From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753105AbYIUWpt (ORCPT ); Sun, 21 Sep 2008 18:45:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752655AbYIUWpi (ORCPT ); Sun, 21 Sep 2008 18:45:38 -0400 Received: from casper.infradead.org ([85.118.1.10]:52936 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752819AbYIUWpi convert rfc822-to-8bit (ORCPT ); Sun, 21 Sep 2008 18:45:38 -0400 Date: Sun, 21 Sep 2008 15:45:41 -0700 From: Arjan van de Ven To: linux-kernel@vger.kernel.org Cc: neilb@suse.de, mingo@elte.hu, davej@redhat.com Subject: [PATCH] raid: make RAID autodetect default a KConfig option Message-ID: <20080921154541.371f2ebe@infradead.org> Organization: Intel X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.11; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT 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 >>From 812bf9a448d96375a3aec5c51764d74cace85abb Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sun, 21 Sep 2008 15:44:32 -0700 Subject: [PATCH] raid: make RAID autodetect default a KConfig option RAID autodetect has the side effect of requiring synchronisation of all device drivers, which can make the boot several seconds longer (I've measured 7 on one of my laptops).... even for systems that don't have RAID setup for the root filesystem (the only FS where this matters). This patch makes the default for autodetect a config option; either way the user can always override via the kernel command line. Signed-off-by: Arjan van de Ven --- drivers/md/Kconfig | 14 ++++++++++++++ init/do_mounts_md.c | 11 +++++++++-- 2 files changed, 23 insertions(+), 2 deletions(-) diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 07d92c1..8e72c91 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -30,6 +30,20 @@ config BLK_DEV_MD If unsure, say N. +config MD_AUTODETECT + bool "Autodetect RAID arrays during kernel boot" + depends on BLK_DEV_MD + default y + ---help--- + If you say Y here, then the kernel will try to autodetect raid + arrays as part of its boot process. + + If you don't use raid and say Y, this autodetection can cause + a several-second delay in the boot time due to various + synchronisation steps that are part of this step. + + If unsure, say Y. + config MD_LINEAR tristate "Linear (append) mode" depends on BLK_DEV_MD diff --git a/init/do_mounts_md.c b/init/do_mounts_md.c index c0dfd3c..48b3fad 100644 --- a/init/do_mounts_md.c +++ b/init/do_mounts_md.c @@ -12,7 +12,12 @@ * The code for that is here. */ -static int __initdata raid_noautodetect, raid_autopart; +#ifdef CONFIG_MD_AUTODETECT +static int __initdata raid_noautodetect; +#else +static int __initdata raid_noautodetect=1; +#endif +static int __initdata raid_autopart; static struct { int minor; @@ -252,6 +257,8 @@ static int __init raid_setup(char *str) if (!strncmp(str, "noautodetect", wlen)) raid_noautodetect = 1; + if (!strncmp(str, "autodetect", wlen)) + raid_noautodetect = 0; if (strncmp(str, "partitionable", wlen)==0) raid_autopart = 1; if (strncmp(str, "part", wlen)==0) @@ -288,7 +295,7 @@ void __init md_run_setup(void) create_dev("/dev/md0", MKDEV(MD_MAJOR, 0)); if (raid_noautodetect) - printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=noautodetect)\n"); + printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n"); else autodetect_raid(); md_setup_drive(); -- 1.5.5.1 -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org