From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751604Ab1GLOL1 (ORCPT ); Tue, 12 Jul 2011 10:11:27 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:35233 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751090Ab1GLOL0 (ORCPT ); Tue, 12 Jul 2011 10:11:26 -0400 Date: Tue, 12 Jul 2011 07:05:46 -0700 From: "Paul E. McKenney" To: Sander Eikelenboom Cc: Konrad Rzeszutek Wilk , julie Sullivan , xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org Subject: Re: [Xen-devel] Re: PROBLEM: 3.0-rc kernels unbootable since -rc3 Message-ID: <20110712140546.GC2326@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20110710171626.GK6014@linux.vnet.ibm.com> <20110710173530.GA16954@linux.vnet.ibm.com> <20110710214639.GP6014@linux.vnet.ibm.com> <20110710231449.GQ6014@linux.vnet.ibm.com> <20110711162450.GA22913@dumpdata.com> <20110711171337.GK2245@linux.vnet.ibm.com> <20110711193021.GA2996@dumpdata.com> <1981046693.20110712083317@eikelenboom.it> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1981046693.20110712083317@eikelenboom.it> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 12, 2011 at 08:33:17AM +0200, Sander Eikelenboom wrote: > Monday, July 11, 2011, 9:30:22 PM, you wrote: > > >> > >> Hmmm... Does the stall repeat about every 3.5 minutes after the first stall? > > > Starting Configure read-only root support... > > [ 81.335070] INFO: rcu_sched_state detected stalls on CPUs/tasks: { 0} (detected by 3, t=60002 jiffies) > > [ 81.335091] sending NMI to all CPUs: > > [ 261.367071] INFO: rcu_sched_state detected stalls on CPUs/tasks: { 0} (detected by 3, t=240034 jiffies) > > [ 261.367092] sending NMI to all CPUs: > > [ 441.399066] INFO: rcu_sched_state detected stalls on CPUs/tasks: { 0} (detected by 3, t=420066 jiffies) > > [ 441.399089] sending NMI to all CPUs: > > >> > >> One thing to try would be to disable CONFIG_RCU_FAST_NO_HZ. I wouldn't > >> expect this to have any effect, but might be worth a try. It is really > > > Did not help. > >> intended for small battery-powered systems. > >> > > Just as a note, i'm also seeing some stalls from domU's running a 3.0-rc kernel from you master tree (about 2 week old). > But it seems the first occurrences are not as quick after being booted. Unfortunately i haven't got time to investigate more this week. Should you get some time, providing the stack traces from the CPU stall warnings would give me something to go on. ;-) Thanx, Paul