Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759074AbZLPHmp (ORCPT ); Wed, 16 Dec 2009 02:42:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752052AbZLPHmn (ORCPT ); Wed, 16 Dec 2009 02:42:43 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:61520 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752822AbZLPHmm (ORCPT ); Wed, 16 Dec 2009 02:42:42 -0500 Message-ID: <4B288F04.5080108@cn.fujitsu.com> Date: Wed, 16 Dec 2009 15:40:52 +0800 From: Xiao Guangrong User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: Ingo Molnar CC: Paul Mackerras , Frederic Weisbecker , 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> <4B283596.2010801@cn.fujitsu.com> <20091216073248.GA32713@elte.hu> In-Reply-To: <20091216073248.GA32713@elte.hu> 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: 1296 Lines: 39 Ingo Molnar wrote: >>> >> 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 > > We could export HZ as part of the ftrace event format file, in > /debug/tracing/events/timers/ or so. Not sure what the best way would be to do > it (without causing runtime overhead in event processing), but we should > reduce our reliance on /proc and export such instrumentation information via a > single, coherent interface. > Hi ingo, Um, if we export this value in tracepoint format, it should add for every timer's tracepoint. > There's a couple of other 'system settings' values that would be useful to > expose in such a way - for example the number of online CPUs. (in fact that > could be exposed as a set of online/offline events plus a way to read the > current count as well) > How about export those values in debugfs/tracing/*? perf tracepoint self depend on this filesystem. 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/