From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751913Ab1KCN2o (ORCPT ); Thu, 3 Nov 2011 09:28:44 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:41058 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751161Ab1KCN2n (ORCPT ); Thu, 3 Nov 2011 09:28:43 -0400 Date: Thu, 3 Nov 2011 06:25:50 -0700 From: "Paul E. McKenney" To: Josh Triplett Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, patches@linaro.org Subject: Re: [PATCH RFC tip/core/rcu 09/28] rcu: Document failing tick as cause of RCU CPU stall warning Message-ID: <20111103132550.GX2287@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20111102203017.GA3830@linux.vnet.ibm.com> <1320265849-5744-9-git-send-email-paulmck@linux.vnet.ibm.com> <20111103030750.GB2042@leaf> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111103030750.GB2042@leaf> User-Agent: Mutt/1.5.20 (2009-06-14) x-cbid: 11110313-1976-0000-0000-000000B20E36 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 02, 2011 at 08:07:50PM -0700, Josh Triplett wrote: > On Wed, Nov 02, 2011 at 01:30:30PM -0700, Paul E. McKenney wrote: > > One of lclaudio's systems was seeing RCU CPU stall warnings from idle. > > These turned out to be caused by a bug that stopped scheduling-clock > > tick interrupts from being sent to a given CPU for several hundred seconds. > > Out of curiosity, what caused this bug? If I remember correctly, software/configuration bugs in the clock code. Thanx, Paul