sched/note: Move the circle buffer code to driver

so the format code can be shared by different transport

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

boards/arm/cxd56xx/spresense/configs/smp/defconfig

@@ -26,6 +26,7 @@ CONFIG_CXD56_SPI5=y
 CONFIG_CXD56_SPI=y
 CONFIG_DEBUG_FULLOPT=y
 CONFIG_DEBUG_SYMBOLS=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_EXAMPLES_HELLO=y
 CONFIG_FS_PROCFS=y
 CONFIG_FS_PROCFS_REGISTER=y
@@ -45,7 +46,6 @@ CONFIG_RR_INTERVAL=200
 CONFIG_RTC=y
 CONFIG_RTC_DRIVER=y
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SDCLONE_DISABLE=y
 CONFIG_SMP=y
 CONFIG_SMP_NCPUS=2

boards/arm/imx6/sabre-6quad/configs/smp/defconfig

@@ -23,6 +23,7 @@ CONFIG_BUILTIN=y
 CONFIG_DEBUG_FULLOPT=y
 CONFIG_DEBUG_SYMBOLS=y
 CONFIG_DEV_ZERO=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_EXAMPLES_HELLO=y
 CONFIG_FS_PROCFS=y
 CONFIG_HAVE_CXX=y
@@ -49,7 +50,6 @@ CONFIG_RR_INTERVAL=200
 CONFIG_SCHED_HPWORK=y
 CONFIG_SCHED_HPWORKPRIORITY=192
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SMP=y
 CONFIG_SPINLOCK_IRQ=y
 CONFIG_START_MONTH=3

boards/arm/lc823450/lc823450-xgevk/configs/bt/defconfig

@@ -36,6 +36,7 @@ CONFIG_DEBUG_SYMBOLS=y
 CONFIG_DEV_ZERO=y
 CONFIG_DISABLE_POSIX_TIMERS=y
 CONFIG_DRIVERS_AUDIO=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_DVFS=y
 CONFIG_EXAMPLES_HELLO=y
 CONFIG_EXAMPLES_I2SLOOP=y
@@ -146,7 +147,6 @@ CONFIG_SCHED_HAVE_PARENT=y
 CONFIG_SCHED_HPWORK=y
 CONFIG_SCHED_HPWORKPRIORITY=192
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SCHED_INSTRUMENTATION_PREEMPTION=y
 CONFIG_SCHED_LPWORK=y
 CONFIG_SCHED_LPWORKPRIORITY=60

boards/arm/lc823450/lc823450-xgevk/configs/elf/defconfig

@@ -22,6 +22,7 @@ CONFIG_DEBUG_FULLOPT=y
 CONFIG_DEBUG_SYMBOLS=y
 CONFIG_DEV_ZERO=y
 CONFIG_DISABLE_POSIX_TIMERS=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_ELF=y
 CONFIG_EXAMPLES_ELF=y
 CONFIG_FS_PROCFS=y
@@ -54,7 +55,6 @@ CONFIG_SCHED_ATEXIT=y
 CONFIG_SCHED_CHILD_STATUS=y
 CONFIG_SCHED_HAVE_PARENT=y
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SCHED_ONEXIT=y
 CONFIG_SCHED_ONEXIT_MAX=32
 CONFIG_SCHED_STARTHOOK=y

boards/arm/lc823450/lc823450-xgevk/configs/ipl2/defconfig

@@ -21,6 +21,7 @@ CONFIG_DEBUG_SYMBOLS=y
 CONFIG_DEV_ZERO=y
 CONFIG_DISABLE_MQUEUE=y
 CONFIG_DISABLE_POSIX_TIMERS=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_FAT_LCNAMES=y
 CONFIG_FAT_LFN=y
 CONFIG_FS_FAT=y
@@ -54,7 +55,6 @@ CONFIG_SCHED_ATEXIT=y
 CONFIG_SCHED_CHILD_STATUS=y
 CONFIG_SCHED_HAVE_PARENT=y
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SCHED_ONEXIT=y
 CONFIG_SCHED_ONEXIT_MAX=32
 CONFIG_SCHED_STARTHOOK=y

