1 files changed, 6 insertions, 3 deletions

diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index ce6adb5e091b..344719d273cc 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -120,6 +120,10 @@ roundrobin_interval(void)
 
 /*
  * Force switch among equal priority processes every 100ms.
+ * We don't actually need to force a context switch of the current process.
+ * The act of firing the event triggers a context switch to softclock() and
+ * then switching back out again which is equivalent to a preemption, thus
+ * no further work is needed on the local CPU.
  */
 /* ARGSUSED */
 static void
@@ -127,12 +131,11 @@ roundrobin(arg)
 	void *arg;
 {
 
-	mtx_lock_spin(&sched_lock);
-	need_resched(curproc);
 #ifdef SMP
+	mtx_lock_spin(&sched_lock);
 	forward_roundrobin();
-#endif
 	mtx_unlock_spin(&sched_lock);
+#endif
 
 	callout_reset(&roundrobin_callout, sched_quantum, roundrobin, NULL);
 }