diff --git a/sys/kern/kern_clock.c b/sys/kern/kern_clock.c
index ab2f12957ec1..4ac211df140c 100644
--- a/sys/kern/kern_clock.c
+++ b/sys/kern/kern_clock.c
@@ -418,6 +418,8 @@ statclock(frame)
 				cp_time[CP_IDLE]++;
 		}
 	}
+	CTR4(KTR_SCHED, "statclock: %p(%s) prio %d stathz %d",
+	    td, td->td_proc->p_comm, td->td_priority, (stathz)?stathz:hz);
 
 	sched_clock(td);
 
diff --git a/sys/kern/kern_switch.c b/sys/kern/kern_switch.c
index 3177f72edddb..c59af8b53b5e 100644
--- a/sys/kern/kern_switch.c
+++ b/sys/kern/kern_switch.c
@@ -456,6 +456,9 @@ setrunqueue(struct thread *td, int flags)
 
 	CTR3(KTR_RUNQ, "setrunqueue: td:%p kg:%p pid:%d",
 	    td, td->td_ksegrp, td->td_proc->p_pid);
+	CTR5(KTR_SCHED, "setrunqueue: %p(%s) prio %d by %p(%s)",
+            td, td->td_proc->p_comm, td->td_priority, curthread,
+            curthread->td_proc->p_comm);
 	mtx_assert(&sched_lock, MA_OWNED);
 	KASSERT((td->td_inhibitors == 0),
 			("setrunqueue: trying to run inhibitted thread"));
diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index b6968bf33d36..bd28c1de0b76 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -340,7 +340,24 @@ mi_switch(int flags, struct thread *newtd)
 	    (void *)td, td->td_sched, (long)p->p_pid, p->p_comm);
 	if ((flags & SW_VOL) && (td->td_proc->p_flag & P_SA))
 		newtd = thread_switchout(td, flags, newtd);
+#if (KTR_COMPILE & KTR_SCHED) != 0
+	if (td == PCPU_GET(idlethread))
+		CTR3(KTR_SCHED, "mi_switch: %p(%s) prio %d idle",
+		    td, td->td_proc->p_comm, td->td_priority);
+	else if (newtd != NULL)
+		CTR5(KTR_SCHED,
+		    "mi_switch: %p(%s) prio %d preempted by %p(%s)",
+		    td, td->td_proc->p_comm, td->td_priority, newtd,
+		    newtd->td_proc->p_comm);
+	else
+		CTR6(KTR_SCHED,
+		    "mi_switch: %p(%s) prio %d inhibit %d wmesg %s lock %s",
+		    td, td->td_proc->p_comm, td->td_priority,
+		    td->td_inhibitors, td->td_wmesg, td->td_lockname);
+#endif
 	sched_switch(td, newtd, flags);
+	CTR3(KTR_SCHED, "mi_switch: running %p(%s) prio %d",
+	    td, td->td_proc->p_comm, td->td_priority);
 
 	CTR4(KTR_PROC, "mi_switch: new thread %p (kse %p, pid %ld, %s)",
 	    (void *)td, td->td_sched, (long)p->p_pid, p->p_comm);