Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753826Ab1DNBET (ORCPT ); Wed, 13 Apr 2011 21:04:19 -0400 Received: from mga02.intel.com ([134.134.136.20]:65044 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752364Ab1DNBER (ORCPT ); Wed, 13 Apr 2011 21:04:17 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.64,208,1301900400"; d="scan'208";a="628259756" Subject: Re: [patch v2 0/4] percpu_counter: cleanup and fix From: Shaohua Li To: Christoph Lameter Cc: "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "tj@kernel.org" , "eric.dumazet@gmail.com" In-Reply-To: References: <20110413075715.090406229@sli10-conroe.sh.intel.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 14 Apr 2011 09:04:13 +0800 Message-ID: <1302743053.3981.178.camel@sli10-conroe> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1147 Lines: 26 On Wed, 2011-04-13 at 22:08 +0800, Christoph Lameter wrote: > On Wed, 13 Apr 2011, shaohua.li@intel.com wrote: > > > Cleanup percpu_counter code and fix some bugs. The main purpose is to convert > > percpu_counter to use atomic64, which is useful for workloads which cause > > percpu_counter->lock contented. In a workload I tested, the atomic method is > > 50x faster (please see patch 4 for detail). > > Could you post your test and the results please? the test is very simple, 24 processes in 24 CPU, and each does: while (1) { mmap(128M); munmap(128M) } we then measure how many loops the process can do. I'll attach the test in next post. Just found when I said 50x faster, I actually forgot one other patch's effect, which is http://marc.info/?l=linux-kernel&m=130127782901127&w=2. If only having the atomic change, it's about 7x faster. Sorry about this. I'll add detail data in next post. -- 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/