Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753660AbZCHQAt (ORCPT ); Sun, 8 Mar 2009 12:00:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753381AbZCHQAb (ORCPT ); Sun, 8 Mar 2009 12:00:31 -0400 Received: from casper.infradead.org ([85.118.1.10]:47411 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753330AbZCHQAa (ORCPT ); Sun, 8 Mar 2009 12:00:30 -0400 Date: Sun, 8 Mar 2009 09:01:02 -0700 From: Arjan van de Ven To: Andreas Robinson Cc: Kay Sievers , Rusty Russell , sam@ravnborg.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 0/6] module, kbuild: Faster boot with custom kernel. Message-ID: <20090308090102.2db82a5b@infradead.org> In-Reply-To: <1236509237.5645.151.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> <1235216636.7025.1023.camel@andreas-laptop> <1236004353.10055.49.camel@andreas-laptop> <20090302082003.1bb7bdc5@infradead.org> <20090302102703.50aaf724@infradead.org> <1236192430.6785.111.camel@andreas-laptop> <20090305161837.6ba80cc1@infradead.org> <1236352543.6594.59.camel@andreas-laptop> <20090306074548.36ed2f9f@infradead.org> <1236509237.5645.151.camel@andreas-laptop> Organization: Intel X-Mailer: Claws Mail 3.7.0 (GTK+ 2.14.7; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2802 Lines: 76 On Sun, 08 Mar 2009 11:47:17 +0100 Andreas Robinson wrote: > > but I guess that is for Ubuntu to resolve. I don't see the machines > > I run (with Fedora) exhibit this same issue; while there are a > > bunch of modules, none of the ones that are expensive-and-useless > > in your charts are there. > > I think they will. Fast boot is one of the "essential" goals for > Jaunty and Karmic. > > Anyway, attached is a bootchart for a cleaned up kernel with the > important (AFAIK) drivers built in. thanks; very useful overview! > > >From this, I've found some tasks that I can set myself to. They would > obviously be the topic of other threads: > > * Make the nforce2 ethernet driver (init_nic) initialize itself > asynchronously, if possible. I looked at doing this generically and it is really hard. BUT.. one of the options is to move work from the init to the "ifconfig up" code... In addition, for 2.6.30, I have a patch pending to move sata init before the network init, which can help hide it some > > * New config option: Separate initramfs decompression and > file-system calls. Decompress as early as possible in a > separate thread. interesting idea! > > * Don't unpack initramfs twice. If CONFIG_BLK_DEV_RAM is > set, the kernel decompresses the ramdisk just to see if > it's a cpio archive or not, and then throws away the result. I actually have a patch for it stuck away somewhere; I thought it was sent upstream but apparently it was not. I'll dig it out and dust it off. Note: Having a smaller initrd (like Fedora does, they make the initrd only have the modules the specific machine needs) will save a bunch of time... what isn't there you don't have to decompress either. > > * See what can be done about pci_init(), if anything. > > If there's anything else regarding fastboot you think would make more > sense to work on first, please let me know. One thing to mention is that fastinit for sata... I only did AHCI (because all my machines have that). Your machine looks like it has something different than AHCI, so maybe the sata controller can use some work ;-) (a sata driver needs to opt into parallel scanning via a flag) SATA init tends to be one of the things that are fix time per drive; and so working on that first to at least ONLY get that is worth it, it's a huge chunk of time (more than half the total time in your bootchart) -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/