Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754148AbaBZUPF (ORCPT ); Wed, 26 Feb 2014 15:15:05 -0500 Received: from mail-pd0-f169.google.com ([209.85.192.169]:63774 "EHLO mail-pd0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752209AbaBZUPC (ORCPT ); Wed, 26 Feb 2014 15:15:02 -0500 Message-ID: <530E4B42.5090401@gmail.com> Date: Wed, 26 Feb 2014 13:14:58 -0700 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: Andy Lutomirski CC: Andi Kleen , Stephane Eranian , "Yan, Zheng" , LKML , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo Subject: Re: [PATCH v3 00/14] perf, x86: Haswell LBR call stack support References: <1392703661-15104-1-git-send-email-zheng.z.yan@intel.com> <530D53EF.9090706@amacapital.net> <20140226185513.GL22728@two.firstfloor.org> <530E3E47.8010205@gmail.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/26/14, 12:25 PM, Andy Lutomirski wrote: > On Wed, Feb 26, 2014 at 11:19 AM, David Ahern wrote: >> On 2/26/14, 11:59 AM, Andy Lutomirski wrote: >> >>> I wonder if anyone who uses perf for userspace profiling *ever* uses >>> FP and gets away with it. There's precious little userspace software >>> compiled with frame pointers these days on most architectures. >> >> >> yes and yes. With control over the entire stack we are making sure >> frame-pointers are enabled as much as possible. >> > > I'm curious why. Is there some reason not to enable frame pointers? fp method has much less overhead than dwarf, and good, clear callchains are important. > > Maybe this should be a config option. Anyone using a standard distro > is running a nearly completely frame-pointer-omitted userspace these > days. Does WRL or Yocto fall into that 'standard distro' comment? Fairly easy to enable frame-pointers. David -- 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/