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From: john stultz <johnstul@us.ibm.com>
To: Andrew Morton <akpm@osdl.org>
Cc: lkml <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
	Andi Kleen <ak@muc.de>
Subject: [PATCH -mm] fix jiffies clocksource inittime
Date: Wed, 04 Apr 2007 12:50:15 -0700	[thread overview]
Message-ID: <1175716216.17711.59.camel@localhost> (raw)

Andrew,
	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.

thanks
-john

Signed-off-by: John Stultz <johnstul@us.ibm.com>

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



             reply	other threads:[~2007-04-04 19:50 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-04 19:50 john stultz [this message]
2007-04-04 20:43 ` [PATCH -mm] fix jiffies clocksource inittime Andrew Morton
2007-04-04 20:46   ` Thomas Gleixner
2007-04-04 20:53   ` john stultz
2007-04-04 21:04     ` Andrew Morton
2007-04-04 21:23   ` Ingo Molnar
2007-04-04 21:32     ` Andrew Morton

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