boards/arm/lc823450/lc823450-xgevk/configs/knsh/defconfig

@@ -29,6 +29,7 @@ CONFIG_DEBUG_FULLOPT=y
 CONFIG_DEBUG_SYMBOLS=y
 CONFIG_DEV_ZERO=y
 CONFIG_DISABLE_POSIX_TIMERS=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_FS_PROCFS=y
 CONFIG_HRT_TIMER=y
 CONFIG_I2C=y
@@ -99,7 +100,6 @@ CONFIG_SCHED_ATEXIT=y
 CONFIG_SCHED_CHILD_STATUS=y
 CONFIG_SCHED_HAVE_PARENT=y
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SCHED_ONEXIT=y
 CONFIG_SCHED_ONEXIT_MAX=32
 CONFIG_SCHED_STARTHOOK=y

boards/arm/lc823450/lc823450-xgevk/configs/krndis/defconfig

@@ -37,6 +37,7 @@ CONFIG_DEV_URANDOM=y
 CONFIG_DEV_ZERO=y
 CONFIG_DISABLE_POSIX_TIMERS=y
 CONFIG_DRIVERS_AUDIO=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_DVFS=y
 CONFIG_ELF=y
 CONFIG_EXAMPLES_HELLO=m
@@ -154,7 +155,6 @@ CONFIG_SCHED_HAVE_PARENT=y
 CONFIG_SCHED_HPWORK=y
 CONFIG_SCHED_HPWORKPRIORITY=192
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SCHED_INSTRUMENTATION_PREEMPTION=y
 CONFIG_SCHED_LPWORK=y
 CONFIG_SCHED_LPWORKPRIORITY=60

boards/arm/lc823450/lc823450-xgevk/configs/nsh/defconfig

@@ -28,6 +28,7 @@ CONFIG_DEBUG_FULLOPT=y
 CONFIG_DEBUG_SYMBOLS=y
 CONFIG_DEV_ZERO=y
 CONFIG_DISABLE_POSIX_TIMERS=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_EXAMPLES_ADC=y
 CONFIG_EXAMPLES_ADC_GROUPSIZE=6
 CONFIG_EXAMPLES_ADC_SWTRIG=y
@@ -104,7 +105,6 @@ CONFIG_SCHED_ATEXIT=y
 CONFIG_SCHED_CHILD_STATUS=y
 CONFIG_SCHED_HAVE_PARENT=y
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SCHED_ONEXIT=y
 CONFIG_SCHED_ONEXIT_MAX=32
 CONFIG_SCHED_STARTHOOK=y

boards/arm/lc823450/lc823450-xgevk/configs/posix_spawn/defconfig

@@ -21,6 +21,7 @@ CONFIG_DEBUG_FULLOPT=y
 CONFIG_DEBUG_SYMBOLS=y
 CONFIG_DEV_ZERO=y
 CONFIG_DISABLE_POSIX_TIMERS=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_ELF=y
 CONFIG_EXAMPLES_POSIXSPAWN=y
 CONFIG_FS_PROCFS=y
@@ -53,7 +54,6 @@ CONFIG_SCHED_ATEXIT=y
 CONFIG_SCHED_CHILD_STATUS=y
 CONFIG_SCHED_HAVE_PARENT=y
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SCHED_ONEXIT=y
 CONFIG_SCHED_ONEXIT_MAX=32
 CONFIG_SCHED_STARTHOOK=y

boards/arm/lc823450/lc823450-xgevk/configs/rndis/defconfig

@@ -35,6 +35,7 @@ CONFIG_DEBUG_SYMBOLS=y
 CONFIG_DEV_ZERO=y
 CONFIG_DISABLE_POSIX_TIMERS=y
 CONFIG_DRIVERS_AUDIO=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_DVFS=y
 CONFIG_ELF=y
 CONFIG_EXAMPLES_HELLO=m
@@ -154,7 +155,6 @@ CONFIG_SCHED_HAVE_PARENT=y
 CONFIG_SCHED_HPWORK=y
 CONFIG_SCHED_HPWORKPRIORITY=192
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SCHED_INSTRUMENTATION_PREEMPTION=y
 CONFIG_SCHED_LPWORK=y
 CONFIG_SCHED_LPWORKPRIORITY=60

