Index: kernel/stop_machine.c
===================================================================
--- kernel/stop_machine.c	(revision 181)
+++ kernel/stop_machine.c	(working copy)
@@ -56,7 +56,7 @@
 		/* Yield in first stage: migration threads need to
 		 * help our sisters onto their CPUs. */
 		if (!prepared && !irqs_disabled)
-			yield();
+			rt_yield();
 		else
 			cpu_relax();
 	}
@@ -110,7 +110,7 @@
 
 	/* Wait for them all to come to life. */
 	while (atomic_read(&stopmachine_thread_ack) != stopmachine_num_threads)
-		yield();
+		rt_yield();
 
 	/* If some failed, kill them all. */
 	if (ret < 0) {
Index: kernel/sched.c
===================================================================
--- kernel/sched.c	(revision 181)
+++ kernel/sched.c	(working copy)
@@ -4288,7 +4288,7 @@
  * this is a shortcut for kernel-space yielding - it marks the
  * thread runnable and calls sys_sched_yield().
  */
-void __sched yield(void)
+static inline void __sched __yield(int rtok)
 {
 	static int once = 1;
 
@@ -4298,7 +4298,7 @@
 	 * us an idea about the scope of the problem, without spamming
 	 * the syslog:
 	 */
-	if (once && rt_task(current)) {
+	if (!rtok && once && rt_task(current)) {
 		once = 0;
 		printk(KERN_ERR "BUG: %s:%d RT task yield()-ing!\n",
 			current->comm, current->pid);
@@ -4308,7 +4308,18 @@
 	sys_sched_yield();
 }
 
+void __sched yield(void)
+{
+	__yield(0);
+}
+
+void __sched rt_yield(void)
+{
+	__yield(1);
+}
+
 EXPORT_SYMBOL(yield);
+EXPORT_SYMBOL(rt_yield);
 
 /*
  * This task is about to go to sleep on IO.  Increment rq->nr_iowait so
Index: include/linux/sched.h
===================================================================
--- include/linux/sched.h	(revision 181)
+++ include/linux/sched.h	(working copy)
@@ -1007,6 +1007,7 @@
 extern int mutex_getprio(task_t *p);
 
 void yield(void);
+void rt_yield(void);
 
 /*
  * The default (Linux) execution domain.