From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932417AbbJ0Nor (ORCPT ); Tue, 27 Oct 2015 09:44:47 -0400 Received: from mail.kernel.org ([198.145.29.136]:51703 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932203AbbJ0Noq (ORCPT ); Tue, 27 Oct 2015 09:44:46 -0400 Date: Tue, 27 Oct 2015 10:44:40 -0300 From: Arnaldo Carvalho de Melo To: Jiri Olsa Cc: Jiri Olsa , lkml , David Ahern , Ingo Molnar , Namhyung Kim , Peter Zijlstra , "Liang, Kan" Subject: Re: [PATCH 11/52] perf tools: Add stat config event Message-ID: <20151027134440.GB9405@kernel.org> References: <1445784728-21732-1-git-send-email-jolsa@kernel.org> <1445784728-21732-12-git-send-email-jolsa@kernel.org> <20151027131605.GA9405@kernel.org> <20151027133043.GA21158@krava.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151027133043.GA21158@krava.brq.redhat.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Tue, Oct 27, 2015 at 02:30:43PM +0100, Jiri Olsa escreveu: > On Tue, Oct 27, 2015 at 10:16:05AM -0300, Arnaldo Carvalho de Melo wrote: > > Em Sun, Oct 25, 2015 at 03:51:27PM +0100, Jiri Olsa escreveu: > > > Adding stat config event to pass/store stat config data, > > > so report tools (report/script) know how to interpret > > > stat data. > > > > > > The config data are stored in 'tag|value' way to allow > > > easy extension and backward compatibility. > > > > I wonder if this couldn't be renamed 'PERF_RECORD_CONFIG' and just go > > on using one of those 2^64-1 tags for the 'stat config' needs, but then > > this is just a matter of changing the name of this event, which won't > > break anything when done. > > we use this event to update 'struct perf_stat_config', > so it's kind of stat specific What makes it specific? Isn't this just tag/value? If it was generic all it would take would be for us to register a range of values (or several) to be handled by the stat config reading routine. > > Other stuff we may want to have stored like this include sysctl, sysfs > > values, kernel command line options used, etc. > > I think we could easily add record specific event for this > once it's needed.. there's plenty of free numbers in user > events area ;-) Shhh, don't ask PeterZ about it ;-) But seriously, what makes this specific? Do you envision the stat code needing 2^64-1 tags? Anyway, we can revisit this when code needing to store tag/value appears. - Arnaldo