Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754659AbYJZNQV (ORCPT ); Sun, 26 Oct 2008 09:16:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752566AbYJZNQM (ORCPT ); Sun, 26 Oct 2008 09:16:12 -0400 Received: from mx2.redhat.com ([66.187.237.31]:40908 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752285AbYJZNQL (ORCPT ); Sun, 26 Oct 2008 09:16:11 -0400 To: =?us-ascii?Q?=3D=3FISO-8859-1=3FQ=3FFr=3DE9d=3DE9ric=5FWeisbecker=3F?= =?us-ascii?Q?=3D?= Cc: =?us-ascii?Q?=3D=3FISO-8859-1=3FQ=3FT=3DF6r=3DF6k=5FEdwin=3F=3D?= , mingo@elte.hu, srostedt@redhat.com, a.p.zijlstra@chello.nl, sandmann@daimi.au.dk, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/4] Add support for userspace stacktraces in tracing/iter_ctrl References: <1223817124-27239-1-git-send-email-edwintorok@gmail.com> <1223817124-27239-3-git-send-email-edwintorok@gmail.com> From: fche@redhat.com (Frank Ch. Eigler) Date: Sun, 26 Oct 2008 09:15:42 -0400 In-Reply-To: (fweisbec@gmail.com's message of "Sun, 26 Oct 2008 05:05:48 +0100") Message-ID: User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 786 Lines: 22 "=?ISO-8859-1?Q?Fr=E9d=E9ric_Weisbecker?=" writes: > [...] >> +/* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */ >> + >> +struct stack_frame { >> + const void __user *next_fp; >> + unsigned long return_address; >> +}; > [...] To what extent does this actually work, and on which architectures? While the kernel appears willing to sacrifice some performance for functionality by building with frame pointers at the drop of a tracing hat, userspace is not like that. - FChE -- 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/