From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755439Ab3GKAqr (ORCPT ); Wed, 10 Jul 2013 20:46:47 -0400 Received: from mga09.intel.com ([134.134.136.24]:65312 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754177Ab3GKAqq (ORCPT ); Wed, 10 Jul 2013 20:46:46 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,1040,1363158000"; d="scan'208";a="368145391" Message-ID: <51DE0073.3020403@intel.com> Date: Thu, 11 Jul 2013 08:46:43 +0800 From: "Yan, Zheng" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130514 Thunderbird/17.0.6 MIME-Version: 1.0 To: Peter Zijlstra CC: linux-kernel@vger.kernel.org, mingo@elte.hu, eranian@google.com, ak@linux.intel.com Subject: Re: [PATCH] perf: Update event buffer tail when overwriting old events References: <1370498286-12801-1-git-send-email-zheng.z.yan@intel.com> <20130708121557.GA17211@twins.programming.kicks-ass.net> <51DD4787.7080504@intel.com> <20130710114408.GS25631@dyad.programming.kicks-ass.net> In-Reply-To: <20130710114408.GS25631@dyad.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/10/2013 07:44 PM, Peter Zijlstra wrote: > On Wed, Jul 10, 2013 at 07:37:43PM +0800, Yan, Zheng wrote: >> On 07/08/2013 08:15 PM, Peter Zijlstra wrote: >>> On Thu, Jun 06, 2013 at 01:58:06PM +0800, Yan, Zheng wrote: >>>> From: "Yan, Zheng" > >>>> before overwrite mode after overwrite mode >>>> AVG 1000 999 1046 1044 >>>> STDEV 19.4 19.5 17.1 17.9 >>> >>> OK, so I was sure I replied to this email; but apparently I didn't :/ >>> >>> So its still adding about 5% overhead to the regular case; this is sad. >>> >>> What does something like the below do? >>> >> >> I re-test the patch on a different 32 core sandybridge-ep machine. the result is quite good. >> >> origin origin overwrite modified modified overwrite >> AVG 1000 1044 960 1006 >> STDEV 39.0 26.0 28.1 14.4 > > Nice! -- you did fix the snafu for the overwrite more before testing right? > yes, of course. Regards Yan, Zheng