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Posted to commits@nuttx.apache.org by li...@apache.org on 2020/09/07 03:54:23 UTC

[incubator-nuttx] 02/02: sched/note: Move the circle buffer code to driver

This is an automated email from the ASF dual-hosted git repository.

liuhaitao pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git

commit 952af92690860b9d47c21144576f46a3ce425c8c
Author: Xiang Xiao <xi...@xiaomi.com>
AuthorDate: Fri Aug 7 02:57:30 2020 +0800

    sched/note: Move the circle buffer code to driver
    
    so the format code can be shared by different transport
    
    Signed-off-by: Xiang Xiao <xi...@xiaomi.com>
---
 boards/arm/cxd56xx/spresense/configs/smp/defconfig |   2 +-
 boards/arm/imx6/sabre-6quad/configs/smp/defconfig  |   2 +-
 .../lc823450/lc823450-xgevk/configs/bt/defconfig   |   2 +-
 .../lc823450/lc823450-xgevk/configs/elf/defconfig  |   2 +-
 .../lc823450/lc823450-xgevk/configs/ipl2/defconfig |   2 +-
 .../lc823450/lc823450-xgevk/configs/knsh/defconfig |   2 +-
 .../lc823450-xgevk/configs/krndis/defconfig        |   2 +-
 .../lc823450/lc823450-xgevk/configs/nsh/defconfig  |   2 +-
 .../lc823450-xgevk/configs/posix_spawn/defconfig   |   2 +-
 .../lc823450-xgevk/configs/rndis/defconfig         |   2 +-
 .../lc823450/lc823450-xgevk/configs/usb/defconfig  |   2 +-
 .../arm/stm32f7/stm32f746-ws/configs/nsh/defconfig |   2 +-
 boards/risc-v/k210/maix-bit/configs/smp/defconfig  |   2 +-
 .../xtensa/esp32/esp32-core/configs/smp/defconfig  |   2 +-
 drivers/note/Kconfig                               |  31 +-
 drivers/note/note_driver.c                         | 316 ++++++++++++-
 include/nuttx/sched_note.h                         |  50 +-
 sched/Kconfig                                      |  55 ---
 sched/sched/Make.defs                              |   2 +-
 sched/sched/sched_note.c                           | 512 +++++++--------------
 20 files changed, 539 insertions(+), 455 deletions(-)

