From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753940Ab0E1HBB (ORCPT ); Fri, 28 May 2010 03:01:01 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:53249 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752175Ab0E1HBA (ORCPT ); Fri, 28 May 2010 03:01:00 -0400 Date: Fri, 28 May 2010 09:00:26 +0200 From: Ingo Molnar To: Linus Torvalds Cc: Paul Mackerras , linux-kernel@vger.kernel.org, Peter Zijlstra , Arnaldo Carvalho de Melo , Fr?d?ric Weisbecker , Steven Rostedt , Thomas Gleixner , Andrew Morton Subject: Re: [GIT PULL, v2] perf changes Message-ID: <20100528070026.GA31058@elte.hu> References: <20100524192531.GA15614@elte.hu> <20100525002221.GA30395@drongo> <20100525135200.GA21462@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: 1.0 X-ELTE-SpamLevel: s X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=1.0 required=5.9 tests=BAYES_50 autolearn=no SpamAssassin version=3.2.5 1.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.4993] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Linus Torvalds wrote: > On Tue, 25 May 2010, Ingo Molnar wrote: > > > > 75 files changed, 1847 insertions(+), 3147 deletions(-) > > I was excited by this ("A code _reduction_! Will wonders never cease?"), but > it turns out that all of the reduction was due to removing some unused > utility functions from the user-level tools. Simple things first and maybe it turns into a habit! > The actual kernel still grew: > > 32 files changed, 1327 insertions(+), 964 deletions(-) > > oh well. Merged anyway. Hey, while i have to admit to being a member of the infinitely large group of kernel developers working hard to ensure that the kernel's size follows Moore's Law - this time i beg to differ, as we _did_ manage to shrink the kernel! ;-) Here's the before/after vmlinux comparison: (x86 defconfig, 64-bit): vmlinux: text data bss dec hex filename ....................................................... cad719d (before): 8441843 1281100 983876 10706819 a35f83 vmlinux c5617b2 ( after): 8417488 1277724 983876 10679088 a2f330 vmlinux ....................................................... -24.35K -3.37K -0.28% -0.26% Ob'Suggestion: we could help debloating efforts by officially declaring to take provably-debloating patches up to -rc4? (with a vmlinux comparison mandated in the changelog or such) Debloating patches tend to reduce complexity, and hence are more regression-resistent. (They are also rare, so it's not like we would be risking a flood of patches.) That would be a clever way to redirect the creative energies of kernel developers who are otherwise bored by -rc1's legendary stability and always try to sneak further features upstream post -rc1. Such a policy would mean that while the merge window for bloating patches is a strict ~1.5 weeks, the merge window for debloating patches would be a generous ~1.5 months. Maybe such a mild hint would help propagate the idea some more. Dunno - just an idea, Ingo