From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757649Ab3EJP3S (ORCPT ); Fri, 10 May 2013 11:29:18 -0400 Received: from merlin.infradead.org ([205.233.59.134]:42863 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757499Ab3EJP3R (ORCPT ); Fri, 10 May 2013 11:29:17 -0400 Date: Fri, 10 May 2013 17:27:38 +0200 From: Peter Zijlstra To: Michael Ellerman Cc: acme@infradead.org, jolsa@redhat.com, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, rob@landley.net Subject: Re: [RFC/PATCH] perf: Expand definition of sysfs format attribute Message-ID: <20130510152738.GA885@dyad.programming.kicks-ass.net> References: <1362370865-4437-1-git-send-email-michael@ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1362370865-4437-1-git-send-email-michael@ellerman.id.au> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 04, 2013 at 03:21:05PM +1100, Michael Ellerman wrote: > Make it explicit that the format attributes may define overlapping bit > ranges. Unfortunately this was left unspecified originally, and all the > examples show non-overlapping ranges. I don't believe this is an ABI > change, as we are defining something that was previously undefined, but > others may disagree. > > The POWER8 PMU would like to define overlapping ranges, as bit ranges in > the event code have different meanings for certain events. It will also > allow us to define an overarching "event" field, that encompasses all > others. > > As far as I can see perf is comfortable with this change, however I am > not sure if there are any other users of the interface. > > Signed-off-by: Michael Ellerman Jiri was going to collect to send to Ingo.. Acked-by: Peter Zijlstra > --- > Documentation/ABI/testing/sysfs-bus-event_source-devices-format | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-format b/Documentation/ABI/testing/sysfs-bus-event_source-devices-format > index 079afc7..77f47ff 100644 > --- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-format > +++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-format > @@ -9,6 +9,12 @@ Description: > we want to export, so that userspace can deal with sane > name/value pairs. > > + Userspace must be prepared for the possibility that attributes > + define overlapping bit ranges. For example: > + attr1 = 'config:0-23' > + attr2 = 'config:0-7' > + attr3 = 'config:12-35' > + > Example: 'config1:1,6-10,44' > Defines contents of attribute that occupies bits 1,6-10,44 of > perf_event_attr::config1. > -- > 1.7.10.4 >