From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964857AbWIKFlp (ORCPT ); Mon, 11 Sep 2006 01:41:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964879AbWIKFlo (ORCPT ); Mon, 11 Sep 2006 01:41:44 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:22490 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S964857AbWIKFln (ORCPT ); Mon, 11 Sep 2006 01:41:43 -0400 Date: Mon, 11 Sep 2006 07:33:20 +0200 From: Ingo Molnar To: Daniel Walker Cc: David Howells , torvalds@osdl.org, akpm@osdl.org, benh@kernel.crashing.org, linux-kernel@vger.kernel.org, uclinux-dev@uclinux.org, Marcelo Tosatti , kai@germaschewski.name, sam@ravnborg.org Subject: Re: [PATCH 2/3] FRV: Permit __do_IRQ() to be dispensed with Message-ID: <20060911053320.GB11269@elte.hu> References: <20060908153236.21015.56106.stgit@warthog.cambridge.redhat.com> <20060908153240.21015.67367.stgit@warthog.cambridge.redhat.com> <20060909051211.GA6922@elte.hu> <1157898878.3516.2.camel@c-67-169-176-11.hsd1.ca.comcast.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1157898878.3516.2.camel@c-67-169-176-11.hsd1.ca.comcast.net> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: -2.9 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.9 required=5.9 tests=ALL_TRUSTED,AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts 0.5 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.5000] -0.1 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 * Daniel Walker wrote: > On Sat, 2006-09-09 at 07:12 +0200, Ingo Molnar wrote: > > > The real solution would be to use gcc -ffunction-sections plus ld > > --gc-sections to automatically get rid of unused global functions, at > > link time. I'm wondering how hard it would be to enhance kbuild to do > > that - x86_64 already uses -ffunction-sections (if CONFIG_REORDER), so > > the big question is how usable is ld --gc-sections. Such a feature would > > be quite important for embedded systems (and for RAM footprint in > > general) as it would save a significant amount of .text and .data. > > A patch to do this was submitted already by Marcelo Tosatti .. > > http://lkml.org/lkml/2006/6/4/169 ah, i missed that patch in the June lock validator frenzy. The results are astounding: >> vmlinux shrinks from 1090389 to 983933 bytes, or 106k (~= 10%). Andrew, Linus, Kai, Sam: a must-have feature! This saves more kernel kernel image RAM than all the other kernel shrinking efforts of the past 2 years combined - at zero cost. Ingo