From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753126AbZBQLxg (ORCPT ); Tue, 17 Feb 2009 06:53:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751334AbZBQLx2 (ORCPT ); Tue, 17 Feb 2009 06:53:28 -0500 Received: from mail-ew0-f31.google.com ([209.85.219.31]:34516 "EHLO mail-ew0-f31.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751253AbZBQLx1 (ORCPT ); Tue, 17 Feb 2009 06:53:27 -0500 MIME-Version: 1.0 In-Reply-To: References: <1234722028-8110-1-git-send-email-andr345@gmail.com> <200902170921.56789.rusty@rustcorp.com.au> Date: Tue, 17 Feb 2009 12:53:25 +0100 Message-ID: Subject: Re: [RFC PATCH 0/6] module, kbuild: Faster boot with custom kernel. From: Kay Sievers To: Andreas Robinson Cc: Rusty Russell , sam@ravnborg.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 17, 2009 at 11:42, Andreas Robinson wrote: > On Mon, Feb 16, 2009 at 11:51 PM, Rusty Russell wrote: >> >> This isn't crazy. But you'd need to benchmark against the minimal >> userspace solution: a binary with all the modules built into >> it which calls sys_init_module on each one, then does the root swizzle >> or whatever. >> >> I think you'd find the difference to be in the noise. Usual distro setups load like 100+ modules on every bootup. Modprobing and symbol-resolving is serialized and uses stop_machine(), so there might be some significant difference here when loading a huge number of modules individually. Monolithic versus modular kernels usually make about 2+ seconds difference on a recent laptop. > your're right and I'll get right on it. For distros it's probably more interesting not to get rid of the initramfs, but possibly have the mkinitrd/mkinitramfs tool to pre-link all the usual modules if faster bootup is expected. Having only the few modules pre-linked which are usually included in the initramfs, might, as Rusty expects, not make that much difference. Kay