From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756363AbYGFJ0Z (ORCPT ); Sun, 6 Jul 2008 05:26:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752097AbYGFJZ4 (ORCPT ); Sun, 6 Jul 2008 05:25:56 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:56455 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752009AbYGFJZz (ORCPT ); Sun, 6 Jul 2008 05:25:55 -0400 Message-ID: <48708F23.2080702@cn.fujitsu.com> Date: Sun, 06 Jul 2008 17:23:47 +0800 From: Lai Jiangshan User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) MIME-Version: 1.0 To: "Paul E. McKenney" CC: Andrew Morton , torvalds@linux-foundation.org, Linux Kernel Mailing List Subject: Re: [RFC][PATCH] rcu classic: new algorithm for callbacks-processing References: <4844BE83.5010401@cn.fujitsu.com> <20080608151844.GA18751@linux.vnet.ibm.com> <485F17B2.5010700@cn.fujitsu.com> <20080623091349.GK22569@linux.vnet.ibm.com> In-Reply-To: <20080623091349.GK22569@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paul E. McKenney wrote: > > You tried this without your changes and it passed, correct? > > Never forget to test the base kernel. ;-) > Thanks, but I make some mistake here. I tested the base kernel, no bug occurred. So I try to find out bugs in my changes in 2 weeks. I added debug codes and these codes showed all processing are right and no callback broke its grace period but the bug still occurred. When I was puzzled after 2 weeks, I looked back the base kernel that I had tested, and I found that I forget to set CONFIG_NO_HZ=y. Then I set CONFIG_NO_HZ=y in the base kernel, and the bug occurred. It's exactly as the bug when my patch applied. I have reported this bug here: http://lkml.org/lkml/2008/7/3/24