Re: 2.6.15-mm2

[Ingo Molnar <mingo@elte.hu>]

* Ingo Molnar <mingo@elte.hu> wrote:

> could you please also send me a SysRq-T (showTasks) output? [which 
> will also include all the stacktraces] (Please make sure you have 
> KALLSYMS_ALL enabled.)

a wild guess: could you also apply the debug patch below (and please 
keep CONFIG_DEBUG_MUTEXES enabled) - does it trigger anywhere during 
your bootup sequence? [it doesnt trigger here on an ext3 based bootup 
sequence]

	Ingo

--
check that mutexes are used in TASK_RUNNING state. Using a mutex within
some wait-for-event loop could result in wakeups getting lost.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

----

 kernel/mutex-debug.c |    5 +++++
 1 files changed, 5 insertions(+)

Index: linux/kernel/mutex-debug.c
===================================================================
--- linux.orig/kernel/mutex-debug.c
+++ linux/kernel/mutex-debug.c
@@ -385,6 +385,11 @@ void debug_mutex_init_waiter(struct mute
 	memset(waiter, 0x11, sizeof(*waiter));
 	waiter->magic = waiter;
 	INIT_LIST_HEAD(&waiter->list);
+	/*
+	 * Make sure mutexes are not acquired deep within some
+	 * waitqueue loop - wakeups could get lost:
+	 */
+	DEBUG_WARN_ON(current->state != TASK_RUNNING);
 }
 
 void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
-
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