Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964890AbVL1TfB (ORCPT ); Wed, 28 Dec 2005 14:35:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964891AbVL1TfB (ORCPT ); Wed, 28 Dec 2005 14:35:01 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:59832 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S964890AbVL1TfA (ORCPT ); Wed, 28 Dec 2005 14:35:00 -0500 Subject: Re: [patch 00/2] improve .text size on gcc 4.0 and newer compilers From: Arjan van de Ven To: Linus Torvalds Cc: Ingo Molnar , lkml , Andrew Morton , Matt Mackall In-Reply-To: References: <20051228114637.GA3003@elte.hu> Content-Type: text/plain Date: Wed, 28 Dec 2005 20:34:54 +0100 Message-Id: <1135798495.2935.29.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit X-Spam-Score: -2.8 (--) X-Spam-Report: SpamAssassin version 3.0.4 on pentafluge.infradead.org summary: Content analysis details: (-2.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.8 ALL_TRUSTED Did not pass through any untrusted hosts X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 992 Lines: 27 > > The forced inlining is not just a good idea. Several versions of gcc would > NOT COMPILE the kernel without it. yup that's why the patch only does it for gcc4, in which the inlining heuristics finally got rewritten to something that seems to resemble sanity... > Also, the inlining patch apparently makes code larger in some cases, so > it's not even a unconditional win. .... as long as you give the inlining algorithm enough information. -fno-unit-at-a-time prevents gcc from having the information, and the decisions it makes are then less optimal... (unit-at-a-time allows gcc to look at the entire .c file, eg things like number of callers etc etc, disabling that tells gcc to do the .c file as single pass top-to-bottom only) - 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/