Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965079Ab3FTJIW (ORCPT ); Thu, 20 Jun 2013 05:08:22 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:47592 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755509Ab3FTJIU (ORCPT ); Thu, 20 Jun 2013 05:08:20 -0400 Date: Thu, 20 Jun 2013 10:07:29 +0100 From: Will Deacon To: Jed Davis Cc: Peter Zijlstra , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , Russell King , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] perf: ARM: Record the user-mode PC in the call chain. Message-ID: <20130620090728.GA2842@mudshark.cambridge.arm.com> References: <20130613232111.GA12536@mozilla.com> <20130618131319.GC6801@mudshark.cambridge.arm.com> <20130620031706.GB27428@mozilla.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130620031706.GB27428@mozilla.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1232 Lines: 29 On Thu, Jun 20, 2013 at 04:17:06AM +0100, Jed Davis wrote: > On Tue, Jun 18, 2013 at 02:13:19PM +0100, Will Deacon wrote: > > On Fri, Jun 14, 2013 at 12:21:11AM +0100, Jed Davis wrote: > > > With this change, we no longer lose the innermost entry in the user-mode > > > part of the call chain. See also the x86 port, which includes the ip. > > > > > > It's possible to partially work around this problem by post-processing > > > the data to use the PERF_SAMPLE_IP value, but this works only if the CPU > > > wasn't in the kernel when the sample was taken. > > > > Thanks. I guess we need something similar for arm64 too. Could you cook a > > similar patch please? > > Done (and tested, on the ARM V8 Foundation Model). Wow, I didn't expect you to test it. Thanks! > It looked as if the powerpc and sparc ports might have similar issues, > but I haven't checked on them yet. I can extract some hardware from the pile in the corner of my flat if you want a hand with testing. Will -- 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/