boards/arm/lc823450/lc823450-xgevk/configs/usb/defconfig

@@ -27,6 +27,7 @@ CONFIG_DEBUG_FULLOPT=y
 CONFIG_DEBUG_SYMBOLS=y
 CONFIG_DEV_ZERO=y
 CONFIG_DISABLE_POSIX_TIMERS=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_ELF=y
 CONFIG_ELF_BUFFERSIZE=512
 CONFIG_EXAMPLES_ADC=y
@@ -107,7 +108,6 @@ CONFIG_SCHED_ATEXIT=y
 CONFIG_SCHED_CHILD_STATUS=y
 CONFIG_SCHED_HAVE_PARENT=y
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SCHED_ONEXIT=y
 CONFIG_SCHED_ONEXIT_MAX=32
 CONFIG_SCHED_STARTHOOK=y

boards/arm/stm32f7/stm32f746-ws/configs/nsh/defconfig

@@ -31,6 +31,7 @@ CONFIG_C99_BOOL8=y
 CONFIG_CDCACM=y
 CONFIG_CDCACM_EPINTIN_HSSIZE=512
 CONFIG_DEBUG_SYMBOLS=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_FAT_DMAMEMORY=y
 CONFIG_FAT_LCNAMES=y
 CONFIG_FAT_LFN=y
@@ -69,7 +70,6 @@ CONFIG_SCHED_HPWORK=y
 CONFIG_SCHED_HPWORKPRIORITY=192
 CONFIG_SCHED_HPWORKSTACKSIZE=1800
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SCHED_LPWORK=y
 CONFIG_SCHED_LPWORKSTACKSIZE=1800
 CONFIG_SCHED_NOTE_BUFSIZE=512

boards/risc-v/k210/maix-bit/configs/smp/defconfig

@@ -21,6 +21,7 @@ CONFIG_BUILTIN=y
 CONFIG_DEBUG_FULLOPT=y
 CONFIG_DEBUG_SYMBOLS=y
 CONFIG_DEV_ZERO=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_EXAMPLES_HELLO=y
 CONFIG_FS_PROCFS=y
 CONFIG_FS_PROCFS_REGISTER=y
@@ -48,7 +49,6 @@ CONFIG_RAW_BINARY=y
 CONFIG_READLINE_CMD_HISTORY=y
 CONFIG_RR_INTERVAL=200
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SMP=y
 CONFIG_SMP_NCPUS=2
 CONFIG_SPINLOCK_IRQ=y

boards/xtensa/esp32/esp32-core/configs/smp/defconfig

@@ -20,6 +20,7 @@ CONFIG_BUILTIN=y
 CONFIG_DEBUG_FEATURES=y
 CONFIG_DEBUG_FULLOPT=y
 CONFIG_DEBUG_SYMBOLS=y
+CONFIG_DRIVER_NOTE=y
 CONFIG_ESP32_UART0=y
 CONFIG_EXAMPLES_HELLO=y
 CONFIG_EXPERIMENTAL=y
@@ -44,7 +45,6 @@ CONFIG_RAW_BINARY=y
 CONFIG_READLINE_CMD_HISTORY=y
 CONFIG_RR_INTERVAL=200
 CONFIG_SCHED_INSTRUMENTATION=y
-CONFIG_SCHED_INSTRUMENTATION_BUFFER=y
 CONFIG_SDCLONE_DISABLE=y
 CONFIG_SMP=y
 CONFIG_SMP_IDLETHREAD_STACKSIZE=3072

drivers/note/Kconfig

@@ -8,10 +8,37 @@ menu "Note Driver Support"
 config DRIVER_NOTE
 	bool "Scheduler instrumentation driver"
 	default n
-	depends on SCHED_INSTRUMENTATION_BUFFER && SCHED_NOTE_GET
+	depends on !SCHED_INSTRUMENTATION_CSECTION && (!SCHED_INSTRUMENTATION_SPINLOCK || !SMP)
 	---help---
-		Enable building a serial driver that can be used by an application
+		If this option is selected, then in-memory buffering logic is
+		enabled to capture scheduler instrumentation data.  This has
+		the advantage that (1) the platform logic does not have to provide
+		the sched_note_* interfaces described for the previous settings.
+		Instead, the buffering logic catches all of these.  It encodes
+		timestamps the scheduler note and adds the note to an in-memory,
+		circular buffer.  And (2) buffering the scheduler instrumentation
+		data (versus performing some output operation) minimizes the impact
+		of the instrumentation on the behavior of the system. If the in-memory
+		buffer becomes full, then older notes are overwritten by newer notes.
+
+		A character driver is provided which can be used by an application
 		to read data from the in-memory, scheduler instrumentation "note"
 		buffer.
 
