sergiotarxz/nuttx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

include/nuttx/clock.h, sched/sched: Support the CPU load measurement using timer_lowerhalf_s interface

Browse Source
This commit is contained in:
Xiang Xiao 2018-08-24 10:10:57 -06:00 committed by Gregory Nutt
parent 0074afa0ac
commit 3af35699b9
5 changed files with 311 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
include/nuttx/clock.h
View File

@ -426,6 +426,28 @@ struct oneshot_lowerhalf_s;
void sched_oneshot_extclk(FAR struct oneshot_lowerhalf_s *lower);
#endif
/****************************************************************************
* Name: sched_period_extclk
*
* Description:
* Configure to use a period timer as described in
* include/nuttx/timers/timer.h to provide external clocking to assess
* the CPU load.
*
* Input Parameters:
* lower - An instance of the period timer interface as defined in
* include/nuttx/timers/timer.h
*
* Returned Value:
* None
*
****************************************************************************/
#ifdef CONFIG_CPULOAD_PERIOD
struct timer_lowerhalf_s;
void sched_period_extclk(FAR struct timer_lowerhalf_s *lower);
#endif
#undef EXTERN
#ifdef __cplusplus
}

26
sched/Kconfig
View File

@ -729,6 +729,10 @@ config SCHED_CPULOAD_TICKSPERSEC
that 100Hz is the default frequency of the system time and, hence,
the worst possible choice in most cases.
choice
prompt "Select CPU load timer"
default CPULOAD_ONESHOT
config CPULOAD_ONESHOT
bool "Use Oneshot timer"
default n
@ -748,7 +752,25 @@ config CPULOAD_ONESHOT
significantly faster than CONFIG_SCHED_CPULOAD_TICKSPERSE to permit
precise modulation the sample periods.
config CPULOAD_ONESHOT_ENTROPY
config CPULOAD_PERIOD
bool "Use Period timer"
default n
---help---
Use an MCU-specific period timer as the external clock. The
period timer must be configured by board specific logic which must
then call:
void sched_period_extclk(FAR struct timer_lowerhalf_s *lower);
To start the CPU load measurement. See include/nuttx/clock.h
NOTE that in this configuration, CONFIG_SCHED_CPULOAD_TICKSPERSEC is
the sample rate that will be accomplished by programming the period
time.
endchoice
config CPULOAD_ENTROPY
int "Bits of entropy"
default 6
range 0 30
@ -764,7 +786,7 @@ config CPULOAD_ONESHOT_ENTROPY
CPULOAD_ONESHOT_NOMINAL is the nominal sample interval implied
by CONFIG_SCHED_CPULOAD_TICKSPERSEC in units of microseconds.
CPULOAD_ONESHOT_ENTROPY is (1 << CONFIG_CPULOAD_ONESHOT_ENTROPY),
CPULOAD_ONESHOT_ENTROPY is (1 << CONFIG_CPULOAD_ENTROPY),
and 'error' is an error value that is retained from interval to
interval so that although individual intervals are randomized,
the average will still be CONFIG_SCHED_CPULOAD_TICKSPERSEC.

3
sched/sched/Make.defs
View File

@ -86,6 +86,9 @@ CSRCS += sched_cpuload.c
ifeq ($(CONFIG_CPULOAD_ONESHOT),y)
CSRCS += sched_cpuload_oneshot.c
endif
ifeq ($(CONFIG_CPULOAD_PERIOD),y)
CSRCS += sched_cpuload_period.c
endif
endif
ifeq ($(CONFIG_SCHED_TICKLESS),y)