diff --git a/boards/arm/cxd56xx/spresense/configs/smp/defconfig b/boards/arm/cxd56xx/spresense/configs/smp/defconfig
index 5c64e24..051902d 100644
--- a/boards/arm/cxd56xx/spresense/configs/smp/defconfig
+++ b/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
diff --git a/boards/arm/imx6/sabre-6quad/configs/smp/defconfig b/boards/arm/imx6/sabre-6quad/configs/smp/defconfig
index 402f4df..4f60ebf 100644
--- a/boards/arm/imx6/sabre-6quad/configs/smp/defconfig
+++ b/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
diff --git a/boards/arm/lc823450/lc823450-xgevk/configs/bt/defconfig b/boards/arm/lc823450/lc823450-xgevk/configs/bt/defconfig
index 7aa6eda..b33a866 100644
--- a/boards/arm/lc823450/lc823450-xgevk/configs/bt/defconfig
+++ b/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
diff --git a/boards/arm/lc823450/lc823450-xgevk/configs/elf/defconfig b/boards/arm/lc823450/lc823450-xgevk/configs/elf/defconfig
index 128a580..3e61fd7 100644
--- a/boards/arm/lc823450/lc823450-xgevk/configs/elf/defconfig
+++ b/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
diff --git a/boards/arm/lc823450/lc823450-xgevk/configs/ipl2/defconfig b/boards/arm/lc823450/lc823450-xgevk/configs/ipl2/defconfig
index b48c9f0..5b6604d 100644
--- a/boards/arm/lc823450/lc823450-xgevk/configs/ipl2/defconfig
+++ b/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
diff --git a/boards/arm/lc823450/lc823450-xgevk/configs/knsh/defconfig b/boards/arm/lc823450/lc823450-xgevk/configs/knsh/defconfig
index bfeb8c8..767ea4e 100644
--- a/boards/arm/lc823450/lc823450-xgevk/configs/knsh/defconfig
+++ b/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
diff --git a/boards/arm/lc823450/lc823450-xgevk/configs/krndis/defconfig b/boards/arm/lc823450/lc823450-xgevk/configs/krndis/defconfig
index 9a09a07..84a0087 100644
--- a/boards/arm/lc823450/lc823450-xgevk/configs/krndis/defconfig
+++ b/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
diff --git a/boards/arm/lc823450/lc823450-xgevk/configs/nsh/defconfig b/boards/arm/lc823450/lc823450-xgevk/configs/nsh/defconfig
index 92e108e..80e15ae 100644
--- a/boards/arm/lc823450/lc823450-xgevk/configs/nsh/defconfig
+++ b/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
diff --git a/boards/arm/lc823450/lc823450-xgevk/configs/posix_spawn/defconfig b/boards/arm/lc823450/lc823450-xgevk/configs/posix_spawn/defconfig
index 4825e61..69a464e 100644
--- a/boards/arm/lc823450/lc823450-xgevk/configs/posix_spawn/defconfig
+++ b/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
diff --git a/boards/arm/lc823450/lc823450-xgevk/configs/rndis/defconfig b/boards/arm/lc823450/lc823450-xgevk/configs/rndis/defconfig
index 4887b02..8a0cc44 100644
--- a/boards/arm/lc823450/lc823450-xgevk/configs/rndis/defconfig
+++ b/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
diff --git a/boards/arm/lc823450/lc823450-xgevk/configs/usb/defconfig b/boards/arm/lc823450/lc823450-xgevk/configs/usb/defconfig
index c1a8e78..2d636e7 100644
--- a/boards/arm/lc823450/lc823450-xgevk/configs/usb/defconfig
+++ b/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
diff --git a/boards/arm/stm32f7/stm32f746-ws/configs/nsh/defconfig b/boards/arm/stm32f7/stm32f746-ws/configs/nsh/defconfig
index df3b8c9..024d65f 100644
--- a/boards/arm/stm32f7/stm32f746-ws/configs/nsh/defconfig
+++ b/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
diff --git a/boards/risc-v/k210/maix-bit/configs/smp/defconfig b/boards/risc-v/k210/maix-bit/configs/smp/defconfig
index 3eeba6b..249ccb6 100644
--- a/boards/risc-v/k210/maix-bit/configs/smp/defconfig
+++ b/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
diff --git a/boards/xtensa/esp32/esp32-core/configs/smp/defconfig b/boards/xtensa/esp32/esp32-core/configs/smp/defconfig
index 5182655..ffcb2d3 100644
--- a/boards/xtensa/esp32/esp32-core/configs/smp/defconfig
+++ b/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
diff --git a/drivers/note/Kconfig b/drivers/note/Kconfig
index 6865682..3206081 100644
--- a/drivers/note/Kconfig
+++ b/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
diff --git a/drivers/note/note_driver.c b/drivers/note/note_driver.c
index afd37c2..9207609 100644
--- a/drivers/note/note_driver.c
+++ b/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
@@ -75,11 +84,247 @@ 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
  ****************************************************************************/
 
@@ -144,6 +389,71 @@ static ssize_t note_read(FAR struct file *filep, FAR char *buffer,
  ****************************************************************************/
 
 /****************************************************************************
+ * 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
  *
  * Description:
@@ -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 */
diff --git a/include/nuttx/sched_note.h b/include/nuttx/sched_note.h
index 1052a08..68c9946 100644
--- a/include/nuttx/sched_note.h
+++ b/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
- *   is also removed from the circular buffer to make room for further notes.
+ *   Add the variable length note to the transport layer
  *
  * Input Parameters:
- *   buffer - Location to return the next note
- *   buflen - The length of the user provided buffer.
+ *   note    - The note buffer
+ *   notelen - The buffer length
  *
  * 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.
- *
- ****************************************************************************/
-
-#if defined(CONFIG_SCHED_INSTRUMENTATION_BUFFER) && \
-    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.
+ *   None
  *
- * Returned Value:
- *   Zero is returned if the circular buffer is empty.  Otherwise, the size
- *   of the next note is returned.
+ * Assumptions:
+ *   We are within a critical section.
  *
  ****************************************************************************/
 
-#if defined(CONFIG_SCHED_INSTRUMENTATION_BUFFER) && \
-    defined(CONFIG_SCHED_NOTE_GET)
-ssize_t sched_note_size(void);
-#endif
+void note_add(FAR const uint8_t *note, uint8_t notelen);
 