+		NOTE: This option is not available if critical sections are being
+		monitor (nor if spinlocks are being monitored in SMP configuration)
+		because there would be a logical error in the design in those cases.
+		That error is that these interfaces call enter_ and leave_critical_section
+		(and which us spinlocks in SMP mode).  That means that each call to
+		sched_note_get() causes several additional entries to be added from
+		the note buffer in order to remove one entry.
+
+config SCHED_NOTE_BUFSIZE
+	int "Instrumentation buffer size"
+	depends on DRIVER_NOTE
+	default 2048
+	---help---
+		The size of the in-memory, circular instrumentation buffer (in
+		bytes).
+
 endmenu

drivers/note/note_driver.c

@@ -44,11 +44,20 @@
 #include <assert.h>
 #include <errno.h>
 
+#include <nuttx/spinlock.h>
 #include <nuttx/sched_note.h>
 #include <nuttx/fs/fs.h>
 
-#if defined(CONFIG_SCHED_INSTRUMENTATION_BUFFER) && \
+/****************************************************************************
-    defined(CONFIG_DRIVER_NOTE)
+ * Private Types
+ ****************************************************************************/
+
+struct note_info_s
+{
+  volatile unsigned int ni_head;
+  volatile unsigned int ni_tail;
+  uint8_t ni_buffer[CONFIG_SCHED_NOTE_BUFSIZE];
+};
 
 /****************************************************************************
  * Private Function Prototypes
@@ -75,10 +84,246 @@ static const struct file_operations note_fops =
 #endif
 };
 
