From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932779AbdJaUXw (ORCPT ); Tue, 31 Oct 2017 16:23:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:21730 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932356AbdJaUXv (ORCPT ); Tue, 31 Oct 2017 16:23:51 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 390617EAA5 Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=dzickus@redhat.com Date: Tue, 31 Oct 2017 16:23:50 -0400 From: Don Zickus To: Guenter Roeck Cc: Peter Zijlstra , Thomas Gleixner , linux-kernel@vger.kernel.org, Ingo Molnar Subject: Re: Crashes in perf_event_ctx_lock_nested Message-ID: <20171031202350.lvmoyup56rlkmjqq@redhat.com> References: <20171030224512.GA13592@roeck-us.net> <20171031134850.ynix2zqypmca2mtt@hirez.programming.kicks-ass.net> <20171031171622.GA28688@roeck-us.net> <20171031185059.2yl4qrxvrqqzra3d@redhat.com> <20171031201208.GA23413@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171031201208.GA23413@roeck-us.net> User-Agent: NeoMutt/20171013 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Tue, 31 Oct 2017 20:23:51 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > Is Chrome OS, changing the default timeout from 10s to something else? > > That would explain it as a script is executed late in the boot cycle and > > explain the quick restart. > > > > Correct, Chrome OS changes the timeout from 10 to 5 seconds. > > A little experiment suggests that the problem can be triggered by updating > /proc/sys/kernel/watchdog_thresh. hardlockup_detector_perf_enable() is > called while hardlockup_detector_perf_cleanup() is running. Ok, that makes sense then. Though I thought I tested that before acking it. I will try to duplicate that on my end and see if various solutions could work. Cheers, Don