From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751510AbeAEMxs (ORCPT + 1 other); Fri, 5 Jan 2018 07:53:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:43590 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751230AbeAEMxq (ORCPT ); Fri, 5 Jan 2018 07:53:46 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F2E54218D8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=acme@kernel.org Date: Fri, 5 Jan 2018 09:53:41 -0300 From: Arnaldo Carvalho de Melo To: "Jin, Yao" Cc: jolsa@kernel.org, peterz@infradead.org, mingo@redhat.com, alexander.shishkin@linux.intel.com, Linux-kernel@vger.kernel.org, ak@linux.intel.com, kan.liang@intel.com, yao.jin@intel.com Subject: Re: [PATCH v7 2/6] perf record: Get the first sample time and last sample time Message-ID: <20180105125341.GA25476@kernel.org> References: <1512738826-2628-1-git-send-email-yao.jin@linux.intel.com> <1512738826-2628-3-git-send-email-yao.jin@linux.intel.com> <20180104190903.GB20593@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Em Fri, Jan 05, 2018 at 09:15:03AM +0800, Jin, Yao escreveu: > > > On 1/5/2018 3:09 AM, Arnaldo Carvalho de Melo wrote: > > Em Fri, Dec 08, 2017 at 09:13:42PM +0800, Jin Yao escreveu: > > > In the default 'perf record' configuration, all samples are processed, > > > to create the HEADER_BUILD_ID table. So it's very easy to get the > > > first/last samples and save the time to perf file header via the > > > function write_sample_time(). > > > > > > Later, at post processing time, perf report/script will fetch > > > the time from perf file header. > > > > So, at this point I was expecting that that record would be present on > > the perf.data file: > > > > [acme@jouet perf]$ perf record --timestamp-boundary sleep 1 > > Cannot read kernel map > > [ perf record: Woken up 1 times to write data ] > > [ perf record: Captured and wrote 0.001 MB perf.data (7 samples) ] > > [acme@jouet perf]$ perf report -D | grep PERF_RECORD_SAMPLE | wc -l > > 7 > > [acme@jouet perf]$ perf report -D | grep PERF_RECORD_SAMPLE_TIME > > [acme@jouet perf]$ > > > > What am I doing wrong? > > > > To clarify, this is with just the first two patches in this series > > applied. > > > > - Arnaldo > > Hi Arnaldo, > > The timestamp boundary information is saved in perf file header. Right, my bad, I somehow thought it would be as PERF_RECORD_SAMPLE_TIME, duh. Will continue reviewing, sorry about that. - Arnaldo > So if we want to look at them, we need to add '--header' in perf report. > > For example, > > root@skl:/tmp# perf report -D --header | grep 'time of' > # time of first sample : 248333.706656 > # time of last sample : 248357.215328 > > Thanks > Jin Yao