[PATCH] fix jiffies clocksource inittime

In debugging a problem w/ the -rt tree, I noticed that on systems that mark
the tsc as unstable before it is registered, the TSC would still be
selected and used for a short period of time.  Digging in it looks to be a
result of the mix of the clocksource list changes and my clocksource
initialization changes.

With the -rt tree, using a bad TSC, even for a short period of time can
results in a hang at boot.  I was not able to reproduce this hang w/
mainline, but I'm not completely certain that someone won't trip on it.

This patch resolves the issue by initializing the jiffies clocksource
earlier so a bad TSC won't get selected just because nothing else is yet
registered.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index 3be8da8..4c256fd 100644 (file)
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -69,4 +69,4 @@ static int __init init_jiffies_clocksource(void)
        return clocksource_register(&clocksource_jiffies);
 }
 
-module_init(init_jiffies_clocksource);
+core_initcall(init_jiffies_clocksource);