From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753422AbZHMLeO (ORCPT ); Thu, 13 Aug 2009 07:34:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752725AbZHMLeL (ORCPT ); Thu, 13 Aug 2009 07:34:11 -0400 Received: from casper.infradead.org ([85.118.1.10]:45969 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752636AbZHMLeJ (ORCPT ); Thu, 13 Aug 2009 07:34:09 -0400 Subject: Re: [PROBLEM] perf report is broken in latest linus git From: Peter Zijlstra To: Pekka Enberg Cc: Ingo Molnar , Arnaldo Carvalho de Melo , paulus@samba.org, linux-kernel@vger.kernel.org In-Reply-To: <1250156837.8141.4.camel@penberg-laptop> References: <1250155708.6052.2.camel@penberg-laptop> <20090813093648.GA22762@elte.hu> <1250156837.8141.4.camel@penberg-laptop> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Thu, 13 Aug 2009 13:33:32 +0200 Message-Id: <1250163212.5241.9.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.26.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2009-08-13 at 12:47 +0300, Pekka Enberg wrote: > Hi Ingo, > > On Thu, 2009-08-13 at 11:36 +0200, Ingo Molnar wrote: > > * Pekka Enberg wrote: > > > > > Latest Linus git kernel with -rc4 perf userspace: > > > > > > penberg@penberg-laptop:~/testing/jato$ perf record -f jato HelloWorldSwing > > > [ perf record: Captured and wrote 1.402 MB perf.data (~61261 samples) ] > > > > > > penberg@penberg-laptop:~/testing/jato$ perf report --sort comm,dso,symbol|head -30 > > > # Samples: 60457 > > > # > > > # Overhead Command Shared Object Symbol > > > # ........ ....... ....................................... ...... > > > # > > > > > > [ Note: the jato executable doesn't appear anywhere in the trace. I'm > > > pretty sure the libzip functions, for example, are from jato, not perf. ] > > > > > > 36.14% perf /home/penberg/bin/perf [.] dso__synthesize_plt_symbols > > > 35.20% perf /home/penberg/bin/perf [.] dso__new > > > 3.57% perf /home/penberg/bin/jato [.] 0x0000000000c910 > > > > Perhaps it's this commit: > > > > 4d1e00a: perf symbol: Fix symbol parsing in certain cases: use the build-id as a symlink > > > > it does not revert cleanly, so you might want to check out these two > > commits: > > > > 4d1e00a > > 4d1e00a~1 > > > > and build perf on both, and check with your anomalous perf.data > > (without changing it) whether the output makes most sense. > > The commit seems fine. Like I said, the perf.data file is busted even > with 2.6.31-rc4 userspace so I think it's a kernel bug. Hrmm, does a -tip kernel work as expected? I'll go audit the kernel changes between -rc4 and -rc5.