Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755085Ab3GASyB (ORCPT ); Mon, 1 Jul 2013 14:54:01 -0400 Received: from mail-pb0-f42.google.com ([209.85.160.42]:44487 "EHLO mail-pb0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754744Ab3GASyA (ORCPT ); Mon, 1 Jul 2013 14:54:00 -0400 Message-ID: <51D1D043.5030509@gmail.com> Date: Mon, 01 Jul 2013 12:53:55 -0600 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: Adrian Hunter CC: Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, Frederic Weisbecker , Jiri Olsa , Mike Galbraith , Namhyung Kim , Paul Mackerras , Peter Zijlstra , Stephane Eranian Subject: Re: [PATCH V2 12/15] perf tools: allow non-matching sample types References: <1372319707-13892-1-git-send-email-adrian.hunter@intel.com> <1372319707-13892-13-git-send-email-adrian.hunter@intel.com> <51CC6AAF.4030404@gmail.com> <51D14CB6.206@intel.com> In-Reply-To: <51D14CB6.206@intel.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1323 Lines: 30 On 7/1/13 3:32 AM, Adrian Hunter wrote: > Snip > >> >> While this works for a combined S/W and tracepoint events session, I do not >> like promoting sample types to the minimum compatible level for all events >> in the session. perf needs to allow each event to have its own sample_type >> and not force a minimal compatibility. > > Why? The impact is small. The kernel API is completely unchanged. I'd like to see libperf become a stable, usable library - usable by more than the perf binary and its builtin commands. I have already done this once for a daemon, and it was a PITA to get the specific use functional without memory leaks/growth in the libperf part. With respect to this specific patch it means appropriate flexibility in the data collected for events. ie., each event can have its own sample_type. For example if the tracepoint already contains task information TID is not needed - and IP may not be wanted either. The code processing the samples should not require all events to have some minimum data format - that just wastes buffer space. David -- 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/