Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755044Ab1DWDzt (ORCPT ); Fri, 22 Apr 2011 23:55:49 -0400 Received: from oproxy1-pub.bluehost.com ([66.147.249.253]:34646 "HELO oproxy1-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754317Ab1DWDzs (ORCPT ); Fri, 22 Apr 2011 23:55:48 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=xenotime.net; h=Received:Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References:Organization:X-Mailer:Mime-Version:Content-Type:Content-Transfer-Encoding:X-Identified-User; b=U8uS9PN1wE8uA1BlXoZPEg326xHtlHNxPmC13+F/oaq5VDzuXdlnTEd4kgkU5KJRoespaHKRt+ztn95vtNaun8I4eHADVeWj3mbkZGyDw3wU0z0AVyL/3Nrc6RMVjS9B; Date: Fri, 22 Apr 2011 20:55:45 -0700 From: Randy Dunlap To: Ben Greear Cc: Linux Kernel Mailing List Subject: Re: Debugging hung tasks? Message-Id: <20110422205545.19196ada.rdunlap@xenotime.net> In-Reply-To: <4DB20AA9.4080801@candelatech.com> References: <4DB20AA9.4080801@candelatech.com> Organization: YPO4 X-Mailer: Sylpheed 2.7.1 (GTK+ 2.16.6; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Identified-User: {1807:box742.bluehost.com:xenotime:xenotime.net} {sentby:smtp auth 50.53.38.135 authed with rdunlap@xenotime.net} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1070 Lines: 31 On Fri, 22 Apr 2011 16:09:29 -0700 Ben Greear wrote: > I am testing lots of NFS traffic against an over-loaded and slow file server. > > I enabled the hung-task detection logic, and it's hitting after 180 > seconds. > > First: Is there any valid reason to have funky NFS cause a hung task? > > Second: Why doesn't the hung-task panic logic print the stack trace of > the hung task? > Is this an option that can be enabled? hung_task.c::check_hung_task() always calls sched_show_task() and optionally does the panic: if (sysctl_hung_task_panic) panic("hung_task: blocked tasks"); sched.c::sched_show_task() calls show_stack(), which should be doing what you are asking for AFAICT. What kernel version are you using? --- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code *** -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/