Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752844AbdCAPh6 (ORCPT ); Wed, 1 Mar 2017 10:37:58 -0500 Received: from bombadil.infradead.org ([65.50.211.133]:37527 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752001AbdCAPhz (ORCPT ); Wed, 1 Mar 2017 10:37:55 -0500 Date: Wed, 1 Mar 2017 16:07:46 +0100 From: Peter Zijlstra To: Namhyung Kim Cc: Taeung Song , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, Jiri Olsa , Ingo Molnar , Wang Nan , Masami Hiramatsu , Jiri Olsa , kernel-team@lge.com Subject: Re: [PATCH v2 2/3] perf annotate: Introduce the new source code view Message-ID: <20170301150746.GJ6515@twins.programming.kicks-ass.net> References: <1488311993-15124-1-git-send-email-treeze.taeung@gmail.com> <1488311993-15124-3-git-send-email-treeze.taeung@gmail.com> <20170301135805.GB2690@danjae.aot.lge.com> <20170301140833.GG6515@twins.programming.kicks-ass.net> <20170301142133.GC2690@danjae.aot.lge.com> <20170301143011.GI6515@twins.programming.kicks-ass.net> <20170301145639.GA3370@danjae.aot.lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170301145639.GA3370@danjae.aot.lge.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 616 Lines: 13 On Wed, Mar 01, 2017 at 11:56:39PM +0900, Namhyung Kim wrote: > It's a kind of user experience issue. We provide the asm-only and > asm+source annotation, and I think it'd be nice to add source-only > option. And I remember that it was requested some time ago.. Thing is, an optimizing compiler -- that same beast that ensures your objdump -S output is such a garbled mess -- can generate code that becomes very hard to relate to the original source code. I'm really sceptical the source line only view is very useful; maybe if you build with -O0, but then, if you do that you're not bothered with performance.