From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756153AbaBFLyI (ORCPT ); Thu, 6 Feb 2014 06:54:08 -0500 Received: from mga14.intel.com ([143.182.124.37]:13940 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755766AbaBFLyG (ORCPT ); Thu, 6 Feb 2014 06:54:06 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.95,793,1384329600"; d="scan'208";a="470778086" Date: Thu, 6 Feb 2014 19:53:33 +0800 From: Fengguang Wu To: Peter Zijlstra Cc: "Paul E. McKenney" , LKML Subject: Re: [sched/preempt] INFO: rcu_sched self-detected stall on CPU { 1} Message-ID: <20140206115333.GA28544@localhost> References: <20140206095646.GE17971@localhost> <20140206112731.GH4941@twins.programming.kicks-ass.net> <20140206114635.GA27429@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140206114635.GA27429@localhost> 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 On Thu, Feb 06, 2014 at 07:46:35PM +0800, Fengguang Wu wrote: > On Thu, Feb 06, 2014 at 12:27:31PM +0100, Peter Zijlstra wrote: > > On Thu, Feb 06, 2014 at 05:56:46PM +0800, Fengguang Wu wrote: > > > Hi Peter, > > > > > > We noticed the below RCU stalls which will block the system. > > > The problem is bisected to > > > > > > commit 8cb75e0c4ec9786b81439761eac1d18d4a931af3 > > > Author: Peter Zijlstra > > > AuthorDate: Wed Nov 20 12:22:37 2013 +0100 > > > Commit: Ingo Molnar > > > CommitDate: Mon Jan 13 17:38:55 2014 +0100 > > > > > > sched/preempt: Fix up missed PREEMPT_NEED_RESCHED folding > > > > > > arch/x86/include/asm/mwait.h | 2 +- > > > include/linux/preempt.h | 15 +++++++++++++++ > > > include/linux/sched.h | 15 +++++++++++++++ > > > kernel/cpu/idle.c | 17 ++++++++++------- > > > kernel/sched/core.c | 3 +-- > > > 5 files changed, 42 insertions(+), 10 deletions(-) > > > > > > [ 85.786775] INFO: rcu_sched self-detected stall on CPU { 1} (t=15000 jiffies g=233 c=232 q=1940) > > > > Did the initial kernel contain the below? > > Nope, so I was testing some old tip sched/core.. Bisect log is Peter, I just checked and find no longer showing up in new kernel tests. So it must have been fixed up. Sorry for the noises! Regards, Fengguang