From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753474Ab3CFQOv (ORCPT ); Wed, 6 Mar 2013 11:14:51 -0500 Received: from mail1.windriver.com ([147.11.146.13]:57054 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753074Ab3CFQOs (ORCPT ); Wed, 6 Mar 2013 11:14:48 -0500 Message-ID: <51376B5D.7040108@windriver.com> Date: Wed, 6 Mar 2013 11:14:21 -0500 From: Paul Gortmaker User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Thomas Gleixner CC: "Paul E. McKenney" , , Subject: Re: Threaded irqs + 100% CPU RT task = RCU stall References: <20130306154917.GA15249@windriver.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [128.224.146.65] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13-03-06 10:58 AM, Thomas Gleixner wrote: > On Wed, 6 Mar 2013, Paul Gortmaker wrote: >> So, I guess the question is, whether we want to try and make the system >> fail in a more meaningful way -- kind of like the rt throttling message >> does - as it lets users know they've hit the wall? Something watching > > That Joe Doe should have noticed the throttler message, which came > before the stall, shouldn't he? Actually it isn't showing up at all -- just the RCU stall itself. Now that you mention it, I do wonder why the throttler message isn't tripped though... Paul. -- > >> for kstat_incr_softirqs traffic perhaps? Or other options? > > The rcu stall detector could use the softirq counter and if it did not > change in the stall period print: "Caused by softirq starvation" or > something like that. > > Thanks, > > tglx > >