Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964912AbVL1VRK (ORCPT ); Wed, 28 Dec 2005 16:17:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964914AbVL1VRK (ORCPT ); Wed, 28 Dec 2005 16:17:10 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:5840 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S964912AbVL1VRJ (ORCPT ); Wed, 28 Dec 2005 16:17:09 -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> <1135798495.2935.29.camel@laptopd505.fenrus.org> Content-Type: text/plain Date: Wed, 28 Dec 2005 22:17:01 +0100 Message-Id: <1135804621.8976.1.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: 1470 Lines: 33 On Wed, 2005-12-28 at 13:02 -0800, Linus Torvalds wrote: > > On Wed, 28 Dec 2005, Arjan van de Ven wrote: > > > > 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... > > Is that actually true of all gcc4 versions? I seem to remember gcc-4.0 > being a real stinker. it is... if you disable unit-at-a-time for sure. But I'm not entirely sure when this got in, if it was 4.0 or 4.1 > > (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) > > I'd still prefer to see numbers with -funit-at-a-time only. I think it's > an independent knob, and I'd be much less worried about that, because we > do know that unit-at-a-time has been enabled on x86-64 for a long time > ("forever"). So that's less of a change, I feel. the only effect I expect is more inlining actually, since we on the one hand tie gcc's hands via the forced inline, and one the other hand now give it more room to inline more. But yeah it's worth to look at for sure, even if it is to see it's getting bigger ;) - 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/