Re: Realtime Preemption, 2.6.12, Beginners Guide?

[Ingo Molnar <mingo@elte.hu>]

* Alistair John Strachan <s0348365@sms.ed.ac.uk> wrote:

> Interesting. They're both exactly 10001 jiffies apart.
>
> BUG: soft lockup detected on CPU#0! -283805--293806

yes, that's the 10 second softlockup timeout.

does the patch below help? We initialized the timestamps to 0, but with 
jiffies starting out negative, that means a ~5 minutes gap until we 
first reach a value of 0. That would explain the messages. The only 
thing it doesnt explain, why did this only trigger on your box?

	Ingo

Index: linux/kernel/softlockup.c
===================================================================
--- linux.orig/kernel/softlockup.c
+++ linux/kernel/softlockup.c
@@ -16,9 +16,9 @@
 
 static DEFINE_RAW_SPINLOCK(print_lock);
 
-static DEFINE_PER_CPU(unsigned long, timeout) = 0;
-static DEFINE_PER_CPU(unsigned long, timestamp) = 0;
-static DEFINE_PER_CPU(unsigned long, print_timestamp) = 0;
+static DEFINE_PER_CPU(unsigned long, timeout) = INITIAL_JIFFIES;
+static DEFINE_PER_CPU(unsigned long, timestamp) = INITIAL_JIFFIES;
+static DEFINE_PER_CPU(unsigned long, print_timestamp) = INITIAL_JIFFIES;
 static DEFINE_PER_CPU(struct task_struct *, watchdog_task);
 
 static int did_panic = 0;
-
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