diff --git a/arch b/arch
index 790c6be472..bceb7b7852 160000
--- a/arch
+++ b/arch
@@ -1 +1 @@
-Subproject commit 790c6be472dd5c386723e5b54bef495300ad6d7d
+Subproject commit bceb7b7852a855d0de9afc4caeee801b4349db8e
diff --git a/include/sched.h b/include/sched.h
index 4fe16542d6..f3b675da72 100644
--- a/include/sched.h
+++ b/include/sched.h
@@ -145,13 +145,27 @@ int    sched_lockcount(void);
 
 void   sched_note_start(FAR struct tcb_s *tcb);
 void   sched_note_stop(FAR struct tcb_s *tcb);
-void   sched_note_switch(FAR struct tcb_s *pFromTcb,
-                         FAR struct tcb_s *pToTcb);
+void   sched_note_switch(FAR struct tcb_s *fromtcb,
+                         FAR struct tcb_s *totcb);
+
+#ifdef CONFIG_SCHED_INSTRUMENTATION_PREEMPTION
+void sched_note_premption(FAR struct tcb_s *tcb, bool locked);
+#else
+#  define sched_note_premption(t,l)
+#endif
+
+#ifdef CONFIG_SCHED_INSTRUMENTATION_CSECTION
+void sched_note_csection(FAR struct tcb_s *tcb, bool enter);
+#else
+#  define sched_note_csection(t,e)
+#endif
 
 #else
-# define sched_note_start(t)
-# define sched_note_stop(t)
-# define sched_note_switch(t1, t2)
+#  define sched_note_start(t)
+#  define sched_note_stop(t)
+#  define sched_note_switch(t1, t2)
+#  define sched_note_premption(t,l)
+#  define sched_note_csection(t,e)
 #endif /* CONFIG_SCHED_INSTRUMENTATION */
 
 #undef EXTERN
diff --git a/libc/stdio/lib_printf.c b/libc/stdio/lib_printf.c
index 7088452393..5f1096a3a2 100644
--- a/libc/stdio/lib_printf.c
+++ b/libc/stdio/lib_printf.c
@@ -33,10 +33,6 @@
  *
  ****************************************************************************/
 
-/****************************************************************************
- * Compilation Switches
- ****************************************************************************/
-
 /****************************************************************************
  * Included Files
  ****************************************************************************/
@@ -46,38 +42,6 @@
 
 #include "libc.h"
 
-/****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
-
-/****************************************************************************
- * Private Type Declarations
- ****************************************************************************/
-
-/****************************************************************************
- * Private Function Prototypes
- ****************************************************************************/
-
-/****************************************************************************
- * Public Function Prototypes
- ****************************************************************************/
-
-/****************************************************************************
- * Public Constant Data
- ****************************************************************************/
-
-/****************************************************************************
- * Public Data
- ****************************************************************************/
-
-/****************************************************************************
- * Private Constant Data
- ****************************************************************************/
-
-/****************************************************************************
- * Private Variables
- ****************************************************************************/
-
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -108,4 +72,3 @@ int printf(FAR const IPTR char *fmt, ...)
 
   return ret;
 }
-
diff --git a/sched/Kconfig b/sched/Kconfig
index c30b672b1d..574223fd67 100644
--- a/sched/Kconfig
+++ b/sched/Kconfig
@@ -601,10 +601,32 @@ config SCHED_INSTRUMENTATION
 		If enabled, then the board-specific logic must provide the following
 		functions (see include/sched.h):
 
-		void sched_note_start(FAR struct tcb_s *tcb);
-		void sched_note_stop(FAR struct tcb_s *tcb);
-		void sched_note_switch(FAR struct tcb_s *pFromTcb, FAR struct tcb_s *pToTcb);
+			void sched_note_start(FAR struct tcb_s *tcb);
+			void sched_note_stop(FAR struct tcb_s *tcb);
+			void sched_note_switch(FAR struct tcb_s *pFromTcb, FAR struct tcb_s *pToTcb);
 
+if SCHED_INSTRUMENTATION
+config SCHED_INSTRUMENTATION_PREEMPTION
+	bool "Preemption monitor hooks
+	default n
+	---help---
+		Enables additional hooks for changes to pre-emption state.  Board-
+		specific logic must provide this additional logic.
+
+			void sched_note_premption(FAR struct tcb_s *tcb, bool state);
+
+config SCHED_INSTRUMENTATION_CSECTION
+	bool "Critical section monitor hooks
+	default n
+	depends on SMP
+	---help---
+		Enables additional hooks for entry and exit from critical sections.
+		Interrupts are disabled while within a critical section.  Board-
+		specific logic must provide this additional logic.
+
+			void sched_note_csection(FAR struct tcb_s *tcb, bool state);
+
+endif # SCHED_INSTRUMENTATION
 endmenu # Performance Monitoring
 
 menu "Files and I/O"
diff --git a/sched/irq/irq_csection.c b/sched/irq/irq_csection.c
index 265236b464..34e77f3b1c 100644
--- a/sched/irq/irq_csection.c
+++ b/sched/irq/irq_csection.c
@@ -129,6 +129,12 @@ irqstate_t enter_critical_section(void)
 
       rtcb->irqcount = 1;
       g_cpu_irqset  |= (1 << this_cpu());
+
+#ifdef CONFIG_SCHED_INSTRUMENTATION_CSECTION
+      /* Note that we have entered the critical section */
+
+      sched_note_csection(rtcb, true);
+#endif
     }
 
   /* Then disable interrupts (they may already be disabled, be we need to
@@ -170,7 +176,12 @@ void leave_critical_section(irqstate_t flags)
         }
       else
         {
-          /* NO.. Release the spinlock to allow other access. */
+#ifdef CONFIG_SCHED_INSTRUMENTATION_CSECTION
+          /* No.. Note that we have entered the critical section */
+
+          sched_note_csection(rtcb, false);
+#endif
+          /* Release the spinlock to allow other access. */
 
           g_cpu_irqset  &= ~(1 << this_cpu());
           rtcb->irqcount = 0;
diff --git a/sched/sched/sched_lock.c b/sched/sched/sched_lock.c
index c524cdd8cc..025b0bf035 100644
--- a/sched/sched/sched_lock.c
+++ b/sched/sched/sched_lock.c
@@ -201,6 +201,17 @@ int sched_lock(void)
        */
 
       rtcb->lockcount++;
+
+#ifdef CONFIG_SCHED_INSTRUMENTATION_PREEMPTION
+      /* Check if we just acquired the lock */
+
+      if (rtcb->lockcount == 1)
+        {
+          /* Note that we have pre-emption locked */
+
+            sched_note_premption(rtcb, true);
+        }
+#endif
     }
 
   return OK;
diff --git a/sched/sched/sched_unlock.c b/sched/sched/sched_unlock.c
index 2c12f98f4d..35d9afd5fb 100644
--- a/sched/sched/sched_unlock.c
+++ b/sched/sched/sched_unlock.c
@@ -90,6 +90,13 @@ int sched_unlock(void)
 
       if (rtcb->lockcount <= 0)
         {
+#ifdef CONFIG_SCHED_INSTRUMENTATION_PREEMPTION
+          /* Note that we no longer have pre-emption */
+
+          sched_note_premption(rtcb, false);
+#endif
+          /* Set the lock count to zero */
+
           rtcb->lockcount = 0;
 
 #ifdef CONFIG_SMP