Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965078AbVLOAl1 (ORCPT ); Wed, 14 Dec 2005 19:41:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965096AbVLOAl1 (ORCPT ); Wed, 14 Dec 2005 19:41:27 -0500 Received: from mx1.redhat.com ([66.187.233.31]:1221 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S965078AbVLOAl0 (ORCPT ); Wed, 14 Dec 2005 19:41:26 -0500 Date: Wed, 14 Dec 2005 19:40:06 -0500 From: Dave Jones To: Jesper Juhl Cc: Adrian Bunk , Andrew Morton , torvalds@osdl.org, linux-kernel@vger.kernel.org Subject: Re: [2.6 patch] offer CC_OPTIMIZE_FOR_SIZE only if EXPERIMENTAL Message-ID: <20051215004006.GA19354@redhat.com> Mail-Followup-To: Dave Jones , Jesper Juhl , Adrian Bunk , Andrew Morton , torvalds@osdl.org, linux-kernel@vger.kernel.org References: <20051214191006.GC23349@stusta.de> <20051214140531.7614152d.akpm@osdl.org> <20051214221304.GE23349@stusta.de> <9a8748490512141418w2a3811a9iffe83b5f285e2910@mail.gmail.com> <9a8748490512141428q29f39ca5x66d2c52e22aa9208@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9a8748490512141428q29f39ca5x66d2c52e22aa9208@mail.gmail.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1307 Lines: 29 On Wed, Dec 14, 2005 at 11:28:13PM +0100, Jesper Juhl wrote: > I should probably back this up with *why* it boggles my mind. > > -Os has been in EMBEDDED for ages, so it's not been tested by the > majority of users with the wide range of compilers etc that people > use. Fedora has had this enabled most of the time for x86, x86-64, ia64, s390, s390x, ppc32 and ppc64 for a long time. From time to time when a gcc bug has been tickled it's been disabled again until its been worked out, but for the most part, it's been a complete non-event wrt regressions. In the ~2 years that we've had it enabled I recall 2-3 occasions where it broke something badly (and it was really noticable, like "networking doesn't work any more", or "x86-64 stopped booting"[1]), and once or twice when moving to a newer gcc point release, it tripped an ICE. The RHEL4 kernel has also been built this way since day 1. Dave [1] In that particular case, it was broken asm-x86-64/ macros that just happened to work at -O2 by chance, so it actually found latent bugs. - 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/