From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752355AbbCGSra (ORCPT ); Sat, 7 Mar 2015 13:47:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45400 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751261AbbCGSr2 (ORCPT ); Sat, 7 Mar 2015 13:47:28 -0500 Date: Sat, 7 Mar 2015 18:59:54 +0000 From: Alexander Gordeev To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/9] rcu: Cleanup rcu_init_geometry() code and arithmetics Message-ID: <20150307185954.GB15033@agordeev.usersys.redhat.com> References: <20150307180821.GN5236@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150307180821.GN5236@linux.vnet.ibm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Mar 07, 2015 at 10:08:21AM -0800, Paul E. McKenney wrote: > The rest of this series looks promising, but I do have to ask... How have > you tested these? The most straightforward approach would be to find I tried trees with 1,2 and 3 levels on a 160-CPU machine + dozens of kernel builds with 'make -j160'. I feel bit guilty I did not try the corner case with 4 levels, but run-time-wise it is not really differ from what I done. Do you expect the below is a better option? > a KVM-capable system with at least 16 CPUs and type the following from > the top-level directory: > > sh tools/testing/selftests/rcutorture/bin/kvm.sh --cpus 34 --duration 5 > > This will do a series of 16 build-boot-test cycles with various configs > (including various rcu_node tree shapes), and print a summary of the > outcome at the end. > > For these sorts of changes, I usually also do some user-level testing. -- Regards, Alexander Gordeev agordeev@redhat.com