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* [PATCH] raid: make RAID autodetect default a KConfig option
@ 2008-09-21 22:45 Arjan van de Ven
  2008-09-22  8:27 ` Ingo Molnar
  0 siblings, 1 reply; 6+ messages in thread
From: Arjan van de Ven @ 2008-09-21 22:45 UTC (permalink / raw)
  To: linux-kernel; +Cc: neilb, mingo, davej


>From 812bf9a448d96375a3aec5c51764d74cace85abb Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
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 <arjan@linux.intel.com>
---
 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

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH] raid: make RAID autodetect default a KConfig option
  2008-09-21 22:45 [PATCH] raid: make RAID autodetect default a KConfig option Arjan van de Ven
@ 2008-09-22  8:27 ` Ingo Molnar
  2008-09-23  3:45   ` Neil Brown
  0 siblings, 1 reply; 6+ messages in thread
From: Ingo Molnar @ 2008-09-22  8:27 UTC (permalink / raw)
  To: Arjan van de Ven, neilb; +Cc: linux-kernel, neilb, davej


* Arjan van de Ven <arjan@infradead.org> wrote:

> From 812bf9a448d96375a3aec5c51764d74cace85abb Mon Sep 17 00:00:00 2001
> From: Arjan van de Ven <arjan@linux.intel.com>
> 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.

Neil, if you agree with this patch, could you please send your Acked-by 
line? This patch depends on a clean-up in init/do_mounts_md.c that is in 
the fastboot tree so it would be logistically easier/better if we could 
queue this up towards upstream via tip/fastboot.

	Ingo

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] raid: make RAID autodetect default a KConfig option
  2008-09-22  8:27 ` Ingo Molnar
@ 2008-09-23  3:45   ` Neil Brown
  2008-09-23  3:58     ` Arjan van de Ven
  0 siblings, 1 reply; 6+ messages in thread
From: Neil Brown @ 2008-09-23  3:45 UTC (permalink / raw)
  To: Ingo Molnar; +Cc: Arjan van de Ven, linux-kernel, davej

On Monday September 22, mingo@elte.hu wrote:
> 
> * Arjan van de Ven <arjan@infradead.org> wrote:
> 
> > From 812bf9a448d96375a3aec5c51764d74cace85abb Mon Sep 17 00:00:00 2001
> > From: Arjan van de Ven <arjan@linux.intel.com>
> > 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.
> 
> Neil, if you agree with this patch, could you please send your Acked-by 
> line? This patch depends on a clean-up in init/do_mounts_md.c that is in 
> the fastboot tree so it would be logistically easier/better if we could 
> queue this up towards upstream via tip/fastboot.

Yes,
 Acked-by: NeilBrown <neilb@suse.de>

I'm not a big fan of autodetect in any case, and this patch seems to
cover all the bases I can think of.

Thanks,
NeilBrown

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] raid: make RAID autodetect default a KConfig option
  2008-09-23  3:45   ` Neil Brown
@ 2008-09-23  3:58     ` Arjan van de Ven
  2008-09-23  9:15       ` Ingo Molnar
  0 siblings, 1 reply; 6+ messages in thread
From: Arjan van de Ven @ 2008-09-23  3:58 UTC (permalink / raw)
  To: Neil Brown; +Cc: Ingo Molnar, linux-kernel, davej

On Tue, 23 Sep 2008 13:45:19 +1000
Neil Brown <neilb@suse.de> wrote:

> On Monday September 22, mingo@elte.hu wrote:
> > 
> > * Arjan van de Ven <arjan@infradead.org> wrote:
> > 
> > > From 812bf9a448d96375a3aec5c51764d74cace85abb Mon Sep 17 00:00:00
> > > 2001 From: Arjan van de Ven <arjan@linux.intel.com>
> > > 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.
> > 
> > Neil, if you agree with this patch, could you please send your
> > Acked-by line? This patch depends on a clean-up in
> > init/do_mounts_md.c that is in the fastboot tree so it would be
> > logistically easier/better if we could queue this up towards
> > upstream via tip/fastboot.
> 
> Yes,
>  Acked-by: NeilBrown <neilb@suse.de>
> 
> I'm not a big fan of autodetect in any case, and this patch seems to
> cover all the bases I can think of.
> 

thanks
pushed to
git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-fastboot.git
master

Ingo, please pull


-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] raid: make RAID autodetect default a KConfig option
  2008-09-23  3:58     ` Arjan van de Ven
@ 2008-09-23  9:15       ` Ingo Molnar
  0 siblings, 0 replies; 6+ messages in thread
From: Ingo Molnar @ 2008-09-23  9:15 UTC (permalink / raw)
  To: Arjan van de Ven; +Cc: Neil Brown, linux-kernel, davej


* Arjan van de Ven <arjan@infradead.org> wrote:

> On Tue, 23 Sep 2008 13:45:19 +1000
> Neil Brown <neilb@suse.de> wrote:
> 
> > On Monday September 22, mingo@elte.hu wrote:
> > > 
> > > * Arjan van de Ven <arjan@infradead.org> wrote:
> > > 
> > > > From 812bf9a448d96375a3aec5c51764d74cace85abb Mon Sep 17 00:00:00
> > > > 2001 From: Arjan van de Ven <arjan@linux.intel.com>
> > > > 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.
> > > 
> > > Neil, if you agree with this patch, could you please send your
> > > Acked-by line? This patch depends on a clean-up in
> > > init/do_mounts_md.c that is in the fastboot tree so it would be
> > > logistically easier/better if we could queue this up towards
> > > upstream via tip/fastboot.
> > 
> > Yes,
> >  Acked-by: NeilBrown <neilb@suse.de>
> > 
> > I'm not a big fan of autodetect in any case, and this patch seems to
> > cover all the bases I can think of.
> > 
> 
> thanks
> pushed to
> git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-fastboot.git
> master
> 
> Ingo, please pull

pulled the commit below into tip/fastboot, thanks Arjan and Neil!

	Ingo

---------------->
>From da827bea62d62cabfe913e05fc05879faa614af8 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
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 <arjan@linux.intel.com>
Acked-by: NeilBrown <neilb@suse.de>
---
 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();

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH] raid: make RAID autodetect default a KConfig option
@ 2008-09-23 15:37 Alan Jenkins
  0 siblings, 0 replies; 6+ messages in thread
From: Alan Jenkins @ 2008-09-23 15:37 UTC (permalink / raw)
  To: Arjan van de Ven; +Cc: neilb, linux-kernel

I noticed this Configure option is present even if BLK_DEV_MD=m.  In
this case the option does nothing, which is inconsistent with the help
text and generally odd :-).

Would you change it?

------

Hide RAID autodetect option if MD is compiled as a module.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>

diff --git a/drivers/md/Configure b/drivers/md/Configure
index 8e72c91..2281b50 100644
--- a/drivers/md/Configure
+++ b/drivers/md/Configure
@@ -32,7 +32,7 @@ config BLK_DEV_MD
 
 config MD_AUTODETECT
 	bool "Autodetect RAID arrays during kernel boot"
-	depends on BLK_DEV_MD
+	depends on BLK_DEV_MD=y
 	default y
 	---help---
 	  If you say Y here, then the kernel will try to autodetect raid


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2008-09-23 15:38 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-09-21 22:45 [PATCH] raid: make RAID autodetect default a KConfig option Arjan van de Ven
2008-09-22  8:27 ` Ingo Molnar
2008-09-23  3:45   ` Neil Brown
2008-09-23  3:58     ` Arjan van de Ven
2008-09-23  9:15       ` Ingo Molnar
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2008-09-23 15:37 Alan Jenkins

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