From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: Two questions on perf dwarf callchains Date: Wed, 22 Jan 2014 18:55:29 +0100 Message-ID: <20140122175529.GX20765@two.firstfloor.org> References: <1389954083.1125.23.camel@nb-andreolini.mat.unimo.it> <87d2jq1i7q.fsf@tassilo.jf.intel.com> <1390001852.8555.8.camel@nb-andreolini> <20140118044203.GR20765@two.firstfloor.org> <1390401626.22168.4.camel@nb-andreolini.mat.unimo.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from one.firstfloor.org ([193.170.194.197]:36592 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751359AbaAVRzb (ORCPT ); Wed, 22 Jan 2014 12:55:31 -0500 Content-Disposition: inline In-Reply-To: <1390401626.22168.4.camel@nb-andreolini.mat.unimo.it> Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: Mauro Andreolini Cc: Andi Kleen , linux-perf-users@vger.kernel.org On Wed, Jan 22, 2014 at 03:40:26PM +0100, Mauro Andreolini wrote: > Il giorno sab, 18/01/2014 alle 05.42 +0100, Andi Kleen ha scritto: > > The dwarf information should be present unless explicitely disabled. > > It's either a libunwind or compiler problem. You could file a gcc bug > > I suppose. Also check if gdb can backtrace through it. If that works > > it's likely unwind. > gdb can backtrace perfectly through ls -lR /. Also, recompiling the You tested it on the same IP as perf failed on, correct? It will depend on the exact location. > whole system with -fno-omit-frame-pointer makes perf record & report > work like a charm. So I guess it must be the unwinder. Please report it to the libunwind developers. -Andi