From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757493AbYKWTnS (ORCPT ); Sun, 23 Nov 2008 14:43:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752585AbYKWTnG (ORCPT ); Sun, 23 Nov 2008 14:43:06 -0500 Received: from one.firstfloor.org ([213.235.205.2]:56006 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752318AbYKWTnE (ORCPT ); Sun, 23 Nov 2008 14:43:04 -0500 To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Thomas Gleixner , Peter Zijlstra , Theodore Tso , Arjan van de Ven , Steven Rostedt Subject: Re: [PATCH 4/4] trace: profile all if conditionals From: Andi Kleen References: <20081121071213.365288293@goodmis.org> <20081121071328.462456268@goodmis.org> Date: Sun, 23 Nov 2008 20:43:07 +0100 In-Reply-To: <20081121071328.462456268@goodmis.org> (Steven Rostedt's message of "Fri, 21 Nov 2008 02:12:17 -0500") Message-ID: <87iqqei5ys.fsf@basil.nowhere.org> 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 Steven Rostedt writes: > > Miss means the branch was not taken. Hit means the branch was taken. > The percent is the percentage the branch was taken. I'm not sure the results are very useful? What would you do with it? It seems like a very special case of gcov, but I think I would rather have the full thing (patches in -mm I think) > This adds a significant amount of overhead and should only be used > by those analyzing their system. Often this can be also done using CPU performance counters. Might be a cheaper option. -Andi -- ak@linux.intel.com