From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932444AbbJ0Nv7 (ORCPT ); Tue, 27 Oct 2015 09:51:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46465 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932203AbbJ0Nv5 (ORCPT ); Tue, 27 Oct 2015 09:51:57 -0400 Date: Tue, 27 Oct 2015 14:51:54 +0100 From: Jiri Olsa To: Arnaldo Carvalho de Melo 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: <20151027135154.GA21699@krava.brq.redhat.com> 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> <20151027134440.GB9405@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151027134440.GB9405@kernel.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 27, 2015 at 10:44:40AM -0300, Arnaldo Carvalho de Melo wrote: > 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? nope ;-) it's just the read function perf_event__read_stat_config takes the 'struct perf_stat_config *' and updates it based on the event data. we would need to change the code to be more generic.. but as you said, it's future ;-) jirka