From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753846Ab2GBOUo (ORCPT ); Mon, 2 Jul 2012 10:20:44 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:61636 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750793Ab2GBOUn (ORCPT ); Mon, 2 Jul 2012 10:20:43 -0400 Subject: Re: [PATCHv3 0/3] perf tool: Add new event group management From: Namhyung Kim To: Jiri Olsa 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 In-Reply-To: <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> <20120702133341.GD967@krava.redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 02 Jul 2012 23:20:34 +0900 Message-ID: <1341238834.1476.50.camel@leonhard> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2012-07-02 (월), 15:33 +0200, Jiri Olsa: > 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. > What I said is just displaying cycles and faults events in above example on the same screen/table like: (Overhead) cycles faults Command Shared object Symbol ...... ...... ....... ................. .................. 92.98% 60.13% noploop noploop [.] main 3.21% 5.42% noploop [kernel.kallsyms] [k] __lock_acquire 1.16% 13.13% noploop libc-2.11.1.so [.] _int_malloc 0.97% 0.33% noploop [kernel.kallsyms] [k] clear_page_c ... We could pass such information to perf report explicitly, But I guess it 'd better if perf report did it for me automagically by detecting group relations. -- Regards, Namhyung Kim