[Patch] rcupdate: remove dead code

[Amerigo Wang <amwang@redhat.com>]

DEBUG_OBJECTS_RCU_HEAD depends on PREEMPT, so #ifndef CONFIG_PREEMPT
is totally useless in kernel/rcupdate.c.

Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>


---
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index a23a57a..afd21d1 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -215,10 +215,6 @@ static int rcuhead_fixup_free(void *addr, enum debug_obj_state state)
 		 * If we detect that we are nested in a RCU read-side critical
 		 * section, we should simply fail, otherwise we would deadlock.
 		 */
-#ifndef CONFIG_PREEMPT
-		WARN_ON(1);
-		return 0;
-#else
 		if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
 		    irqs_disabled()) {
 			WARN_ON(1);
@@ -229,7 +225,6 @@ static int rcuhead_fixup_free(void *addr, enum debug_obj_state state)
 		rcu_barrier_bh();
 		debug_object_free(head, &rcuhead_debug_descr);
 		return 1;
-#endif
 	default:
 		return 0;
 	}