[PATCH] del_timer_sync(): add cpu_relax()

Relax the CPU in the del_timer_sync() busywait loop.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kernel/timer.c

@@ -374,6 +374,7 @@ int del_timer_sync(struct timer_list *timer)
 		int ret = try_to_del_timer_sync(timer);
 		if (ret >= 0)
 			return ret;
+		cpu_relax();
 	}
 }