From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932101Ab2BAOcO (ORCPT ); Wed, 1 Feb 2012 09:32:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59239 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753820Ab2BAOcN (ORCPT ); Wed, 1 Feb 2012 09:32:13 -0500 Date: Wed, 1 Feb 2012 15:31:37 +0100 From: Jiri Olsa To: Peter Zijlstra Cc: Corey Ashford , acme@redhat.com, mingo@elte.hu, paulus@samba.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/9] perf: Adding sysfs group format attribute for pmu device Message-ID: <20120201143137.GD1655@m.brq.redhat.com> References: <1326717103-10287-1-git-send-email-jolsa@redhat.com> <1327674868-10486-1-git-send-email-jolsa@redhat.com> <1327674868-10486-6-git-send-email-jolsa@redhat.com> <4F231256.8080905@linux.vnet.ibm.com> <20120130095223.GB1552@m.brq.redhat.com> <4F289486.2050107@linux.vnet.ibm.com> <20120201131340.GC1655@m.brq.redhat.com> <1328105932.2662.5.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1328105932.2662.5.camel@laptop> 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 Wed, Feb 01, 2012 at 03:18:52PM +0100, Peter Zijlstra wrote: > On Wed, 2012-02-01 at 14:13 +0100, Jiri Olsa wrote: > > > Are you are suggesting that a single event could use multiple groups > > > because they may share some common fields, such as the event code? If > > > so, I think that might be confusing. I think it would be better to > > > have every group fully lay out the bits in the config{,1,2} fields so > > > that you only need to specify one group per event, even if that leads to > > > some redundancy (e.g. group1..n all have an eventcode field.) > > > > ok, it'd be the 'cpu::group1/config=1,config1=2,config2=3/u' then.. > > > > but let's see what Peter thinks about this, since he first suggested > > to 'fix' this by having separate pmu drivers.. not format groups :) > > I'm not convinced we need the whole grouping thing. Even x86 might have > overlapping definitions, even for a single PMU (config1 contents will > radically differ depending on the actual events used for instance). well, I think let's go with what we have now, and see if need/want to care about format groups later after we use it for a while.. since the "cpu/..../" syntax is new interface, there should be no problem to change it > > All we should do is warn the user when overlapping masks are used in a > single event definition and other than that just do as they tell us. that should be no problem.. do you want it in to take this.. ooor is later ok ;) jirka > > PMUs can always do an informal namespace thing if really needed, eg. by > using a consistent prefix. >