From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752124Ab2CPEpe (ORCPT ); Fri, 16 Mar 2012 00:45:34 -0400 Received: from mailout-de.gmx.net ([213.165.64.22]:37424 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750908Ab2CPEpd (ORCPT ); Fri, 16 Mar 2012 00:45:33 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX18XSaJWHNcXNY44rsexRADIIOcHr4QZup0vlZeD7+ 7ejZLBDILdp9UE Message-ID: <1331873113.7399.19.camel@marge.simpson.net> Subject: Re: [PATCH RFC] rcu: Limit GP initialization to CPUs that have been online From: Mike Galbraith To: paulmck@linux.vnet.ibm.com Cc: Dimitri Sivanich , linux-kernel@vger.kernel.org Date: Fri, 16 Mar 2012 05:45:13 +0100 In-Reply-To: <20120315170236.GF2381@linux.vnet.ibm.com> References: <20120314002414.GA21561@linux.vnet.ibm.com> <1331717099.5752.15.camel@marge.simpson.net> <1331728841.7465.7.camel@marge.simpson.net> <20120314130801.GA11722@sgi.com> <20120314151717.GA2435@linux.vnet.ibm.com> <20120314165657.GA19117@linux.vnet.ibm.com> <1331779343.14263.6.camel@marge.simpson.net> <1331780831.14263.15.camel@marge.simpson.net> <20120315170236.GF2381@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.1 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2012-03-15 at 10:02 -0700, Paul E. McKenney wrote: > On Thu, Mar 15, 2012 at 04:07:11AM +0100, Mike Galbraith wrote: > > On Thu, 2012-03-15 at 03:42 +0100, Mike Galbraith wrote: > > > On Wed, 2012-03-14 at 09:56 -0700, Paul E. McKenney wrote: > > > > > > > Does the following work better? It does pass my fake-big-system tests > > > > (more testing in the works). > > > > > > Yup, tip booted fine. Thanks! I'll test, see if it gets upset. > > > > Wedged into 3.0 enterprise booted fine too, is now running rcutorture. > > I'll add hotplug after it runs explosion free for a while. Any > > suggestions for giving both virgin and 3.0 a thorough trouncing? > > It would be good to check the latency of RCU's grace-period > initialization, and comparing the results with and without this patch. > Dimitri might have scripting for that. Yeah, I'll zoom in. Generic irqsoff tracing with rcutorture running was... not the cleverest of ideas. (between fbcon and serial console, a 300us RCU blip would be a pimple on giants left butt cheek) -Mike