[PATCH] remove io context refcounting debug

This removes the remains of some debugging stuff which was never really
enabled properly - it never reported memory leaks.  Its not useful for
anyone but me. 

A proper solution involves counting all requests in flight and all
threads but we'll probably put that just into mm.

drivers/block/as-iosched.c

@@ -173,13 +173,10 @@ static kmem_cache_t *arq_pool;
 /*
  * IO Context helper functions
  */
-/* Debug */
-static atomic_t nr_as_io_requests = ATOMIC_INIT(0);
 
 /* Called to deallocate the as_io_context */
 static void free_as_io_context(struct as_io_context *aic)
 {
-	atomic_dec(&nr_as_io_requests);
 	kfree(aic);
 }
 
@@ -195,7 +192,6 @@ static struct as_io_context *alloc_as_io_context(void)
 
 	ret = kmalloc(sizeof(*ret), GFP_ATOMIC);
 	if (ret) {
-		atomic_inc(&nr_as_io_requests);
 		ret->dtor = free_as_io_context;
 		ret->exit = exit_as_io_context;
 		ret->state = 1 << AS_TASK_RUNNING;

drivers/block/ll_rw_blk.c

@@ -2576,8 +2576,6 @@ int __init blk_dev_init(void)
 	return 0;
 }
 
-static atomic_t nr_io_contexts = ATOMIC_INIT(0);
-
 /*
  * IO Context helper functions
  */
@@ -2592,7 +2590,6 @@ void put_io_context(struct io_context *ioc)
 		if (ioc->aic && ioc->aic->dtor)
 			ioc->aic->dtor(ioc->aic);
 		kfree(ioc);
-		atomic_dec(&nr_io_contexts);
 	}
 }
 
@@ -2633,7 +2630,6 @@ struct io_context *get_io_context(int gfp_flags)
 	if (ret == NULL) {
 		ret = kmalloc(sizeof(*ret), GFP_ATOMIC);
 		if (ret) {
-			atomic_inc(&nr_io_contexts);
 			atomic_set(&ret->refcount, 1);
 			ret->pid = tsk->pid;
 			ret->last_waited = jiffies; /* doesn't matter... */