Re: irda rmmod lockdep trace.

[Samuel Ortiz <samuel@sortiz.org>]

On Mon, Mar 12, 2007 at 04:49:21PM -0700, David Miller wrote:
> I would strongly caution against adding any run-time overhead just to
> cure a false lockdep warning.  Even adding a new function argument
> is too much IMHO.
> 
> Make the cost show up for lockdep only, perhaps by putting each
> hashbin lock into a seperate locking class?
Does that look better to you:

diff --git a/include/net/irda/irqueue.h b/include/net/irda/irqueue.h
index 335b0ac..67cb434 100644
--- a/include/net/irda/irqueue.h
+++ b/include/net/irda/irqueue.h
@@ -71,6 +71,7 @@ typedef struct hashbin_t {
 	int        hb_size;
 	spinlock_t hb_spinlock;		/* HB_LOCK - Can be used by the user */
 
+	struct lock_class_key hb_lock_key;
 	irda_queue_t* hb_queue[HASHBIN_SIZE] IRDA_ALIGN;
 
 	irda_queue_t* hb_current;
diff --git a/net/irda/irqueue.c b/net/irda/irqueue.c
index 9266233..c72ecee 100644
--- a/net/irda/irqueue.c
+++ b/net/irda/irqueue.c
@@ -370,6 +370,8 @@ hashbin_t *hashbin_new(int type)
 	/* Make sure all spinlock's are unlocked */
 	if ( hashbin->hb_type & HB_LOCK ) {
 		spin_lock_init(&hashbin->hb_spinlock);
+		lockdep_set_class(&hashbin->hb_spinlock,
+				  &hashbin->hb_lock_key);
 	}
 
 	return hashbin;