+static struct note_info_s g_note_info;
+
+#ifdef CONFIG_SMP
+static volatile spinlock_t g_note_lock;
+#endif
+
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: note_next
+ *
+ * Description:
+ *   Return the circular buffer index at offset from the specified index
+ *   value, handling wraparound
+ *
+ * Input Parameters:
+ *   ndx - Old circular buffer index
+ *
+ * Returned Value:
+ *   New circular buffer index
+ *
+ ****************************************************************************/
+
+static inline unsigned int note_next(unsigned int ndx, unsigned int offset)
+{
+  ndx += offset;
+  if (ndx >= CONFIG_SCHED_NOTE_BUFSIZE)
+    {
+      ndx -= CONFIG_SCHED_NOTE_BUFSIZE;
+    }
+
+  return ndx;
+}
+
+/****************************************************************************
+ * Name: note_length
+ *
+ * Description:
+ *   Length of data currently in circular buffer.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Length of data currently in circular buffer.
+ *
+ ****************************************************************************/
+
+static unsigned int note_length(void)
+{
+  unsigned int head = g_note_info.ni_head;
+  unsigned int tail = g_note_info.ni_tail;
+
+  if (tail > head)
+    {
+      head += CONFIG_SCHED_NOTE_BUFSIZE;
+    }
+
+  return head - tail;
+}
+
+/****************************************************************************
+ * Name: note_remove
+ *
+ * Description:
+ *   Remove the variable length note from the tail of the circular buffer
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ * Assumptions:
+ *   We are within a critical section.
+ *
+ ****************************************************************************/
+
+static void note_remove(void)
+{
+  FAR struct note_common_s *note;
+  unsigned int tail;
+  unsigned int length;
+
+  /* Get the tail index of the circular buffer */
+
+  tail = g_note_info.ni_tail;
+  DEBUGASSERT(tail < CONFIG_SCHED_NOTE_BUFSIZE);
+
+  /* Get the length of the note at the tail index */
+
+  note   = (FAR struct note_common_s *)&g_note_info.ni_buffer[tail];
+  length = note->nc_length;
+  DEBUGASSERT(length <= note_length());
+
+  /* Increment the tail index to remove the entire note from the circular
+   * buffer.
+   */
+
+  g_note_info.ni_tail = note_next(tail, length);
+}
+
+/****************************************************************************
+ * Name: sched_note_get
+ *
+ * Description:
+ *   Remove the next note from the tail of the circular buffer.  The note
+ *   is also removed from the circular buffer to make room for further notes.
+ *
+ * Input Parameters:
+ *   buffer - Location to return the next note
+ *   buflen - The length of the user provided buffer.
+ *
+ * Returned Value:
+ *   On success, the positive, non-zero length of the return note is
+ *   provided.  Zero is returned only if the circular buffer is empty.  A
+ *   negated errno value is returned in the event of any failure.
+ *
+ ****************************************************************************/
+
+static ssize_t sched_note_get(FAR uint8_t *buffer, size_t buflen)
+{
+  FAR struct note_common_s *note;
+  irqstate_t flags;
+  unsigned int remaining;
+  unsigned int tail;
+  ssize_t notelen;
+  size_t circlen;
+
+  DEBUGASSERT(buffer != NULL);
+  flags = enter_critical_section();
+
+  /* Verify that the circular buffer is not empty */
+
+  circlen = note_length();
+  if (circlen <= 0)
+    {
+      notelen = 0;
+      goto errout_with_csection;
+    }
+
+  /* Get the index to the tail of the circular buffer */
+
+  tail    = g_note_info.ni_tail;
+  DEBUGASSERT(tail < CONFIG_SCHED_NOTE_BUFSIZE);
+
+  /* Get the length of the note at the tail index */
+
+  note    = (FAR struct note_common_s *)&g_note_info.ni_buffer[tail];
+  notelen = note->nc_length;
+  DEBUGASSERT(notelen <= circlen);
+
+  /* Is the user buffer large enough to hold the note? */
+
+  if (buflen < notelen)
+    {
+      /* Remove the large note so that we do not get constipated. */
+
+      note_remove();
+
+      /* and return an error */
+
+      notelen = -EFBIG;
+      goto errout_with_csection;
+    }
+
+  /* Loop until the note has been transferred to the user buffer */
+
+  remaining = (unsigned int)notelen;
+  while (remaining > 0)
+    {
+      /* Copy the next byte at the tail index */
+
+      *buffer++ = g_note_info.ni_buffer[tail];
+
+      /* Adjust indices and counts */
+
+      tail = note_next(tail, 1);
+      remaining--;
+    }
+
+  g_note_info.ni_tail = tail;
+
+errout_with_csection:
+  leave_critical_section(flags);
+  return notelen;
+}
+
+/****************************************************************************
+ * Name: sched_note_size
+ *
+ * Description:
+ *   Return the size of the next note at the tail of the circular buffer.
+ *
+ * Input Parameters:
+ *   None.
+ *
+ * Returned Value:
+ *   Zero is returned if the circular buffer is empty.  Otherwise, the size
+ *   of the next note is returned.
+ *
+ ****************************************************************************/
+
+static ssize_t sched_note_size(void)
+{
+  FAR struct note_common_s *note;
+  irqstate_t flags;
+  unsigned int tail;
+  ssize_t notelen;
+  size_t circlen;
+
+  flags = enter_critical_section();
+
+  /* Verify that the circular buffer is not empty */
+
+  circlen = note_length();
+  if (circlen <= 0)
+    {
+      notelen = 0;
+      goto errout_with_csection;
+    }
+
+  /* Get the index to the tail of the circular buffer */
+
+  tail = g_note_info.ni_tail;
+  DEBUGASSERT(tail < CONFIG_SCHED_NOTE_BUFSIZE);
+
+  /* Get the length of the note at the tail index */
+
+  note    = (FAR struct note_common_s *)&g_note_info.ni_buffer[tail];
+  notelen = note->nc_length;
+  DEBUGASSERT(notelen <= circlen);
+
+errout_with_csection:
+  leave_critical_section(flags);
+  return notelen;
+}
+
 /****************************************************************************
  * Name: note_read
  ****************************************************************************/
@@ -143,6 +388,71 @@ static ssize_t note_read(FAR struct file *filep, FAR char *buffer,
  * Public Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: note_add
+ *
+ * Description:
+ *   Add the variable length note to the transport layer
+ *
+ * Input Parameters:
+ *   note    - The note buffer
+ *   notelen - The buffer length
+ *
+ * Returned Value:
+ *   None
+ *
+ * Assumptions:
+ *   We are within a critical section.
+ *
+ ****************************************************************************/
+
+void note_add(FAR const uint8_t *note, uint8_t notelen)
+{
+  unsigned int head;
+  unsigned int next;
+
+#ifdef CONFIG_SMP
+  irqstate_t flags = up_irq_save();
+  spin_lock_wo_note(&g_note_lock);
+#endif
+
+  /* Get the index to the head of the circular buffer */
+
+  DEBUGASSERT(note != NULL && notelen < CONFIG_SCHED_NOTE_BUFSIZE);
+  head = g_note_info.ni_head;
+
+  /* Loop until all bytes have been transferred to the circular buffer */
+
+  while (notelen > 0)
+    {
+      /* Get the next head index.  Would it collide with the current tail
+       * index?
+       */
+
+      next = note_next(head, 1);
+      if (next == g_note_info.ni_tail)
+        {
+          /* Yes, then remove the note at the tail index */
+
+          note_remove();
+        }
+
+      /* Save the next byte at the head index */
+
+      g_note_info.ni_buffer[head] = *note++;
+
+      head = next;
+      notelen--;
+    }
+
+  g_note_info.ni_head = head;
+
+#ifdef CONFIG_SMP
+  spin_unlock_wo_note(&g_note_lock);
+  up_irq_restore(flags);
+#endif
+}
+
 /****************************************************************************
  * Name: note_register
  *
@@ -163,5 +473,3 @@ int note_register(void)
 {
   return register_driver("/dev/note", &note_fops, 0666, NULL);
 }
-
-#endif /* CONFIG_SCHED_INSTRUMENTATION_BUFFER && CONFIG_DRIVER_NOTE */

