From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mauro Andreolini Subject: Re: Two questions on perf dwarf callchains Date: Sat, 18 Jan 2014 00:42:52 +0100 Message-ID: <1390002172.9768.1.camel@nb-andreolini> Reply-To: mauro.andreolini@unimore.it Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp7.sms.unimo.it ([155.185.44.150]:54042 "EHLO smtp7.sms.unimo.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752638AbaARAIu (ORCPT ); Fri, 17 Jan 2014 19:08:50 -0500 Received: from host50-39-dynamic.1-87-r.retail.telecomitalia.it ([87.1.39.50]:55101 helo=[192.168.1.5]) by smtp7.sms.unimo.it with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from ) id 1W4J3t-0000DT-SY for linux-perf-users@vger.kernel.org; Sat, 18 Jan 2014 00:42:54 +0100 Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: "linux-perf-users@vger.kernel.org" [Sorry for the repost, I can't see my reply in the gmane interface] Il giorno ven, 17/01/2014 alle 12.11 -0800, Andi Kleen ha scritto: > Mauro Andreolini writes: > > file to get perf report to print the function names. > > Is this expected behaviour? How do I get perf to automatically extract > > symbols from compressed files? > > Someone would need to write the code to do that I guess. OK. > > > > To which function would 0x7facc1df12a0 match? It does not even seem to > > be in the mapped address space of "ls". I am clueless. > > The unwinder got confused. A common cause is incomplete or partially > broken dwarf unwind information. May be a compiler problem. Thanks for your time. Right now I am using gcc 4.8.2 20131219 (prerelease) and libunwind 1.1. I noticed the following compile flags: "-O2 -g -fvar-tracking-assignments". I thought that maybe optimizations like function inlining and the like would not play together with debugging info, so I changed them to "-Og -g3 -fvar-tracking-assignments" and recompiled anything, albeit with no luck. I must be missing something big here. How can I be sure to give correct dwarf unwind information? Mauro