From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756200Ab3LDX2s (ORCPT ); Wed, 4 Dec 2013 18:28:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:4518 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752370Ab3LDX2r (ORCPT ); Wed, 4 Dec 2013 18:28:47 -0500 Date: Wed, 4 Dec 2013 18:28:38 -0500 From: Dave Jones To: paulmck@linux.vnet.ibm.com Cc: Linux Kernel Subject: lots of brief rcu stalls. Message-ID: <20131204232838.GA25592@redhat.com> Mail-Followup-To: Dave Jones , paulmck@linux.vnet.ibm.com, Linux Kernel MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paul, I'm seeing this happening more and more lately... [ 771.786462] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 771.786552] Tasks blocked on level-0 rcu_node (CPUs 0-3): [ 771.786574] Tasks blocked on level-0 rcu_node (CPUs 0-3): [ 771.786595] (detected by 0, t=6502 jiffies, g=20611, c=20610, q=0) [ 771.786620] INFO: Stall ended before state dump start [ 966.724546] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 966.724854] Tasks blocked on level-0 rcu_node (CPUs 0-3): [ 966.724931] Tasks blocked on level-0 rcu_node (CPUs 0-3): [ 966.725005] (detected by 0, t=26007 jiffies, g=20611, c=20610, q=0) [ 966.725093] INFO: Stall ended before state dump start [ 1161.661459] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 1161.661763] Tasks blocked on level-0 rcu_node (CPUs 0-3): [ 1161.661840] Tasks blocked on level-0 rcu_node (CPUs 0-3): [ 1161.661915] (detected by 0, t=45512 jiffies, g=20611, c=20610, q=0) [ 1161.662001] INFO: Stall ended before state dump start [ 1356.598205] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 1356.598513] Tasks blocked on level-0 rcu_node (CPUs 0-3): [ 1356.598590] Tasks blocked on level-0 rcu_node (CPUs 0-3): [ 1356.598664] (detected by 0, t=65017 jiffies, g=20611, c=20610, q=0) [ 1356.598751] INFO: Stall ended before state dump start [ 1551.536099] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 1551.536408] Tasks blocked on level-0 rcu_node (CPUs 0-3): [ 1551.536485] Tasks blocked on level-0 rcu_node (CPUs 0-3): [ 1551.536559] (detected by 0, t=84522 jiffies, g=20611, c=20610, q=0) [ 1551.536645] INFO: Stall ended before state dump start While it's apparently a non-problem, it's pretty noisy. Any ideas? Dave