From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757852Ab1EWW43 (ORCPT ); Mon, 23 May 2011 18:56:29 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:38262 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755210Ab1EWW42 (ORCPT ); Mon, 23 May 2011 18:56:28 -0400 Message-ID: <4DDAE5FA.2030303@kernel.org> Date: Mon, 23 May 2011 15:55:54 -0700 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110414 SUSE/3.1.10 Thunderbird/3.1.10 MIME-Version: 1.0 To: paulmck@linux.vnet.ibm.com CC: linux-kernel@vger.kernel.org, mingo@redhat.com, hpa@zytor.com, tglx@linutronix.de, mingo@elte.hu Subject: Re: [tip:core/rcu] Revert "rcu: Decrease memory-barrier usage based on semi-formal proof" References: <4DD6D746.6070107@kernel.org> <20110520224250.GL2366@linux.vnet.ibm.com> <4DD6F4A2.1070401@kernel.org> <20110520231428.GN2366@linux.vnet.ibm.com> <4DD6F64C.3030402@kernel.org> <20110520234923.GQ2366@linux.vnet.ibm.com> <4DD70120.9090801@kernel.org> <20110521131844.GE2271@linux.vnet.ibm.com> <20110521140845.GA12157@linux.vnet.ibm.com> <4DDAC01E.7050602@kernel.org> <20110523212530.GF7428@linux.vnet.ibm.com> <4DDAD934.9010603@kernel.org> In-Reply-To: <4DDAD934.9010603@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: rtcsinet21.oracle.com [66.248.204.29] X-CT-RefId: str=0001.0A090209.4DDAE601.0036,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/23/2011 03:01 PM, Yinghai Lu wrote: > On 05/23/2011 02:25 PM, Paul E. McKenney wrote: >> On Mon, May 23, 2011 at 01:14:22PM -0700, Yinghai Lu wrote: >>> On 05/21/2011 07:08 AM, Paul E. McKenney wrote: >>>> On Sat, May 21, 2011 at 06:18:44AM -0700, Paul E. McKenney wrote: >>>>> On Fri, May 20, 2011 at 05:02:40PM -0700, Yinghai Lu wrote: >>>>>> On 05/20/2011 04:49 PM, Paul E. McKenney wrote: >>>>>>> On Fri, May 20, 2011 at 04:16:28PM -0700, Yinghai Lu wrote: >>>>>> ... >>>>>>>> >>>>>>>> the same one i sent out before, but let DEBUG_LOCKING_API_SELFTESTS disabled. >>>>>>> >>>>>>> OK, just to make sure I understand... You are compiling exactly the >>>>>>> same kernel source tree with exactly the same .config, just with two >>>>>>> different versions of gcc, correct? >>>>>> yes. >>>>>>> >>>>>>> If so, it is quite possible that the slow one is the correct one. :-/ >>>>>> yeah, new version always have problem. >>>>>> >>>>>> looks like opensuse11.3 has 4.5.0 and fedora14 has 4.5.1 >>>>> >>>>> OK, so fedora14 is the fast one (4.5.1) and opensuse11.3 is the slow >>>>> one (4.5.0), correct? >>>> >>>> And does commit c7a3786030 help? This commit (from Peter Zijlstra) >>>> tidied up RCU kthreads' scheduler interactions. The patch is below, >>>> though it is probably more convenient to pull it from the rcu/next >>>> branch of: >>>> >>>> git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu.git >>>> >> gcc in Fedora 14 is fine with your tree. Looks like I need to dump openuse 11.3 now. Thanks Yinghai