Re: [PATCH v2 2/2] mce: don't try to wake thread before it exists.

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

* Sebastian Andrzej Siewior | 2015-03-06 22:01:27 [+0100]:

>We only miss a printk. The userland helper is not yet ready and we won't
>anyone one waiting on the wait queue. So it should be enough to simply
>check if the swait is ready.

So this should be enough and I fold this in you #1 patch. And now I see
that swork_queue() might be called from hardirq context so it needs irqs
off. I fix that one, too. But after that we should be good to go.

--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -1385,6 +1385,7 @@ static void __mce_notify_work(struct swo
 }
 
 #ifdef CONFIG_PREEMPT_RT_FULL
+static bool notify_work_ready __read_mostly;
 static struct swork_event notify_work;
 
 static int mce_notify_work_init(void)
@@ -1396,12 +1397,14 @@ static int mce_notify_work_init(void)
 		return err;
 
 	INIT_SWORK(&notify_work, __mce_notify_work);
+	notify_work_ready = true;
 	return 0;
 }
 
 static void mce_notify_work(void)
 {
-	swork_queue(&notify_work);
+	if (notify_work_ready)
+		swork_queue(&notify_work);
 }
 #else
 static void mce_notify_work(void)

Sebastian