24
sched/sched/sched_cpuload_oneshot.c
View File

@ -70,14 +70,14 @@
# error CONFIG_SCHED_CPULOAD_TICKSPERSEC not defined
#endif
/* CONFIG_CPULOAD_ONESHOT_ENTROPY determines that amount of random "jitter"
/* CONFIG_CPULOAD_ENTROPY determines that amount of random "jitter"
* that will be added to the nominal sample interval. Specified as a number
* bits.
*/
#ifndef CONFIG_CPULOAD_ONESHOT_ENTROPY
# warning CONFIG_CPULOAD_ONESHOT_ENTROPY not defined
# define CONFIG_CPULOAD_ONESHOT_ENTROPY 0
#ifndef CONFIG_CPULOAD_ENTROPY
# warning CONFIG_CPULOAD_ENTROPY not defined
# define CONFIG_CPULOAD_ENTROPY 0
#endif
/* Calculate the nomimal sample interval in microseconds:
@ -93,10 +93,10 @@
/* Convert the entropy from number of bits to a numeric value */
#define CPULOAD_ONESHOT_ENTROPY (1 << CONFIG_CPULOAD_ONESHOT_ENTROPY)
#define CPULOAD_ONESHOT_ENTROPY (1 << CONFIG_CPULOAD_ENTROPY)
#if CPULOAD_ONESHOT_NOMINAL < CPULOAD_ONESHOT_ENTROPY
# error CPULOAD_ONESHOT_NOMINAL too small for CONFIG_CPULOAD_ONESHOT_ENTROPY
# error CPULOAD_ONESHOT_NOMINAL too small for CONFIG_CPULOAD_ENTROPY
#endif
#define CPULOAD_ONESHOT_ENTROPY_MASK (CPULOAD_ONESHOT_ENTROPY - 1)
@ -108,7 +108,7 @@
struct sched_oneshot_s
{
FAR struct oneshot_lowerhalf_s *oneshot;
#if CONFIG_CPULOAD_ONESHOT_ENTROPY > 0
#if CONFIG_CPULOAD_ENTROPY > 0
struct xorshift128_state_s prng;
int32_t maxdelay;
int32_t error;
@ -152,7 +152,7 @@ static struct sched_oneshot_s g_sched_oneshot;
static void sched_oneshot_start(void)
{
struct timespec ts;
#if CONFIG_CPULOAD_ONESHOT_ENTROPY > 0
#if CONFIG_CPULOAD_ENTROPY > 0
uint32_t entropy;
#endif
int32_t secs;
@ -160,7 +160,7 @@ static void sched_oneshot_start(void)
/* Get the next delay */
#if CONFIG_CPULOAD_ONESHOT_ENTROPY > 0
#if CONFIG_CPULOAD_ENTROPY > 0
/* The one shot will be set to this interval:
*
* CPULOAD_ONESHOT_NOMINAL - (CPULOAD_ONESHOT_ENTROPY / 2) + error
@ -234,7 +234,6 @@ static void sched_oneshot_callback(FAR struct oneshot_lowerhalf_s *lower,
{
sched_process_cpuload();
}
#endif
/* Then restart the oneshot */
@ -264,14 +263,14 @@ static void sched_oneshot_callback(FAR struct oneshot_lowerhalf_s *lower,
void sched_oneshot_extclk(FAR struct oneshot_lowerhalf_s *lower)
{
#if CONFIG_CPULOAD_ONESHOT_ENTROPY > 0
#if CONFIG_CPULOAD_ENTROPY > 0
struct timespec ts;
#endif
DEBUGASSERT(lower != NULL && lower->ops != NULL);
DEBUGASSERT(lower->ops->start != NULL);
#if CONFIG_CPULOAD_ONESHOT_ENTROPY > 0
#if CONFIG_CPULOAD_ENTROPY > 0
DEBUGASSERT(lower->ops->max_delay != NULL);
/* Get the maximum delay */
@ -302,3 +301,4 @@ void sched_oneshot_extclk(FAR struct oneshot_lowerhalf_s *lower)
g_sched_oneshot.oneshot = lower;
sched_oneshot_start();
}
#endif

