score: Add per-CPU profiling

Add per-CPU profiling stats API.  Implement the thread dispatch disable
level profiling.  The interrupt profiling must be implemented in CPU
port specific parts (mostly assembler code).  Add a support function
_Profiling_Outer_most_interrupt_entry_and_exit() for this purpose.

3 files changed, 216 insertions, 8 deletions

diff --git a/cpukit/score/include/rtems/score/percpu.h b/cpukit/score/include/rtems/score/percpu.h
index 067cb84a29..5ba463e812 100644
--- a/cpukit/score/include/rtems/score/percpu.h
+++ b/cpukit/score/include/rtems/score/percpu.h
@@ -155,6 +155,78 @@ typedef enum {
 #endif /* defined( RTEMS_SMP ) */
 
 /**
+ * @brief Per-CPU statistics.
+ */
+typedef struct {
+#if defined( RTEMS_PROFILING )
+  /**
+   * @brief The thread dispatch disabled begin instant in CPU counter ticks.
+   *
+   * This value is used to measure the time of disabled thread dispatching.
+   */
+  CPU_Counter_ticks thread_dispatch_disabled_instant;
+
+  /**
+   * @brief The maximum time of disabled thread dispatching in CPU counter
+   * ticks.
+   */
+  CPU_Counter_ticks max_thread_dispatch_disabled_time;
+
+  /**
+   * @brief The maximum time spent to process a single sequence of nested
+   * interrupts in CPU counter ticks.
+   *
+   * This is the time interval between the change of the interrupt nest level
+   * from zero to one and the change back from one to zero.
+   */
+  CPU_Counter_ticks max_interrupt_time;
+
+  /**
+   * @brief The maximum interrupt delay in CPU counter ticks if supported by
+   * the hardware.
+   */
+  CPU_Counter_ticks max_interrupt_delay;
+
+  /**
+   * @brief Count of times when the thread dispatch disable level changes from
+   * zero to one in thread context.
+   *
+   * This value may overflow.
+   */
+  uint64_t thread_dispatch_disabled_count;
+
+  /**
+   * @brief Total time of disabled thread dispatching in CPU counter ticks.
+   *
+   * The average time of disabled thread dispatching is the total time of
+   * disabled thread dispatching divided by the thread dispatch disabled
+   * count.
+   *
+   * This value may overflow.
+   */
+  uint64_t total_thread_dispatch_disabled_time;
+
+  /**
+   * @brief Count of times when the interrupt nest level changes from zero to
+   * one.
+   *
+   * This value may overflow.
+   */
+  uint64_t interrupt_count;
+
+  /**
+   * @brief Total time of interrupt processing in CPU counter ticks.
+   *
+   * The average time of interrupt processing is the total time of interrupt
+   * processing divided by the interrupt count.
+   *
+   * This value may overflow.
+   */
+  uint64_t total_interrupt_time;
+#endif /* defined( RTEMS_PROFILING ) */
+} Per_CPU_Stats;
+
+/**
  *  @brief Per CPU Core Structure
  *
  *  This structure is used to hold per core state information.
@@ -236,6 +308,8 @@ typedef struct {
      */
     Per_CPU_State state;
   #endif
+
+  Per_CPU_Stats Stats;
 } Per_CPU_Control;
 