include/nuttx/sched_note.h

@@ -48,16 +48,10 @@
 #  define CONFIG_SCHED_INSTRUMENTATION_CPUSET 0xffff
 #endif
 
-#ifndef CONFIG_SCHED_NOTE_BUFSIZE
-#  define CONFIG_SCHED_NOTE_BUFSIZE 2048
-#endif
-
 /****************************************************************************
  * Public Types
  ****************************************************************************/
 
-#ifdef CONFIG_SCHED_INSTRUMENTATION_BUFFER
-
 /* This type identifies a note structure */
 
 enum note_type_e
@@ -259,7 +253,6 @@ struct note_irqhandler_s
   uint8_t nih_irq;              /* IRQ number */
 };
 #endif /* CONFIG_SCHED_INSTRUMENTATION_IRQHANDLER */
-#endif /* CONFIG_SCHED_INSTRUMENTATION_BUFFER */
 
 /****************************************************************************
  * Public Function Prototypes
@@ -273,10 +266,6 @@ struct note_irqhandler_s
  *   logic must provide the following interfaces.  These interfaces are not
  *   available to application code.
  *
- *   NOTE: if CONFIG_SCHED_INSTRUMENTATION_BUFFER, then these interfaces are
- *   *not* available to the platform-specific logic.  Rather, they provided
- *   by the note buffering logic.  See sched_note_get() below.
- *
  * Input Parameters:
  *   tcb - The TCB of the thread.
  *
@@ -349,47 +338,24 @@ void sched_note_irqhandler(int irq, FAR void *handler, bool enter);
 #endif
 
 /****************************************************************************
- * Name: sched_note_get
+ * Name: note_add
  *
  * Description:
- *   Remove the next note from the tail of the circular buffer.  The note
+ *   Add the variable length note to the transport layer
- *   is also removed from the circular buffer to make room for further notes.
  *
  * Input Parameters:
- *   buffer - Location to return the next note
+ *   note    - The note buffer
- *   buflen - The length of the user provided buffer.
+ *   notelen - The buffer length
  *
  * Returned Value:
- *   On success, the positive, non-zero length of the return note is
+ *   None
- *   provided.  Zero is returned only if the circular buffer is empty.  A
+ *
- *   negated errno value is returned in the event of any failure.
+ * Assumptions:
+ *   We are within a critical section.
  *
  ****************************************************************************/
 
