From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756158AbaIIJLt (ORCPT ); Tue, 9 Sep 2014 05:11:49 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:58819 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755354AbaIIJLs (ORCPT ); Tue, 9 Sep 2014 05:11:48 -0400 Date: Tue, 9 Sep 2014 11:11:38 +0200 From: Peter Zijlstra To: Alexander Shishkin Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Robert Richter , Frederic Weisbecker , Mike Galbraith , Paul Mackerras , Stephane Eranian , Andi Kleen , kan.liang@intel.com Subject: Re: [PATCH v4 19/22] perf: Add infrastructure for using AUX data in perf samples Message-ID: <20140909091138.GB19379@twins.programming.kicks-ass.net> References: <1408538179-792-1-git-send-email-alexander.shishkin@linux.intel.com> <1408538179-792-20-git-send-email-alexander.shishkin@linux.intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="yBpClG5lv0ksn6ne" Content-Disposition: inline In-Reply-To: <1408538179-792-20-git-send-email-alexander.shishkin@linux.intel.com> 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 --yBpClG5lv0ksn6ne Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 20, 2014 at 03:36:16PM +0300, Alexander Shishkin wrote: > AUX data can be used to annotate other perf events by including it in > sample records when PERF_SAMPLE_AUX flag is set. In this case, a kernel > counter is created for each such event and trace data is retrieved > from it and stored in the perf data stream. >=20 > To this end, new attribute fields are added: > * aux_sample_type: specify PMU on which the AUX data generating event > is created; > * aux_sample_config: event config (maps to attribute's config field), > * aux_sample_size: size of the sample to be written. >=20 > This kernel counter is configured similarly to its "main" event with > regards to filtering (exclude_{hv,idle,user,kernel}) and enabled state > (disabled, enable_on_exec) to make sure that we don't get out of context > AUX traces. WHY? Why would we want to do this? This doesn't tell me why I should want this or even consider it. Convince me I want to read the patch. --yBpClG5lv0ksn6ne Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJUDsRKAAoJEHZH4aRLwOS6Wb0QAKmYle8UVzDO/kZvodWhjE0C c1Bat07TPhlFLjBDoX06qiQGXEYK1Yt1w4Cs6hMQvMBaTSkX98zTEPC1qKO7TZMy wZfQ+wL+ouY50+uj9og4zHeSf4x65auSQ3Nr521vZxK4zGXqdU/RVRN1YaXqbz86 cCOindCdAB5e7dfLIOzGjOr1zG0dCLUlS4uQ5mR1MR0GxSa2o2xMZwrdkV9uJNlI Rk8tEdXn1G6WzBJ/wZwKolS+7+ekAN9b3QTuZta3v6qoiO03hrm6SyZDU/8+p/g9 4jlWighndTZYl7HDKuDh45kTk7eZgJ32Pf6P0OnszSaPG8eqpybj7h2M74JUsRM+ JqFmJXfFQjiU6SL8nSksRD1N6I5ub2uvwpQukWOip9j7WQDI59Ub2Ce0d8IvlhHh ZJBGIYulBBNKh7egiB9Pp7BxIYC9FfPvyvrBw8K8uPH0MmO2STIiZoqv6Hdy54BJ PLXnClkHzwOYbfT8Ss2R7tdEWLQ5DP63liP/gLghu5yJPFcQEp+yTMMWYa9wmeHu 893VM7wnP8fsasEXbyWjr3hzaXTLo6JfEA9H00SNsgIUh/osxFubI15oQ6/mz5tx QdejsUf0aKiUsjxk3A7Oy69xt6l+ktI7zHAglngIa7wNkq9cZKPS68fG5O3rSyX+ YXVsTROv1OS26XjXmdzu =h8g1 -----END PGP SIGNATURE----- --yBpClG5lv0ksn6ne--