: <786190b3-b2cb-464d-9808-325d774c62a5@arm.com> Date: Thu, 7 Apr 2022 12:52:28 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [Linux 5.18-rc1] WARNING: CPU: 1 PID: 0 at kernel/sched/fair.c:3355 update_blocked_averages Content-Language: en-US To: Ammar Faizi , Linux Kernel Mailing List Cc: Ben Segall , Daniel Bristot de Oliveira , GNU/Weeb Mailing List , Ingo Molnar , Juri Lelli , Mel Gorman , Peter Zijlstra , Steven Rostedt , Vincent Guittot References: <675544de-3369-e26e-65ba-3b28fff5c126@gnuweeb.org> <000457c2-57af-95e3-7dff-2cbd99f0de5f@arm.com> <7f4b3fbf-c7c6-22cb-019b-520ad6a663aa@gnuweeb.org> From: Dietmar Eggemann In-Reply-To: <7f4b3fbf-c7c6-22cb-019b-520ad6a663aa@gnuweeb.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/04/2022 22:34, Ammar Faizi wrote: > On 4/6/22 7:21 PM, Dietmar Eggemann wrote: >> On 05/04/2022 15:13, Ammar Faizi wrote: >>> On 4/5/22 7:21 PM, Dietmar Eggemann wrote: [...] > Not familiar with CFS stuff, but here... > > =============== > ammarfaizi2@integral2:~$ mount | grep "cgroup2\|\bcpu\b" > cgroup2 on /sys/fs/cgroup type cgroup2 > (rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot) > ammarfaizi2@integral2:~$ cat /sys/fs/cgroup/unified/cgroup.controllers > cat: /sys/fs/cgroup/unified/cgroup.controllers: No such file or directory > ammarfaizi2@integral2:~$ ls /sys/fs/cgroup/{cpu,cpuacct} > ls: cannot access '/sys/fs/cgroup/cpu': No such file or directory > ls: cannot access '/sys/fs/cgroup/cpuacct': No such file or directory [...] Looks like 21.10 finally abandoned legacy cgroup v1 and switched to v2 completely, which is now mounted under /sys/fs/cgroup . So your /sys/fs/cgroup/cgroup.controllers should contain `cpu`. Can you check if any of the cpu.max files under /sys/fs/cgroup has something else then `max 100000` ? Background is that if this is the case, cgroups (i.e. cfs_rqs) might be throttled and this could be related to what you see. I haven't stress-test it so far with active CFS BW ctrl (cfs_rq throttling). > Update: > So far I have been using and torturing my machine for a day, but > still couldn't reproduce the issue. It seems I hit a rarely > happened bug. I will continue using this until 5.18-rc2 before > recompile my kernel. Thanks.