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=-7.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 E7569C64E7B for ; Wed, 2 Dec 2020 22:02:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8017C221EB for ; Wed, 2 Dec 2020 22:02:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726670AbgLBWBn (ORCPT ); Wed, 2 Dec 2020 17:01:43 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:45822 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725933AbgLBWBn (ORCPT ); Wed, 2 Dec 2020 17:01:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606946416; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xUGe+rDHdo1Ey22JIXtc3/BYf9lsKUsUkDP2aASmHF4=; b=gxMj7MB0MCOOQjRy+MH2lL97GpQlAyn+tdpeMOY8LvFsz2Qz2hLWgUM6FpMJosBPiUwpjn 267DfB3HoNFk/vFN4ckA/NSvinf5gR7OMWFq39ipPMB4LiQPFA2EgbypJtXi6W5XVGT9LC u6ZEXyAyLPtJXb4JMzFwimtlH+/FJY0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-223-dhN_EC5PM8C2n4Yjfs1Cnw-1; Wed, 02 Dec 2020 17:00:14 -0500 X-MC-Unique: dhN_EC5PM8C2n4Yjfs1Cnw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BBB71100F341; Wed, 2 Dec 2020 22:00:11 +0000 (UTC) Received: from ovpn-66-132.rdu2.redhat.com (unknown [10.10.67.132]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3899A60BFA; Wed, 2 Dec 2020 21:59:56 +0000 (UTC) Message-ID: Subject: Re: [PATCH v4 11/19] sched/core: Make migrate disable and CPU hotplug cooperative From: Qian Cai To: Sebastian Andrzej Siewior Cc: Valentin Schneider , Peter Zijlstra , tglx@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org, qais.yousef@arm.com, swood@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vincent.donnefort@arm.com, tj@kernel.org, ouwen210@hotmail.com Date: Wed, 02 Dec 2020 16:59:56 -0500 In-Reply-To: <20201123181313.ug4fwjcqnmbvo3f2@linutronix.de> References: <20201023101158.088940906@infradead.org> <20201023102347.067278757@infradead.org> <20201123181313.ug4fwjcqnmbvo3f2@linutronix.de> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2020-11-23 at 19:13 +0100, Sebastian Andrzej Siewior wrote: > On 2020-11-18 09:44:34 [-0500], Qian Cai wrote: > > On Tue, 2020-11-17 at 19:28 +0000, Valentin Schneider wrote: > > > We did have some breakage in that area, but all the holes I was aware of > > > have been plugged. What would help here is to see which tasks are still > > > queued on that outgoing CPU, and their recent activity. > > > > > > Something like > > > - ftrace_dump_on_oops on your kernel cmdline > > > - trace-cmd start -e 'sched:*' > > > > > > > > > ought to do it. Then you can paste the (tail of the) ftrace dump. > > > > > > I also had this laying around, which may or may not be of some help: > > > > Once I have found a reliable reproducer, I'll report back. > > any update? Just back from a vacation. I have been running the same workload on today's linux-next for a few hours and it has been good so far. I'll surely report back if it happens again in our daily runs.