Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752162Ab2H1ReI (ORCPT ); Tue, 28 Aug 2012 13:34:08 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:60717 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751167Ab2H1ReG (ORCPT ); Tue, 28 Aug 2012 13:34:06 -0400 Message-ID: <503D00D1.9070308@fb.com> Date: Tue, 28 Aug 2012 10:33:05 -0700 From: Arun Sharma User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:14.0) Gecko/20120713 Thunderbird/14.0 MIME-Version: 1.0 To: Peter Zijlstra CC: LKML , Jiri Olsa , Arnaldo Carvalho de Melo , Benjamin Redelings , Corey Ashford , Cyrill Gorcunov , "Frank Ch. Eigler" , Frederic Weisbecker , Ingo Molnar , Masami Hiramatsu , Paul Mackerras , Robert Richter , Stephane Eranian , Tom Zanussi , Ulrich Drepper Subject: Re: perf backtraces off-by-1 References: <5037FC9F.3090603@fb.com> <1345997415.2296.0.camel@laptop> <503A6273.9090702@fb.com> <1346171643.2296.8.camel@laptop> In-Reply-To: <1346171643.2296.8.camel@laptop> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.18.254] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.7.7855,1.0.431,0.0.0000 definitions=2012-08-28_06:2012-08-28,2012-08-28,1970-01-01 signatures=0 X-Proofpoint-Spam-Reason: safe Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 926 Lines: 26 On 8/28/12 9:34 AM, Peter Zijlstra wrote: >> It used to look like this: >> >> http://git.savannah.gnu.org/gitweb/?p=libunwind.git;a=commitdiff;h=92cc7fd78a5a79c4bb5f85bfb7d7fb025df9cd5a > > Hmm, that's not too bad, but a long stretch from pretty ;-) > > How would you 'encode' this in the perf callchain data? > >> These days we just look at dwarf augmentation string: >> >> http://git.savannah.gnu.org/gitweb/?p=libunwind.git;a=blob;f=src/dwarf/Gfde.c;h=8659624b0320c514057861a259b6efe1b605bbf3;hb=HEAD#l189 > > Right, except of course we don't have that in kernel.. > The ip-- transformation could happen in user space. The kernel doesn't have to know any of this :) -Arun -- 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/