250
sched/sched/sched_cpuload_period.c Normal file
View File

@ -0,0 +1,250 @@
/****************************************************************************
* sched/sched/sched_cpuload_period.c
*
* Copyright (C) 2018 Pinecone Inc. All rights reserved.
* Author: Xiang Xiao <xiaoxiang@pinecone.net>
*
* 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 <assert.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/clock.h>
#include <nuttx/lib/xorshift128.h>
#include <nuttx/timers/timer.h>
#ifdef CONFIG_CPULOAD_PERIOD
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#if !defined(CONFIG_SCHED_CPULOAD) || !defined(CONFIG_SCHED_CPULOAD_EXTCLK)
# error CONFIG_SCHED_CPULOAD and CONFIG_SCHED_CPULOAD_EXTCLK must be defined
#endif
/* CONFIG_SCHED_CPULOAD_TICKSPERSEC is the frequency of the external clock
* source.
*/
#ifndef CONFIG_SCHED_CPULOAD_TICKSPERSEC
# error CONFIG_SCHED_CPULOAD_TICKSPERSEC not defined
#endif
/* CONFIG_CPULOAD_ENTROPY determines that amount of random "jitter"
* that will be added to the nominal sample interval. Specified as a number
* bits.
*/
#ifndef CONFIG_CPULOAD_ENTROPY
# warning CONFIG_CPULOAD_ENTROPY not defined
# define CONFIG_CPULOAD_ENTROPY 0
#endif
/* Calculate the nomimal sample interval in microseconds:
*
* nominal = (1,000,000 usec/sec) / Frequency cycles/sec) = Period usec/cycle
*/
#define CPULOAD_PERIOD_NOMINAL (1000000 / CONFIG_SCHED_CPULOAD_TICKSPERSEC)
#if CPULOAD_PERIOD_NOMINAL < 1 || CPULOAD_PERIOD_NOMINAL > 0x7fffffff
# error CPULOAD_PERIOD_NOMINAL is out of range
#endif
/* Convert the entropy from number of bits to a numeric value */
#define CPULOAD_PERIOD_ENTROPY (1 << CONFIG_CPULOAD_ENTROPY)
#if CPULOAD_PERIOD_NOMINAL < CPULOAD_PERIOD_ENTROPY
# error CPULOAD_PERIOD_NOMINAL too small for CONFIG_CPULOAD_ENTROPY
#endif
#define CPULOAD_PERIOD_ENTROPY_MASK (CPULOAD_PERIOD_ENTROPY - 1)
/****************************************************************************
* Private Types
****************************************************************************/
#if CONFIG_CPULOAD_ENTROPY > 0
struct sched_period_s
{
struct xorshift128_state_s prng;
uint32_t maxtimeout;
int32_t error;
};
#endif
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static bool sched_period_callback(FAR uint32_t *next_interval_us,
FAR void *arg);
/****************************************************************************
* Private Data
****************************************************************************/
#if CONFIG_CPULOAD_ENTROPY > 0
static struct sched_period_s g_sched_period;
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: sched_period_callback
*
* Description:
* This is the callback function that will be invoked when the period
* timer expires.
*
* Input Parameters:
* next_interval_us - The timeout value for next interval
* arg - The opaque argument provided when the callback was registered
*
* Returned Value:
* return false to stop the timer, true to continue the timing
*
****************************************************************************/
static bool sched_period_callback(FAR uint32_t *next_interval_us,
FAR void *arg)
{
/* Get the next delay */
#if CONFIG_CPULOAD_ENTROPY > 0
/* The period timer will be set to this interval:
*
* CPULOAD_PERIOD_NOMINAL - (CPULOAD_PERIOD_ENTROPY / 2) + error
* + nrand(CPULOAD_PERIOD_ENTROPY)
*/
*next_interval_us = CPULOAD_PERIOD_NOMINAL - CPULOAD_PERIOD_ENTROPY / 2 +
g_sched_period.error;
/* Add the random value in the range 0..(CPULOAD_PERIOD_ENTROPY - 1) */
*next_interval_us += xorshift128(&g_sched_period.prng) &
CPULOAD_PERIOD_ENTROPY_MASK;
DEBUGASSERT(*next_interval_us > 0); /* Check for overflow to negative or zero */
/* Make sure that the accumulated value does not exceed the maximum timeout */
if (*next_interval_us > g_sched_period.maxtimeout)
{
tmrwarn("WARNING: Truncating\n");
*next_interval_us = g_sched_period.maxtimeout;
}
/* Save the new error value */
g_sched_period.error = CPULOAD_PERIOD_NOMINAL +
g_sched_period.error - *next_interval_us;
#endif
/* Perform CPU load measurements */
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (sched_process_cpuload != NULL)
#endif
{
sched_process_cpuload();
}
/* Then continue the timing */
return true;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: sched_period_extclk
*
* Description:
* Configure to use a period timer as described in
* include/nuttx/timers/timer.h to provide external clocking to assess
* the CPU load.
*
* Input Parameters:
* lower - An instance of the period timer interface as defined in
* include/nuttx/timers/timer.h
*
* Returned Value:
* None
*
****************************************************************************/
void sched_period_extclk(FAR struct timer_lowerhalf_s *lower)
{
DEBUGASSERT(lower != NULL && lower->ops != NULL);
DEBUGASSERT(lower->ops->setcallback != NULL);
DEBUGASSERT(lower->ops->settimeout != NULL);
DEBUGASSERT(lower->ops->start != NULL);
#if CONFIG_CPULOAD_ENTROPY > 0
DEBUGASSERT(lower->ops->maxtimeout != NULL);
/* Get the maximum timeout */
DEBUGVERIFY(lower->ops->maxtimeout(lower, &g_sched_period.maxtimeout));
tmrinfo("maxtimeout = %lu usec\n", (long)g_sched_period.maxtimeout);
DEBUGASSERT(CPULOAD_PERIOD_NOMINAL < g_sched_period.maxtimeout);
/* Seed the PRNG */
g_sched_period.prng.w = 97;
g_sched_period.prng.x = 101;
g_sched_period.prng.y = g_sched_period.prng.w << 17;
g_sched_period.prng.z = g_sched_period.prng.x << 25;
#endif
/* Then start the period timer */
lower->ops->setcallback(lower, sched_period_callback, NULL);
lower->ops->settimeout(lower, CPULOAD_PERIOD_NOMINAL);
lower->ops->start(lower);
}
#endif