Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762610Ab2FVPcm (ORCPT ); Fri, 22 Jun 2012 11:32:42 -0400 Received: from mail-yw0-f51.google.com ([209.85.213.51]:59357 "EHLO mail-yw0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762578Ab2FVPcj (ORCPT ); Fri, 22 Jun 2012 11:32:39 -0400 Date: Fri, 22 Jun 2012 12:32:34 -0300 From: Arnaldo Carvalho de Melo To: David Ahern Cc: Namhyung Kim , Peter Zijlstra , Paul Mackerras , Ingo Molnar , LKML , Jiri Olsa Subject: Re: [RFC/PATCHSET 0/8] perf tools: Minimal build without libelf dependency (v2) Message-ID: <20120622153234.GJ17747@infradead.org> References: <1340343462-15556-1-git-send-email-namhyung@kernel.org> <1340358478.18025.51.camel@twins> <1340377510.1478.10.camel@leonhard> <4FE48CCA.2050506@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4FE48CCA.2050506@gmail.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1637 Lines: 35 Em Fri, Jun 22, 2012 at 09:18:34AM -0600, David Ahern escreveu: > On 6/22/12 9:05 AM, Namhyung Kim wrote: > >2012-06-22 (금), 11:47 +0200, Peter Zijlstra: > >>On Fri, 2012-06-22 at 14:37 +0900, Namhyung Kim wrote: > >>>And then I realized that the perf record needs to know about the > >>>build-id's anyway. :( So I implemented a poor man's version of elf > >>>parser only for parsing the build-id info. > >>Why? the very first versions didn't know about any of that nonsense :-) > >>It works just fine as long as you don't go change binaries around. > >> > >>That said, you did the work already, so no objection, just saying > >>builtids aren't that important. > >I'm not sure I understood you correctly. But 'perf record' needs to know > >about the build-id's to save them to perf.data for 'perf report' later. > >And 'perf archive' also needs to know about them to select necessary > >binaries for the session. > And build-id's are not required for report (-B option for record). > Also, the intent is for a small footprint binary for embedded > systems. On such a system I would expect binaries and libraries to > be stripped, so no point in running perf-archive. Right, build ids are not a strict requirement, its just a safeguard, when available, to prevent WTF moments at post processing time (report, annotate, etc) if different binaries are used to resolve symbols. - Arnaldo -- 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/