Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965048AbVL2Hli (ORCPT ); Thu, 29 Dec 2005 02:41:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932575AbVL2Hlh (ORCPT ); Thu, 29 Dec 2005 02:41:37 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:13784 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S932572AbVL2Hlh (ORCPT ); Thu, 29 Dec 2005 02:41:37 -0500 Date: Thu, 29 Dec 2005 08:41:07 +0100 From: Ingo Molnar To: Krzysztof Halasa Cc: Linus Torvalds , Arjan van de Ven , lkml , Andrew Morton , Matt Mackall Subject: Re: [patch 00/2] improve .text size on gcc 4.0 and newer compilers Message-ID: <20051229074107.GB20177@elte.hu> References: <20051228114637.GA3003@elte.hu> <1135798495.2935.29.camel@laptopd505.fenrus.org> <20051228212313.GA4388@elte.hu> <20051228214845.GA7859@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL autolearn=no SpamAssassin version=3.0.3 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1003 Lines: 27 * Krzysztof Halasa wrote: > Ingo Molnar writes: > > >> gcc version 4.0.2 20051109 (Red Hat 4.0.2-6) > > > another thing: i wanted to decrease the size of -Os > > (CONFIG_CC_OPTIMIZE_FOR_SIZE) kernels, which e.g. Fedora uses too (to > > keep the icache footprint down). > > Remember the above gcc miscompiles the x86-32 kernel with -Os: > > https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=173764 i'm not sure what the point is. There was no sudden rush of -Os related bugs when Fedora switched to it for the kernel, and the 35% code-size savings were certainly worth it in terms of icache footprint. Yes, -Os is a major change for how the compiler works, and the kernel is a major piece of software. Ingo - 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/