 #else /* CONFIG_SCHED_INSTRUMENTATION */
 
diff --git a/sched/Kconfig b/sched/Kconfig
index c5fcc3c..3e01b93 100644
--- a/sched/Kconfig
+++ b/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
 
diff --git a/sched/sched/Make.defs b/sched/sched/Make.defs
index 9825ac3..57546ac 100644
--- a/sched/sched/Make.defs
+++ b/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
 
diff --git a/sched/sched/sched_note.c b/sched/sched/sched_note.c
index e13a85b..8b20d5b 100644
--- a/sched/sched/sched_note.c
+++ b/sched/sched/sched_note.c
@@ -36,19 +36,10 @@
 
 #include "sched/sched.h"
 
-#ifdef CONFIG_SCHED_INSTRUMENTATION_BUFFER
-
 /****************************************************************************
  * Private Types
  ****************************************************************************/
 
-struct note_info_s
-{
-  volatile unsigned int ni_head;
-  volatile unsigned int ni_tail;
-  uint8_t ni_buffer[CONFIG_SCHED_NOTE_BUFSIZE];
-};
-
 struct note_startalloc_s
 {
   struct note_common_s nsa_cmn; /* Common note parameters */
@@ -64,52 +55,10 @@ struct note_startalloc_s
 #endif
 
 /****************************************************************************
- * Private Function Prototypes
- ****************************************************************************/
-
-static void note_add(FAR const uint8_t *note, uint8_t notelen);
-
-/****************************************************************************
- * Private Data
- ****************************************************************************/
-
-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_common
  *
  * Description:
@@ -167,116 +116,12 @@ static void note_common(FAR struct tcb_s *tcb,
  ****************************************************************************/
 
 #ifdef CONFIG_SCHED_INSTRUMENTATION_SPINLOCKS
-void note_spincommon(FAR struct tcb_s *tcb,
-                     FAR volatile spinlock_t *spinlock,
-                     int type)
+static void note_spincommon(FAR struct tcb_s *tcb,
+                            FAR volatile spinlock_t *spinlock,
+                            int type)
 {
   struct note_spinlock_s note;
 
-  /* Format the note */
-
-  note_common(tcb, &note.nsp_cmn, sizeof(struct note_spinlock_s), type);
-  note.nsp_spinlock = (FAR void *)spinlock;
-  note.nsp_value    = (uint8_t)*spinlock;
-
-  /* Add the note to circular buffer */
-
-  note_add((FAR const uint8_t *)&note, sizeof(struct note_spinlock_s));
-}
-#endif
-
-/****************************************************************************
- * Name: note_length
- *
- * Description:
- *   Length of data currently in circular buffer.
- *
- * Input Parameters:
- *   None
- *
- * Returned Value:
- *   Length of data currently in circular buffer.
- *
- ****************************************************************************/
-
-#if defined(CONFIG_SCHED_NOTE_GET) || defined(CONFIG_DEBUG_ASSERTIONS)
-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;
-}
-#endif
-
-/****************************************************************************
- * 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: note_add
- *
- * Description:
- *   Add the variable length note to the head of the circular buffer
- *
- * Input Parameters:
- *   None
- *
- * Returned Value:
- *   None
- *
- * Assumptions:
- *   We are within a critical section.
- *
- ****************************************************************************/
-
-static void note_add(FAR const uint8_t *note, uint8_t notelen)
-{
-  unsigned int head;
-  unsigned int next;
-
 #ifdef CONFIG_SMP
   /* Ignore notes that are not in the set of monitored CPUs */
 
@@ -288,47 +133,17 @@ static void note_add(FAR const uint8_t *note, uint8_t notelen)
     }
 #endif
 
-#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++;
+  /* Format the note */
 
-      head = next;
-      notelen--;
-    }
+  note_common(tcb, &note.nsp_cmn, sizeof(struct note_spinlock_s), type);
+  note.nsp_spinlock = (FAR void *)spinlock;
+  note.nsp_value    = (uint8_t)*spinlock;
 
-  g_note_info.ni_head = head;
+  /* Add the note to circular buffer */
 
-#ifdef CONFIG_SMP
-  spin_unlock_wo_note(&g_note_lock);
-  up_irq_restore(flags);
-#endif
+  note_add((FAR const uint8_t *)&note, sizeof(struct note_spinlock_s));
 }
+#endif
 
 /****************************************************************************
  * Public Functions
@@ -361,6 +176,17 @@ void sched_note_start(FAR struct tcb_s *tcb)
   int namelen;
 #endif
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Copy the task name (if possible) and get the length of the note */
 
