From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932673AbbFENYN (ORCPT ); Fri, 5 Jun 2015 09:24:13 -0400 Received: from mga11.intel.com ([192.55.52.93]:53557 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932520AbbFENYK (ORCPT ); Fri, 5 Jun 2015 09:24:10 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,558,1427785200"; d="scan'208";a="737705025" Message-ID: <5571A268.3050207@intel.com> Date: Fri, 05 Jun 2015 16:21:44 +0300 From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Arnaldo Carvalho de Melo , Ingo Molnar CC: linux-kernel@vger.kernel.org, Borislav Petkov , David Ahern , Don Zickus , Frederic Weisbecker , Jiri Olsa , Josef Bacik , kernel-team@fb.com, Luigi Semenzato , Martin Liska , Namhyung Kim , "Nam T . Nguyen" , Paul Mackerras , Peter Zijlstra , Simon Que , Stephane Eranian Subject: Re: [GIT PULL 00/37] perf/core improvements and fixes References: <1432658888-7993-1-git-send-email-acme@kernel.org> <20150527073847.GA30999@gmail.com> <20150527123532.GQ17970@kernel.org> In-Reply-To: <20150527123532.GQ17970@kernel.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27/05/15 15:35, Arnaldo Carvalho de Melo wrote: > Em Wed, May 27, 2015 at 09:38:47AM +0200, Ingo Molnar escreveu: >> * Arnaldo Carvalho de Melo wrote: >>> New features: > >>> - Intel PT support, should be complete now and possible to test it with what we >>> already have in the kernel, go, test it and report problems on lkml, I'm sure >>> Adrian will chime in if something doesn't work as documented. (Adrian Hunter) > >> So how can people follow your request? > > First by having access to a machine with these hardware features, which, > for one, I have no easy access to right now :-\ > >> The changelogs are minimal, sometimes they only say: > > They improved over time, over the many resubmits Adrian made, so some > progress was made on this front. > >> From 7a84d68975f34c912cb6ec8adb3c1869c15b5c36 Mon Sep 17 00:00:00 2001 >> From: Adrian Hunter >> Date: Fri, 22 May 2015 14:54:04 +0300 >> Subject: [PATCH] perf tools: Add Intel PT support > >> Add support for Intel Processor Trace. > >> there's almost zero comments added by these commits. > > I shouldn't have let some pass, granted. > >> This commit: >> >> 928541b6f51f perf tools: Take Intel PT into use >> >> adds 'some documentation' under ./Documentation/intel-pt.txt, but that text >> doesn't actually give any high level description, it doesn't give _any_ way for a >> user to discover Intel PT support on his own - unless he already knows it, which >> is kind of circular. > >> It doesn't describe which CPUs support Intel PT, what it is, how are people >> supposed to use it, what the high level capabilities and limitations are, etc. >> etc. > >> So this stuff is user and developer hostile at the moment. We can push this >> towards Linus only if this becomes _much_ more user and developer friendly. Near >> zero documentation and near zero comments in the code don't cut it really. > > Adrian, can you try to address this further, please? > > Something like a handholding session, so that we don't have to dig thru > all the csets or patch series cover letters, telling: > > 1. What hardware one has to have to be able to test it > > 2. First command to use > > 3. What will be generated, how much space (a lot?) it will use on the > perf.data file, etc. > > 5. What commands have to be used on this perf.data file and what to > expect from it. > > I.e. a HOWTO that starts with a as short as possible description on how > to use it for the very first time, for people never exposed to Intel PT > but that can benefit from using it. I sent the patches again a week ago, but perhaps no one noticed. They are here: http://marc.info/?l=linux-kernel&m=143290658028132 Comments welcome :-)