From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758858AbZBTAhY (ORCPT ); Thu, 19 Feb 2009 19:37:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752346AbZBTAhJ (ORCPT ); Thu, 19 Feb 2009 19:37:09 -0500 Received: from fg-out-1718.google.com ([72.14.220.158]:22015 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751536AbZBTAhH (ORCPT ); Thu, 19 Feb 2009 19:37:07 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=BEp/AjlpMb6Mazf4Jn/xWoAc1h6QUTkFpSLn9rJWvzG3EU6mp4FlIaN6kd2ebWsCXR A/YI3wZu0q21qIjT+W1uFdAYUlL6qYk7DsGMhN3o2hW21sWnd+y7shdZkJdJZq2mmLhy R9IGORFqtEVRl/QbsB1rvy8k9TMKmo9yeqVQI= MIME-Version: 1.0 In-Reply-To: <1234952753.10531.48.camel@andreas-laptop> References: <1234722028-8110-1-git-send-email-andr345@gmail.com> <200902181528.29697.rusty@rustcorp.com.au> <1234952753.10531.48.camel@andreas-laptop> Date: Fri, 20 Feb 2009 01:37:05 +0100 Message-ID: Subject: Re: [RFC PATCH 0/6] module, kbuild: Faster boot with custom kernel. From: Andreas Robinson To: Kay Sievers Cc: Rusty Russell , sam@ravnborg.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ok, I've run some tests now and the results are not quite what I expected. There are 3 cases: Case 1 used a monolithic kernel with a full set of 95 inked-in external modules. Case 2 loaded a single mega-module (same set of 95 modules of course) while case 3 looped through a list of pathnames and called insmod on each one. The test machine boots the monolithic kernel in 6.27 seconds. This is about 0.5 seconds faster than the other two cases, that were roughly equal. The setup: HP pavillion dv6300 laptop, TL-56 Turion 64 X2 CPU @1.8GHz, 5400 RPM 2.5" Seagate SATA drive Linux 2.6.29-rc5, with the .config derived from the generic Ubuntu 8.10 kernel. All three cases had a minimal initramfs with busybox, insmod and an init script that only inserted modules and then halted. IOW, no root fs was mounted. The results: 1. Monolithic: 6.27 s, (0.22). bzImg=3419 kB ramfs=515 kB 2. Megamodule: 6.80 s, (0.16). bzImg=2297 kB ramfs=1783 kB 3. Insmod list: 6.83 s, (0.07). bzImg=2297 kB ramfs=1942 kB 10 samples were taken in each case. Standard deviations are in parenthesis. The measured times are printk timestamps from a dummy module inserted last. Reading these benchmark results I can only conclude that my work is useless and life has no meaning. So, what's missing or been done wrong here? I expected the difference between monolithic and modular to be greater to be honest. Cheers, Andreas