From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752802AbcHJWns (ORCPT ); Wed, 10 Aug 2016 18:43:48 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54403 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752342AbcHJWnq (ORCPT ); Wed, 10 Aug 2016 18:43:46 -0400 Date: Wed, 10 Aug 2016 15:43:45 -0700 From: Andrew Morton To: robert.foss@collabora.com Cc: adurbin@chromium.org, penguin-kernel@I-love.SAKURA.ne.jp, linux-kernel@vger.kernel.org Subject: Re: [PACTH v1] kernel/hung_task.c: Dump all UNINTERUPTIBLE tasks Message-Id: <20160810154345.f0c34d0936b0835b541405b0@linux-foundation.org> In-Reply-To: <1470151391-16420-1-git-send-email-robert.foss@collabora.com> References: <1470151391-16420-1-git-send-email-robert.foss@collabora.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2 Aug 2016 11:23:11 -0400 robert.foss@collabora.com wrote: > From: Aaron Durbin > > When the panic path is taken for khungtaskd dump all > tasks with the UNINTERUPTIBLE state. That way, any > inter-dependent tasks that caused one another to hang > will be saved in the crash output. > > ... > > --- a/kernel/hung_task.c > +++ b/kernel/hung_task.c > @@ -122,6 +122,8 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout) > touch_nmi_watchdog(); > > if (sysctl_hung_task_panic) { > + /* Dump all tasks. */ > + show_state_filter(TASK_UNINTERRUPTIBLE); > trigger_all_cpu_backtrace(); > panic("hung_task: blocked tasks"); > } Well, it's going to produce more gunk for the operator to read through and understand. I'd like to hear a little more about the value of this change: what particular problem prompted it, etc.