Allow softlockup to be runtime disabled.

Allow softlockup to be runtime disabled.

[Dave Jones]

It's useful sometimes to disable the softlockup checker at boottime.
Especially if it triggers during a distro install.

Signed-off-by: Dave Jones <davej@redhat.com>

--- linux-2.6/init/main.c~	2006-03-05 00:45:51.000000000 -0500
+++ linux-2.6/init/main.c	2006-03-05 00:49:41.000000000 -0500
@@ -732,6 +732,15 @@ static void __init do_basic_setup(void)
 	do_initcalls();
 }
 
+static int __initdata nosoftlockup;
+
+static int __init nosoftlockup_setup(char *str)
+{
+	nosoftlockup = 1;
+	return 1;
+}
+__setup("nosoftlockup", nosoftlockup_setup);
+
 static void __init do_pre_smp_initcalls(void)
 {
 	extern int spawn_ksoftirqd(void);
@@ -649,7 +657,8 @@ static void do_pre_smp_initcalls(void)
 	migration_init();
 #endif
 	spawn_ksoftirqd();
-	spawn_softlockup_task();
+	if (!nosoftlockup)
+		spawn_softlockup_task();
 }
 
 static void run_init_process(char *init_filename)

-- 
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Re: Allow softlockup to be runtime disabled.

[Peter Zijlstra]

On Mon, 2007-06-11 at 23:13 -0400, Dave Jones wrote:
> It's useful sometimes to disable the softlockup checker at boottime.
> Especially if it triggers during a distro install.

Should we not rather fix these occurrences?

Re: Allow softlockup to be runtime disabled.

[Dave Jones]

On Tue, Jun 12, 2007 at 01:49:45PM +0200, Peter Zijlstra wrote:
 > On Mon, 2007-06-11 at 23:13 -0400, Dave Jones wrote:
 > > It's useful sometimes to disable the softlockup checker at boottime.
 > > Especially if it triggers during a distro install.
 > 
 > Should we not rather fix these occurrences?

We do, but we can't easily fix the kernel that ends up on
install media.  It's easier to tell a user
"boot with nosoftlockup, then update your kernel after its installed"
than it is to guide them through reconstructing an ISO with
an updated kernel.

	Dave

-- 
http://www.codemonkey.org.uk