Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754087Ab3FOFjR (ORCPT ); Sat, 15 Jun 2013 01:39:17 -0400 Received: from mail-pd0-f180.google.com ([209.85.192.180]:41501 "EHLO mail-pd0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752528Ab3FOFjP (ORCPT ); Sat, 15 Jun 2013 01:39:15 -0400 Date: Fri, 14 Jun 2013 22:39:12 -0700 From: Tejun Heo To: Michal Hocko Cc: lizefan@huawei.com, containers@lists.linux-foundation.org, cgroups@vger.kernel.org, koverstreet@google.com, linux-kernel@vger.kernel.org, cl@linux-foundation.org, Mike Snitzer , Vivek Goyal , "Alasdair G. Kergon" , Jens Axboe , Mikulas Patocka , Glauber Costa Subject: Re: [PATCH 11/11] cgroup: use percpu refcnt for cgroup_subsys_states Message-ID: <20130615053912.GB7017@htj.dyndns.org> References: <1371096298-24402-1-git-send-email-tj@kernel.org> <1371096298-24402-12-git-send-email-tj@kernel.org> <20130614132026.GD10084@dhcp22.suse.cz> <20130614223125.GD6593@mtj.dyndns.org> <20130615053522.GA7017@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130615053522.GA7017@htj.dyndns.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1473 Lines: 42 On Fri, Jun 14, 2013 at 10:35:22PM -0700, Tejun Heo wrote: > On Fri, Jun 14, 2013 at 03:31:25PM -0700, Tejun Heo wrote: > > I'll play with it a bit more on an actual machine and post more > > results. Test program attached. > > So, here are the results from the same test on a dual-socket 2-way > NUMA opteron 8 core machine. > > Running on one CPU. > > copy size atomic percpu diff in pct > 0 535964443 616756827 +15.07% > 32 399988186 378678713 -5.33% > 64 389067476 355073979 -8.74% > 128 342192631 315615300 -7.77% > 256 281208005 260598931 -7.33% > 512 188070912 193225269 +2.74% > > Running on all eight cores. > > copy size atomic percpu diff in pct > 0 121324328 4889425511 +3,930.05% > 32 96170193 2999613380 +3,019.07% > 64 98139061 2813894184 +2,767.25% > 128 112610025 2503229487 +2,122.92% > 256 96828114 2069865752 +2,037.67% > 512 95858297 1537726109 +1,504.17% A bit of addition, this of course is completely synthetic and exaggerates the differences both ways, but it's pretty clear that this is gonna be a clear gain in any kind of workload which would generate some amount of cross-CPU refcnting, which would be the norm anyway. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/