From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752681AbbETNxl (ORCPT ); Wed, 20 May 2015 09:53:41 -0400 Received: from mail.kernel.org ([198.145.29.136]:41101 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752324AbbETNxj (ORCPT ); Wed, 20 May 2015 09:53:39 -0400 Date: Wed, 20 May 2015 10:53:34 -0300 From: Arnaldo Carvalho de Melo To: Martin =?utf-8?B?TGnFoWth?= Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Paul Mackerras , Peter Zijlstra Subject: Re: [PATCH] perf: fix wrong DEBUG configuration Message-ID: <20150520135333.GE2955@kernel.org> References: <555B3D6F.6000301@suse.cz> <20150519140422.GJ13946@kernel.org> <555C871B.90900@suse.cz> <20150520131748.GC2955@kernel.org> <555C8C41.1080608@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <555C8C41.1080608@suse.cz> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Wed, May 20, 2015 at 03:29:37PM +0200, Martin Liška escreveu: > On 05/20/2015 03:17 PM, Arnaldo Carvalho de Melo wrote: > >Em Wed, May 20, 2015 at 03:07:39PM +0200, Martin Liška escreveu: > >>Currently, GCC optimizes -O6 same as -O3 level. Right optimize debugging > >>experience is given by passing -Og to compiler. > >Is this is this -Og available in old gcc versions? When was it > >introduced? Do you know? > GCC 4.8.0 is the first version capable of the option: https://gcc.gnu.org/gcc-4.8/changes.html. > That can be problematic, which GCC version do you support in linux/perf? So the rule has been: What are the kernel requirements for the toolchain? tools/perf/ should build with that. Looking at the kernel's README, that is... ------------- COMPILING the kernel: - Make sure you have at least gcc 3.2 available. For more information, refer to Documentation/Changes. -------------- The oldest toolchain I personally test from time to time is: [acme@rhel5 ~]$ rpm -q gcc make binutils gcc-4.1.2-55.el5 make-3.81-3.el5 binutils-2.17.50.0.6-26.el5 [acme@rhel5 ~]$ - Arnaldo