From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752131Ab2GTHAe (ORCPT ); Fri, 20 Jul 2012 03:00:34 -0400 Received: from charybdis-ext.suse.de ([195.135.221.2]:44450 "EHLO nat.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751173Ab2GTHAd (ORCPT ); Fri, 20 Jul 2012 03:00:33 -0400 Message-ID: <1342767624.7432.54.camel@marge.simpson.net> Subject: Re: [QUESTION ON BUG] the rcu stall issue could not be reproduced From: Mike Galbraith To: Michael Wang Cc: LKML , "paulmck@linux.vnet.ibm.com" , mmokrejs@fold.natur.cuni.cz, dan.carpenter@oracle.com Date: Fri, 20 Jul 2012 09:00:24 +0200 In-Reply-To: <5008CBD4.6070907@linux.vnet.ibm.com> References: <5008CBD4.6070907@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2012-07-20 at 11:09 +0800, Michael Wang wrote: > Hi, Mike, Martin, Dan > > I'm currently taking an eye on the rcu stall issue which was reported by > you in the mail: > > rcu: endless stalls > From: Mike Galbraith > linux-3.4-rc7: rcu_sched self-detected stall on CPU > From: Martin Mokrejs > RCU stalls in linux-next > From: Dan Carpenter > > I try to reproduce the issue on my X86 server with 12 cpu The 'endless stalls' box was 341.33333 times larger. Dunno if you can even set a serial port slow enough to approximate all cores trying to gripe through a single pinhole simultaneously. -Mike