-#if defined(CONFIG_SCHED_INSTRUMENTATION_BUFFER) && \
+void note_add(FAR const uint8_t *note, uint8_t notelen);
-    defined(CONFIG_SCHED_NOTE_GET)
-ssize_t sched_note_get(FAR uint8_t *buffer, size_t buflen);
-#endif
-
-/****************************************************************************
- * Name: sched_note_size
- *
- * Description:
- *   Return the size of the next note at the tail of the circular buffer.
- *
- * Input Parameters:
- *   None.
- *
- * Returned Value:
- *   Zero is returned if the circular buffer is empty.  Otherwise, the size
- *   of the next note is returned.
- *
- ****************************************************************************/
-
-#if defined(CONFIG_SCHED_INSTRUMENTATION_BUFFER) && \
-    defined(CONFIG_SCHED_NOTE_GET)
-ssize_t sched_note_size(void);
-#endif
 
 #else /* CONFIG_SCHED_INSTRUMENTATION */
 

sched/Kconfig

@@ -914,8 +914,6 @@ config SCHED_INSTRUMENTATION
 		done in these interfaces.  For example, normal devices may not be
 		used; syslog output cannot be performed.
 
-		An option is to use SCHED_INSTRUMENTATION_BUFFER below.
-
 if SCHED_INSTRUMENTATION
 
 config SCHED_INSTRUMENTATION_CPUSET
@@ -977,59 +975,6 @@ config SCHED_INSTRUMENTATION_IRQHANDLER
 
 			void sched_note_irqhandler(int irq, FAR void *handler, bool enter);
 
-config SCHED_INSTRUMENTATION_BUFFER
-	bool "Buffer instrumentation data in memory"
-	default n
-	---help---
-		If this option is selected, then in-memory buffering logic is
-		enabled to capture scheduler instrumentation data.  This has
-		the advantage that (1) the platform logic does not have to provide
-		the sched_note_* interfaces described for the previous settings.
-		Instead, the buffering logic catches all of these.  It encodes
-		timestamps the scheduler note and adds the note to an in-memory,
-		circular buffer.  And (2) buffering the scheduler instrumentation
-		data (versus performing some output operation) minimizes the impact
-		of the instrumentation on the behavior of the system.
-
-		If the in-memory buffer becomes full, then older notes are
-		overwritten by newer notes.  The following interface is provided:
-
-			ssize_t sched_note_get(FAR uint8_t *buffer, size_t buflen);
-
-		Platform specific information must call this function and dispose
-		of it quickly so that overwriting of the tail of the circular buffer
-		does not occur.  See include/nuttx/sched_note.h for additional
-		information.
-
-if SCHED_INSTRUMENTATION_BUFFER
-
-config SCHED_NOTE_BUFSIZE
-	int "Instrumentation buffer size"
-	default 2048
-	---help---
-		The size of the in-memory, circular instrumentation buffer (in
-		bytes).
-
-config SCHED_NOTE_GET
-	bool "Callable interface to get instrumentation data"
-	default n
-	depends on !SCHED_INSTRUMENTATION_CSECTION && (!SCHED_INSTRUMENTATION_SPINLOCK || !SMP)
-	---help---
-		Add support for interfaces to get the size of the next note and also
-		to extract the next note from the instrumentation buffer:
-
-			ssize_t sched_note_get(FAR uint8_t *buffer, size_t buflen);
-			ssize_t sched_note_size(void);
-
-		NOTE: This option is not available if critical sections are being
-		monitor (nor if spinlocks are being monitored in SMP configuration)
-		because there would be a logical error in the design in those cases.
-		That error is that these interfaces call enter_ and leave_critical_section
-		(and which us spinlocks in SMP mode).  That means that each call to
-		sched_note_get() causes several additional entries to be added from
-		the note buffer in order to remove one entry.
-
-endif # SCHED_INSTRUMENTATION_BUFFER
 endif # SCHED_INSTRUMENTATION
 endmenu # Performance Monitoring
 

sched/sched/Make.defs

@@ -89,7 +89,7 @@ CSRCS += sched_tasklistlock.c
 CSRCS += sched_thistask.c
 endif
 
-ifeq ($(CONFIG_SCHED_INSTRUMENTATION_BUFFER),y)
+ifeq ($(CONFIG_SCHED_INSTRUMENTATION),y)
 CSRCS += sched_note.c
 endif