 #if CONFIG_TASK_NAME_SIZE > 0
@@ -387,6 +213,17 @@ void sched_note_stop(FAR struct tcb_s *tcb)
 {
   struct note_stop_s note;
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.nsp_cmn, sizeof(struct note_stop_s), NOTE_STOP);
@@ -400,6 +237,17 @@ void sched_note_suspend(FAR struct tcb_s *tcb)
 {
   struct note_suspend_s note;
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.nsu_cmn, sizeof(struct note_suspend_s),
@@ -415,6 +263,17 @@ void sched_note_resume(FAR struct tcb_s *tcb)
 {
   struct note_resume_s note;
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.nre_cmn, sizeof(struct note_resume_s), NOTE_RESUME);
@@ -429,6 +288,17 @@ void sched_note_cpu_start(FAR struct tcb_s *tcb, int cpu)
 {
   struct note_cpu_start_s note;
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.ncs_cmn, sizeof(struct note_cpu_start_s),
@@ -444,6 +314,17 @@ void sched_note_cpu_started(FAR struct tcb_s *tcb)
 {
   struct note_cpu_started_s note;
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.ncs_cmn, sizeof(struct note_cpu_started_s),
@@ -458,6 +339,17 @@ void sched_note_cpu_pause(FAR struct tcb_s *tcb, int cpu)
 {
   struct note_cpu_pause_s note;
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.ncp_cmn, sizeof(struct note_cpu_pause_s),
@@ -473,6 +365,17 @@ void sched_note_cpu_paused(FAR struct tcb_s *tcb)
 {
   struct note_cpu_paused_s note;
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.ncp_cmn, sizeof(struct note_cpu_paused_s),
@@ -487,6 +390,17 @@ void sched_note_cpu_resume(FAR struct tcb_s *tcb, int cpu)
 {
   struct note_cpu_resume_s note;
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.ncr_cmn, sizeof(struct note_cpu_resume_s),
@@ -502,6 +416,17 @@ void sched_note_cpu_resumed(FAR struct tcb_s *tcb)
 {
   struct note_cpu_resumed_s note;
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.ncr_cmn, sizeof(struct note_cpu_resumed_s),
@@ -518,6 +443,17 @@ void sched_note_premption(FAR struct tcb_s *tcb, bool locked)
 {
   struct note_preempt_s note;
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.npr_cmn, sizeof(struct note_preempt_s),
@@ -536,6 +472,17 @@ void sched_note_csection(FAR struct tcb_s *tcb, bool enter)
 {
   struct note_csection_s note;
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.ncs_cmn, sizeof(struct note_csection_s),
@@ -581,6 +528,17 @@ void sched_note_syscall_enter(int nr, int argc, ...)
   struct note_syscall_enter_s note;
   FAR struct tcb_s *tcb = this_task();
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.nsc_cmn, sizeof(struct note_syscall_enter_s),
@@ -598,6 +556,17 @@ void sched_note_syscall_leave(int nr, uintptr_t result)
   struct note_syscall_leave_s note;
   FAR struct tcb_s *tcb = this_task();
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.nsc_cmn, sizeof(struct note_syscall_leave_s),
@@ -618,6 +587,17 @@ void sched_note_irqhandler(int irq, FAR void *handler, bool enter)
   struct note_irqhandler_s note;
   FAR struct tcb_s *tcb = this_task();
 
+#ifdef CONFIG_SMP
+  /* Ignore notes that are not in the set of monitored CPUs */
+
+  if ((CONFIG_SCHED_INSTRUMENTATION_CPUSET & (1 << this_cpu())) == 0)
+    {
+      /* Not in the set of monitored CPUs.  Do not log the note. */
+
+      return;
+    }
+#endif
+
   /* Format the note */
 
   note_common(tcb, &note.nih_cmn, sizeof(struct note_irqhandler_s),
@@ -630,145 +610,3 @@ void sched_note_irqhandler(int irq, FAR void *handler, bool enter)
   note_add((FAR const uint8_t *)&note, sizeof(struct note_irqhandler_s));
 }
 #endif
-
-/****************************************************************************
- * 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.
- *
- ****************************************************************************/
-
-#ifdef CONFIG_SCHED_NOTE_GET
-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;
-}
-#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.
- *
- ****************************************************************************/
-
-#ifdef CONFIG_SCHED_NOTE_GET
-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;
-}
-#endif
-
-#endif /* CONFIG_SCHED_INSTRUMENTATION_BUFFER */