From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932164Ab3CFP7D (ORCPT ); Wed, 6 Mar 2013 10:59:03 -0500 Received: from www.linutronix.de ([62.245.132.108]:43970 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753334Ab3CFP7B (ORCPT ); Wed, 6 Mar 2013 10:59:01 -0500 Date: Wed, 6 Mar 2013 16:58:54 +0100 (CET) From: Thomas Gleixner To: Paul Gortmaker cc: "Paul E. McKenney" , linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Threaded irqs + 100% CPU RT task = RCU stall In-Reply-To: <20130306154917.GA15249@windriver.com> Message-ID: References: <20130306154917.GA15249@windriver.com> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? > 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