 #if defined( RTEMS_SMP )
diff --git a/cpukit/score/include/rtems/score/profiling.h b/cpukit/score/include/rtems/score/profiling.h
new file mode 100644
index 0000000000..468c124450
--- /dev/null
+++ b/cpukit/score/include/rtems/score/profiling.h
@@ -0,0 +1,113 @@
+/**
+ * @file
+ *
+ * @ingroup ScoreProfiling
+ *
+ * @brief Profiling Support API
+ */
+
+/*
+ * Copyright (c) 2014 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#ifndef _RTEMS_SCORE_PROFILING
+#define _RTEMS_SCORE_PROFILING
+
+#include <rtems/score/percpu.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/**
+ * @defgroup ScoreProfiling Profiling Support
+ *
+ * @brief Profiling support.
+ *
+ * @{
+ */
+
+static inline void _Profiling_Thread_dispatch_disable(
+  Per_CPU_Control *per_cpu,
+  uint32_t previous_thread_dispatch_disable_level
+)
+{
+#if defined( RTEMS_PROFILING )
+  if ( previous_thread_dispatch_disable_level == 0 ) {
+    Per_CPU_Stats *stats = &per_cpu->Stats;
+
+    stats->thread_dispatch_disabled_instant = _CPU_Counter_read();
+    ++stats->thread_dispatch_disabled_count;
+  }
+#else
+  (void) per_cpu;
+  (void) previous_thread_dispatch_disable_level;
+#endif
+}
+
+static inline void _Profiling_Thread_dispatch_enable(
+  Per_CPU_Control *per_cpu,
+  uint32_t new_thread_dispatch_disable_level
+)
+{
+#if defined( RTEMS_PROFILING )
+  if ( new_thread_dispatch_disable_level == 0 ) {
+    Per_CPU_Stats *stats = &per_cpu->Stats;
+    CPU_Counter_ticks now = _CPU_Counter_read();
+    CPU_Counter_ticks delta = _CPU_Counter_difference(
+      now,
+      stats->thread_dispatch_disabled_instant
+    );
+
+    stats->total_thread_dispatch_disabled_time += delta;
+
+    if ( stats->max_thread_dispatch_disabled_time < delta ) {
+      stats->max_thread_dispatch_disabled_time = delta;
+    }
+  }
+#else
+  (void) per_cpu;
+  (void) new_thread_dispatch_disable_level;
+#endif
+}
+
+static inline void _Profiling_Update_max_interrupt_delay(
+  Per_CPU_Control *per_cpu,
+  CPU_Counter_ticks interrupt_delay
+)
+{
+#if defined( RTEMS_PROFILING )
+  Per_CPU_Stats *stats = &per_cpu->Stats;
+
+  if ( stats->max_interrupt_delay < interrupt_delay ) {
+    stats->max_interrupt_delay = interrupt_delay;
+  }
+#else
+  (void) per_cpu;
+  (void) interrupt_delay;
+#endif
+}
+
+void _Profiling_Outer_most_interrupt_entry_and_exit(
+  Per_CPU_Control *per_cpu,
+  CPU_Counter_ticks interrupt_entry_instant,
+  CPU_Counter_ticks interrupt_exit_instant
+);
+
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* _RTEMS_SCORE_PROFILING */
diff --git a/cpukit/score/include/rtems/score/threaddispatch.h b/cpukit/score/include/rtems/score/threaddispatch.h
index 5b25212de9..7e616d69f7 100644
--- a/cpukit/score/include/rtems/score/threaddispatch.h
+++ b/cpukit/score/include/rtems/score/threaddispatch.h
@@ -16,6 +16,7 @@
 
 #include <rtems/score/percpu.h>
 #include <rtems/score/smplock.h>
+#include <rtems/score/profiling.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -140,12 +141,22 @@ RTEMS_INLINE_ROUTINE void _Thread_Dispatch_initialization( void )
    */
   RTEMS_INLINE_ROUTINE uint32_t _Thread_Dispatch_increment_disable_level(void)
   {
-    uint32_t level = _Thread_Dispatch_disable_level;
+    uint32_t disable_level = _Thread_Dispatch_disable_level;
+#if defined( RTEMS_PROFILING )
+    ISR_Level level;
 
-    ++level;
-    _Thread_Dispatch_disable_level = level;
+    _ISR_Disable( level );
+    _Profiling_Thread_dispatch_disable( _Per_CPU_Get(), disable_level );
+#endif
+
+    ++disable_level;
+    _Thread_Dispatch_disable_level = disable_level;
+
+#if defined( RTEMS_PROFILING )
+    _ISR_Enable( level );
+#endif
 
-    return level;
+    return disable_level;
   }
 
   /**
@@ -155,12 +166,22 @@ RTEMS_INLINE_ROUTINE void _Thread_Dispatch_initialization( void )
    */
   RTEMS_INLINE_ROUTINE uint32_t _Thread_Dispatch_decrement_disable_level(void)
   {
-    uint32_t level = _Thread_Dispatch_disable_level;
+    uint32_t disable_level = _Thread_Dispatch_disable_level;
+#if defined( RTEMS_PROFILING )
+    ISR_Level level;
 
-    --level;
-    _Thread_Dispatch_disable_level = level;
+    _ISR_Disable( level );
+#endif
+
+    --disable_level;
+    _Thread_Dispatch_disable_level = disable_level;
+
+#if defined( RTEMS_PROFILING )
+    _Profiling_Thread_dispatch_enable( _Per_CPU_Get(), disable_level );
+    _ISR_Enable( level );
+#endif
 
-    return level;
+    return disable_level;
   }
 #endif /* RTEMS_SMP */