From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753538Ab2GBNeZ (ORCPT ); Mon, 2 Jul 2012 09:34:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:61994 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753116Ab2GBNeY (ORCPT ); Mon, 2 Jul 2012 09:34:24 -0400 Date: Mon, 2 Jul 2012 15:33:41 +0200 From: Jiri Olsa To: Namhyung Kim Cc: acme@redhat.com, a.p.zijlstra@chello.nl, mingo@elte.hu, paulus@samba.org, cjashfor@linux.vnet.ibm.com, fweisbec@gmail.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, andi@firstfloor.org, drepper@gmail.com, eranian@google.com Subject: Re: [PATCHv3 0/3] perf tool: Add new event group management Message-ID: <20120702133341.GD967@krava.redhat.com> References: <1340960907-3725-1-git-send-email-jolsa@redhat.com> <87fw9blyhj.fsf@sejong.aot.lge.com> <20120702101518.GC967@krava.redhat.com> <1341234662.1476.13.camel@leonhard> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1341234662.1476.13.camel@leonhard> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 02, 2012 at 10:11:02PM +0900, Namhyung Kim wrote: > 2012-07-02 (월), 12:15 +0200, Jiri Olsa: > > On Mon, Jul 02, 2012 at 10:53:44AM +0900, Namhyung Kim wrote: > > > Just a question, is there a way to know about the grouping at perf > > > report time? > > > > nope, AFAIK only ID and perf_event_attr is stored for event > > grouping is known only for record time > > > > I heard that Arnaldo (or Stephane) wanted to make perf report > group-aware or such so that it can show related events together. But to > do that, it seems we need to change the data file format first, right? > > Any idea? The next change I'm working on is to record and report PERF_FORMAT_GROUP related data. Here's commit comment from my next patchset: --- perf, tool: Enable sampling on specified event group leader Adding the functionality to the group modifier event syntax. Allowing user to select leader event inside the group using event index (command line event position in the group). Following example selects e2 as leader: -e '{e1,e2,e3,e4}:2' The selected event becomes group leader and is the only one doing samples. The rest of the events in the group are being read on each leader event sample by PERF_SAMPLE_READ sample type processing. Following example: perf record -e {cycles,faults}:1 ls - creates a group with 'cycles' and 'faults' events - 'cycles' event is group leader and has sampling enabled - 'faults' event is read each time 'cycles' sample, the 'faults' count is attached to the 'cycles sample via PERF_SAMPLE_READ sample type. --- The report does not need any new metadata about grouping, because the samples are generated/stored only from the group leader. The other events data are read from the PERF_FORMAT_GROUP leader sample data. So no data file format change for my next changes, but I'm not sure this is the report change you mean. jirka