From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262536AbTJOXYo (ORCPT ); Wed, 15 Oct 2003 19:24:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262597AbTJOXYo (ORCPT ); Wed, 15 Oct 2003 19:24:44 -0400 Received: from hermes.fachschaften.tu-muenchen.de ([129.187.202.12]:5339 "HELO hermes.fachschaften.tu-muenchen.de") by vger.kernel.org with SMTP id S262536AbTJOXYn (ORCPT ); Wed, 15 Oct 2003 19:24:43 -0400 Date: Thu, 16 Oct 2003 01:24:40 +0200 From: Adrian Bunk To: Andrew Morton Cc: linux-kernel@vger.kernel.org Subject: Re: [2.6 patch] add a config option for -Os compilation Message-ID: <20031015232440.GU17986@fs.tum.de> References: <20031015225055.GS17986@fs.tum.de> <20031015161251.7de440ab.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20031015161251.7de440ab.akpm@osdl.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 15, 2003 at 04:12:51PM -0700, Andrew Morton wrote: >... > They are small concerns really, but it does make one wonder why we should > not make this change unconditional: just switch the kernel to -Os? > > Does anyone have any (non-micro-)benchmark results which say this is a bad > idea? No benchmarks, only arguments: - it's less tested (there might be miscompilations in some part of the kernel with some supported compilers) - there might be fast path code somewhere in the kernel that becomes significantely slower with -Os - I've already seen a report for an ICE in gcc 2.95 of a user compiling kernel 2.4 with -Os [1] cu Adrian [1] http://bugs.debian.org/213497 -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed