Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932479AbZLPBVO (ORCPT ); Tue, 15 Dec 2009 20:21:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756120AbZLPBVN (ORCPT ); Tue, 15 Dec 2009 20:21:13 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:59579 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756092AbZLPBVE (ORCPT ); Tue, 15 Dec 2009 20:21:04 -0500 Message-ID: <4B283596.2010801@cn.fujitsu.com> Date: Wed, 16 Dec 2009 09:19:18 +0800 From: Xiao Guangrong User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: Frederic Weisbecker CC: Ingo Molnar , Thomas Gleixner , Peter Zijlstra , Steven Rostedt , LKML Subject: Re: [PATCH 0/4] perf_event: introduce 'perf timer' to analyze timer's behavior References: <4B27702F.1080507@cn.fujitsu.com> <20091215141533.GB5833@nowhere> In-Reply-To: <20091215141533.GB5833@nowhere> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1954 Lines: 45 Frederic Weisbecker wrote: > On Tue, Dec 15, 2009 at 07:17:03PM +0800, Xiao Guangrong wrote: >> Hi, >> >> We introduce 'perf timer' in this patchset, it can analyze timer >> latency and timer function handle time, the usage and result is >> like below: >> >> # perf timer record >> # perf timer lat --print-lat --print-handle >> ------------------------------------------------------------------------------------------------------- >> | Timer | TYPE | Avg-latency | Max-latency | Max-latency-at-TS |Max-lat-at-Task | >> |0xf7ad1f5c |hrtimer |996068.500 ns|1607650 ns|10270128658526 |init | >> |0xf7903f04 |timer |0.625 HZ|2 HZ|10270344082394 |swapper | >> |0xf787a05c |hrtimer |200239.500 ns|359929 ns|10269316024808 |main | >> |main :[ PROF]|itimer |0.000 HZ|0 HZ|10237021270557 |main | >> |main :[VIRTUAL]|itimer |0.000 HZ|0 HZ|10257314773501 |main | > > > > Cool! This is really a good work and a good idea. > > Just have some neats in mind. hrtimers and timers don't have the same latency and > granularity requirements. > > As you show it, timers have an HZ granularity and hrtimers are about nanoseconds, > and mixing them up in the same array of latency report is too messy. > They don't have the same granularity/latency scope so they should > be reported separately. > Yeah, it has different unit and looks ugly :-( but, the problem is we can't get HZ in userspace now, i'll export HZ by proc or other way and rectify 'perf timer' output in my next work Thanks, Xiao -- 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/