From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755568Ab1E1EEB (ORCPT ); Sat, 28 May 2011 00:04:01 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:25084 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754454Ab1E1EEA (ORCPT ); Sat, 28 May 2011 00:04:00 -0400 Message-ID: <4DE07413.5050408@kernel.org> Date: Fri, 27 May 2011 21:03:31 -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: <4DDC21E1.1070502@kernel.org> <4DDC48E3.1060108@kernel.org> <20110525045253.GB2262@linux.vnet.ibm.com> <4DDD7F96.3090408@kernel.org> <20110525223437.GO2341@linux.vnet.ibm.com> <4DDD8775.1000501@kernel.org> <20110526011310.GP2341@linux.vnet.ibm.com> <20110526013029.GA28103@linux.vnet.ibm.com> <20110526162802.GC2386@linux.vnet.ibm.com> <20110528010448.GA21955@linux.vnet.ibm.com> In-Reply-To: <20110528010448.GA21955@linux.vnet.ibm.com> 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=0001.0A090204.4DE0741D.0034,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/27/2011 06:04 PM, Paul E. McKenney wrote: > > And, after having repeatedly shot myself in the foot trying to make > an all-singing all-dancing RCU grace-period latency measurement tool, > I fell back to simply measuring the RCU grace-period latency during > the time that memory_dev_init() is running. This assumes that the > grace periods are started using synchronize_rcu() -- if they are instead > being started using call_rcu(), I can adapt to that as well. > [ 31.635137] cpu_dev_init done [ 31.635320] Starting RCU latency diagnostics [ 71.605662] Ending RCU latency diagnostics [ 71.605924] memory_dev_init done Thanks Yinghai