Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752661Ab3IENKx (ORCPT ); Thu, 5 Sep 2013 09:10:53 -0400 Received: from mail-la0-f45.google.com ([209.85.215.45]:39851 "EHLO mail-la0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751993Ab3IENKw (ORCPT ); Thu, 5 Sep 2013 09:10:52 -0400 MIME-Version: 1.0 In-Reply-To: <20130905124508.GE9696@mudshark.cambridge.arm.com> References: <1378317854-25965-1-git-send-email-jean.pihet@linaro.org> <1378317854-25965-4-git-send-email-jean.pihet@linaro.org> <20130905124508.GE9696@mudshark.cambridge.arm.com> Date: Thu, 5 Sep 2013 15:10:51 +0200 Message-ID: Subject: Re: [PATCH 3/3] perf: parse the .debug_frame section in case .eh_frame is not present From: Ard Biesheuvel To: Will Deacon Cc: Jean Pihet , "linaro-kernel@lists.linaro.org" , "patches@linaro.org" , Michael Hudson-Doyle , "linux-kernel@vger.kernel.org" , Jiri Olsa , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1345 Lines: 41 On 5 September 2013 14:45, Will Deacon wrote: > Hi Jean, > > [adding Michael, since I know he was interested in this] > > On Wed, Sep 04, 2013 at 07:04:14PM +0100, Jean Pihet wrote: >> On ARM the debug info is not present in the .eh_frame sections but >> instead in .debug_frame. >> Use libunwind to load and parse the debug info. > > How have you tested this? Regardless of whether or not I apply this patch, I > get the same (broken/truncated) callchains for userspace in perf report. Same here: I have applied these patches against 3.11 running on a Calxeda Highbank, and I never get more than a single entry for the userland part of the call stack. > > E.g. the following stupid program (built with -O0 -g): > [...] > > Gives me an incomplete callchain: > > # Overhead Command Shared Object Symbol > # ........ ........ ................. ............................... > # > 0.00% unwindme unwindme [.] bar > | > --- bar > I get exactly the same results, just bar and nothing below. -- Ard. -- 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/