From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754152Ab2GFBGo (ORCPT ); Thu, 5 Jul 2012 21:06:44 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:38082 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752157Ab2GFBGm (ORCPT ); Thu, 5 Jul 2012 21:06:42 -0400 MIME-Version: 1.0 In-Reply-To: <20120705164447.GE7533@infradead.org> 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> <20120705164447.GE7533@infradead.org> Date: Fri, 6 Jul 2012 03:06:41 +0200 Message-ID: Subject: Re: [PATCHv3 0/3] perf tool: Add new event group management From: Stephane Eranian To: Arnaldo Carvalho de Melo Cc: Jiri Olsa , Namhyung Kim , 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 Content-Type: text/plain; charset=UTF-8 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 5, 2012 at 6:44 PM, Arnaldo Carvalho de Melo wrote: > Em Thu, Jul 05, 2012 at 06:15:20PM +0200, Stephane Eranian escreveu: >> On Mon, Jul 2, 2012 at 3:33 PM, Jiri Olsa wrote: >> > 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' >> > >> I don't understand why you actually need the :2 suffix. There can >> only be one leader. So assume it is the first one. Users have to >> know the first one is the leader which seems like a natural thing >> to do for me. It would make you syntax less ugly than it already >> is. > > Agreed, looks like creeping featurism. > >> I would have thought you could enable this with a simple >> cmdline option which changes the way you interpret the >> multiple -e options: >> >> perf record --group-reads -e e1,e2,e3 -e e4,e5,e6 ..... >> >> Would setup the group leaders (e1, e4) for 2 groups. >> NO curly braces, no : needed. > > Yeah, curly braces needed just when one wants to add group wide > modifiers. And even, in that case that seems overkill too. You can simply repeat the modifier on each event. A group cannot big that big. It is limited in size by the number of physical counters plus the events constraints.