cpuload.c

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/**
 * @file cpuload.c
 *
 * Measurement of CPU load of each individual task.
 *
 * @author Lorenz Meier <lorenz@px4.io>
 * @author Petri Tanskanen <petri.tanskanen@inf.ethz.ch>
 */
#include <px4_platform_common/px4_config.h>

#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>

//#include <arch/arch.h>

//#include <debug.h>

#include <sys/time.h>

#include <arch/board/board.h>
#include <drivers/drv_hrt.h>

#include "cpuload.h"

#ifdef CONFIG_SCHED_INSTRUMENTATION

#ifdef __PX4_NUTTX

# include <nuttx/sched_note.h>

void sched_note_suspend(FAR struct tcb_s *tcb);
void sched_note_resume(FAR struct tcb_s *tcb);

__EXPORT void sched_note_switch(FAR struct tcb_s *pFromTcb, FAR struct tcb_s *pToTcb);

__EXPORT struct system_load_s system_load;

extern FAR struct tcb_s *sched_gettcb(pid_t pid);

void cpuload_initialize_once()
{
    system_load.start_time = hrt_absolute_time();
    int i;

    for (i = 0; i < CONFIG_MAX_TASKS; i++) {
        system_load.tasks[i].valid = false;
    }

    int static_tasks_count = 2; // there are at least 2 threads that should be initialized statically - "idle" and "init"

#ifdef CONFIG_PAGING
    static_tasks_count++;   // include paging thread in initialization
#endif /* CONFIG_PAGING */
#if CONFIG_SCHED_WORKQUEUE
    static_tasks_count++;   // include high priority work0 thread in initialization
#endif /* CONFIG_SCHED_WORKQUEUE */
#if CONFIG_SCHED_LPWORK
    static_tasks_count++;   // include low priority work1 thread in initialization
#endif /* CONFIG_SCHED_WORKQUEUE */

    // perform static initialization of "system" threads
    for (system_load.total_count = 0; system_load.total_count < static_tasks_count; system_load.total_count++) {
        system_load.tasks[system_load.total_count].total_runtime = 0;
        system_load.tasks[system_load.total_count].curr_start_time = 0;
        system_load.tasks[system_load.total_count].tcb = sched_gettcb(
                    system_load.total_count);   // it is assumed that these static threads have consecutive PIDs
        system_load.tasks[system_load.total_count].valid = true;
    }

    system_load.initialized = true;
}

void sched_note_start(FAR struct tcb_s *tcb)
{
    /* search first free slot */
    int i;

    if (system_load.initialized) {
        for (i = 1; i < CONFIG_MAX_TASKS; i++) {
            if (!system_load.tasks[i].valid) {
                /* slot is available */
                system_load.tasks[i].total_runtime = 0;
                system_load.tasks[i].curr_start_time = 0;
                system_load.tasks[i].tcb = tcb;
                system_load.tasks[i].valid = true;
                system_load.total_count++;
                break;
            }
        }
    }
}

void sched_note_stop(FAR struct tcb_s *tcb)
{
    int i;

    if (system_load.initialized) {
        for (i = 1; i < CONFIG_MAX_TASKS; i++) {
            if (system_load.tasks[i].tcb != 0 && system_load.tasks[i].tcb->pid == tcb->pid) {
                /* mark slot as fee */
                system_load.tasks[i].valid = false;
                system_load.tasks[i].total_runtime = 0;
                system_load.tasks[i].curr_start_time = 0;
                system_load.tasks[i].tcb = NULL;
                system_load.total_count--;
                break;
            }
        }
    }
}

void sched_note_suspend(FAR struct tcb_s *tcb)
{

    if (system_load.initialized) {
        uint64_t new_time = hrt_absolute_time();

        for (int i = 0; i < CONFIG_MAX_TASKS; i++) {
            /* Task ending its current scheduling run */
            if (system_load.tasks[i].valid && system_load.tasks[i].tcb != 0 && system_load.tasks[i].tcb->pid == tcb->pid) {
                system_load.tasks[i].total_runtime += new_time - system_load.tasks[i].curr_start_time;
                break;
            }
        }
    }
}

void sched_note_resume(FAR struct tcb_s *tcb)
{

    if (system_load.initialized) {
        uint64_t new_time = hrt_absolute_time();

        for (int i = 0; i < CONFIG_MAX_TASKS; i++) {
            if (system_load.tasks[i].valid && system_load.tasks[i].tcb->pid == tcb->pid) {
                // curr_start_time is accessed from an IRQ handler (in logger), so we need
                // to make the update atomic
                irqstate_t irq_state = px4_enter_critical_section();
                system_load.tasks[i].curr_start_time = new_time;
                px4_leave_critical_section(irq_state);
                break;
            }
        }
    }

}

#else
__EXPORT struct system_load_s system_load;
#endif
#endif /* CONFIG_SCHED_INSTRUMENTATION */