diff --git a/arch/sim/src/Makefile b/arch/sim/src/Makefile
index a9e9094266..dc5aceaeff 100644
--- a/arch/sim/src/Makefile
+++ b/arch/sim/src/Makefile
@@ -73,6 +73,10 @@ ifeq ($(CONFIG_SMP),y)
   HOSTSRCS += up_simsmp.c
 endif
 
+ifeq ($(CONFIG_SCHED_INSTRUMENTATION),y)
+  CSRCS += up_schednote.c
+endif
+
 ifeq ($(CONFIG_DEV_CONSOLE),y)
   CSRCS += up_uartwait.c
   HOSTSRCS += up_simuart.c
diff --git a/arch/sim/src/up_schednote.c b/arch/sim/src/up_schednote.c
new file mode 100644
index 0000000000..c3b54deb53
--- /dev/null
+++ b/arch/sim/src/up_schednote.c
@@ -0,0 +1,137 @@
+/****************************************************************************
+ * arch/sim/src/up_schednote.c
+ *
+ *   Copyright (C) 2016 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <syslog.h>
+#include <nuttx/sched.h>
+
+#ifdef CONFIG_SCHED_INSTRUMENTATION
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: sched_note_start, sched_note_stop, sched_note_switch
+ *
+ * Description:
+ *   Create the pthread-specific data key and set the indication of CPU0
+ *   the the main thread.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   An integer index in the range of 0 through (CONFIG_SMP_NCPUS-1) that
+ *   corresponds to the currently executing CPU.
+ *
+ ****************************************************************************/
+
+void sched_note_start(FAR struct tcb_s *tcb)
+{
+#ifdef CONFIG_SMP
+#if CONFIG_TASK_NAME_SIZE > 0
+  lowsyslog(LOG_INFO, "CPU%d: Start %s, TCB@%p, state=%d\n",
+            tcb->cpu, tcb->name, tcb, tcb->task_state);
+#else  
+  lowsyslog(LOG_INFO, "CPU%d: Start TCB@%p, state=%d\n"
+            tcb->cpu, tcb, tcb->task_state);
+#endif
+#else
+#if CONFIG_TASK_NAME_SIZE > 0
+  lowsyslog(LOG_INFO, "Start %s, TCB@%p, state=%d\n",
+            tcb->name, tcb, tcb->task_state);
+#else  
+  lowsyslog(LOG_INFO, "Start TCB@%p, state=%d\n",
+            tcb, tcb->task_state);
+#endif
+#endif
+}
+
+void sched_note_stop(FAR struct tcb_s *tcb)
+{
+#ifdef CONFIG_SMP
+#if CONFIG_TASK_NAME_SIZE > 0
+  lowsyslog(LOG_INFO, "CPU%d: Stop %s, TCB@%p, state=%d\n",
+            tcb->cpu, tcb->name, tcb, tcb->task_state);
+#else  
+  lowsyslog(LOG_INFO, "CPU%d: Stop TCB@%p, state=%d\n",
+            tcb->cpu, tcb, tcb->task_state);
+#endif
+#else
+#if CONFIG_TASK_NAME_SIZE > 0
+  lowsyslog(LOG_INFO, "Stop %s, TCB@%p, state=%d\n",
+            tcb->name, tcb, tcb->task_state);
+#else  
+  lowsyslog(LOG_INFO, "Stop TCB@%p, state=%d\n",
+            tcb, tcb->task_state);
+#endif
+#endif
+}
+
+void sched_note_switch(FAR struct tcb_s *from, FAR struct tcb_s *to)
+{
+#ifdef CONFIG_SMP
+#if CONFIG_TASK_NAME_SIZE > 0
+  lowsyslog(LOG_INFO, "CPU%d: Suspend %s, TCB@%p, state=%d\n",
+            from->cpu, from->name, from, from->task_state);
+  lowsyslog(LOG_INFO, "CPU%d: Resume %s, TCB@%p, state=%d\n",
+            to->cpu, to->name, to, to->task_state);
+#else  
+  lowsyslog(LOG_INFO, "CPU%d: Stop TCB@%p, state=%d\n",
+            from->cpu, from, from->task_state);
+  lowsyslog(LOG_INFO, "CPU%d: Resume TCB@%p, state=%d\n",
+            to->cpu, to, to->task_state);
+#endif
+#else
+#if CONFIG_TASK_NAME_SIZE > 0
+  lowsyslog(LOG_INFO, "Stop %s, TCB@%p, state=%d\n",
+            from->name, from, from->task_state);
+  lowsyslog(LOG_INFO, "Resume %s, TCB@%p\, state=%dn",
+            to->name, to, to->task_state);
+#else  
+  lowsyslog(LOG_INFO, "Stop TCB@%p, state=%d\n",
+            from, from->task_state);
+  lowsyslog(LOG_INFO, "Resume TCB@%p, state=%d\n",
+            to, to->task_state);
+#endif
+#endif
+}
+
+#endif /* CONFIG_SCHED_INSTRUMENTATION */