Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933911Ab2JZPjO (ORCPT ); Fri, 26 Oct 2012 11:39:14 -0400 Received: from mail-da0-f46.google.com ([209.85.210.46]:33420 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933818Ab2JZPjM (ORCPT ); Fri, 26 Oct 2012 11:39:12 -0400 Subject: Re: [PATCH 00/11] perf tool: Add PERF_SAMPLE_READ sample read support From: Namhyung Kim To: Jiri Olsa Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, Arnaldo Carvalho de Melo , Ingo Molnar , Paul Mackerras , Corey Ashford , Frederic Weisbecker In-Reply-To: <20121026102336.GA1067@krava.brq.redhat.com> References: <1350743599-4805-1-git-send-email-jolsa@redhat.com> <87txti81i2.fsf@sejong.aot.lge.com> <1351242885.16863.0.camel@twins> <20121026102336.GA1067@krava.brq.redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Sat, 27 Oct 2012 00:39:06 +0900 Message-ID: <1351265946.1619.20.camel@leonhard> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1876 Lines: 56 2012-10-26 (금), 12:23 +0200, Jiri Olsa: > On Fri, Oct 26, 2012 at 11:14:45AM +0200, Peter Zijlstra wrote: > > I haven't actually looked at the implementation, but I understood it to > > be a group modifier, not an event modifier. > > we might want to be able to use PERF_SAMPLE_READ for single event > same as for groups What is the merits of doing it? > > the difference between single event and group 'S' modifier: > > $ ./perf record -e 'cycles:S' ls > - records 'cycles' samples and read period value via PERF_SAMPLE_READ > > $ ./perf record -e '{cycles,cache-misses}:S' > - samples just on 'cycles' samples and read both period values > (cycles and cache-misses) via PERF_SAMPLE_READ group format > > $ ./perf record -e '{cycles,cache-misses}:S,instructions' ls > $ ./perf record -e '{cycles:S,cache-misses},instructions' ls > $ ./perf record -e 'cycles:S,instructions' ls > - non matching sample_type > > hm, thats the unique sample_type issue again ;) Once we set > PERF_SAMPLE_READ for event or group, we need to set it for > all other events in session, otherwise the report fails Sorry, I don't understand why we need to set it for all events. Just setting it for a group is not sufficient? Please shed some light on this. Thanks, Namhyung > > sooo, it looks like: > - global record '-S' option instead, setting PERF_SAMPLE_READ sample type > globaly for all events > - and ':S' group modifier to enable sampling only on leader > with group format reading for the rest of the group > - ':S' group modifier alone would imply -S > > How about that? > > thanks, > jirka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/