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MarekPietanashif
MarekPieta
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nashif
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debug: tracing: Add CPU stats module
Change adds CPU stats module for tracing hooks. Module provides information about percent of CPU usage based on tracing hooks for threads switching in and out, interrupts enters and exits. cpu_stats only distinguishes between idle thread, non idle thread and scheduler. Signed-off-by: Marek Pieta <[email protected]>
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‎include/tracing.h‎

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@@ -29,6 +29,10 @@ void z_sys_trace_thread_switched_out(void);
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#ifdef CONFIG_SEGGER_SYSTEMVIEW
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#include "tracing_sysview.h"
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#elif defined CONFIG_TRACING_CPU_STATS
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#include "tracing_cpu_stats.h"
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#else
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/**

‎subsys/debug/Kconfig‎

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@@ -230,4 +230,29 @@ config OPENOCD_SUPPORT
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OpenOCD to determine the state of running threads. (This option
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selects CONFIG_THREAD_MONITOR, so all of its caveats are implied.)
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config TRACING_CPU_STATS
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bool "Enable CPU usage tracing"
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select THREAD_MONITOR
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select THREAD_STACK_INFO
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select TRACING
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help
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Module provides information about percent of CPU usage based on
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tracing hooks for threads switching in and out, interrupts enters
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and exits (only distinguishes between idle thread, non idle thread
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and scheduler). Use provided API or enable automatical logging to
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get values.
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config TRACING_CPU_STATS_LOG
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bool "Enable current CPU usage logging"
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depends on TRACING_CPU_STATS
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help
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Periodically displays information about CPU usage.
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config TRACING_CPU_STATS_INTERVAL
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int "Logging interval for CPU measurements [ms]"
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default 2000
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depends on TRACING_CPU_STATS_LOG
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help
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Time period of displaying information about CPU usage.
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endmenu

‎subsys/debug/tracing/CMakeLists.txt‎

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@@ -5,3 +5,8 @@ zephyr_sources_ifdef(
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sysview_config.c
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sysview.c
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)
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zephyr_sources_ifdef(
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CONFIG_TRACING_CPU_STATS
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cpu_stats.c
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)

‎subsys/debug/tracing/cpu_stats.c‎

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/*
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* Copyright (c) 2018 Nordic Semiconductor ASA
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <tracing_cpu_stats.h>
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#include <misc/printk.h>
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enum cpu_state {
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CPU_STATE_IDLE,
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CPU_STATE_NON_IDLE,
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CPU_STATE_SCHEDULER
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};
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static enum cpu_state last_cpu_state = CPU_STATE_SCHEDULER;
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static enum cpu_state cpu_state_before_interrupts;
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static u32_t last_time;
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static struct cpu_stats stats_hw_tick;
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static int nested_interrupts;
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static struct k_thread *current_thread;
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#ifndef CONFIG_SMP
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extern k_tid_t const _idle_thread;
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#endif
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static int is_idle_thread(struct k_thread *thread)
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{
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#ifdef CONFIG_SMP
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return thread->base.is_idle;
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#else
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return thread == _idle_thread;
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#endif
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}
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void update_counter(volatile u64_t *cnt)
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{
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u32_t time = k_cycle_get_32();
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if (time >= last_time) {
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(*cnt) += (time - last_time);
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} else {
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(*cnt) += (UINT32_MAX - last_time + 1 + time);
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}
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last_time = time;
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}
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static void cpu_stats_update_counters(void)
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{
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switch (last_cpu_state) {
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case CPU_STATE_IDLE:
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update_counter(&stats_hw_tick.idle);
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break;
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case CPU_STATE_NON_IDLE:
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update_counter(&stats_hw_tick.non_idle);
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break;
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case CPU_STATE_SCHEDULER:
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update_counter(&stats_hw_tick.sched);
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break;
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default:
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/* Invalid CPU state */
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__ASSERT_NO_MSG(false);
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break;
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}
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}
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void cpu_stats_get_ns(struct cpu_stats *cpu_stats_ns)
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{
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int key = irq_lock();
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cpu_stats_update_counters();
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cpu_stats_ns->idle = SYS_CLOCK_HW_CYCLES_TO_NS(stats_hw_tick.idle);
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cpu_stats_ns->non_idle = SYS_CLOCK_HW_CYCLES_TO_NS(
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stats_hw_tick.non_idle);
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cpu_stats_ns->sched = SYS_CLOCK_HW_CYCLES_TO_NS(stats_hw_tick.sched);
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irq_unlock(key);
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}
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u32_t cpu_stats_non_idle_and_sched_get_percent(void)
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{
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int key = irq_lock();
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cpu_stats_update_counters();
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irq_unlock(key);
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return ((stats_hw_tick.non_idle + stats_hw_tick.sched) * 100) /
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(stats_hw_tick.idle + stats_hw_tick.non_idle +
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stats_hw_tick.sched);
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}
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void cpu_stats_reset_counters(void)
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{
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int key = irq_lock();
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stats_hw_tick.idle = 0;
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stats_hw_tick.non_idle = 0;
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stats_hw_tick.sched = 0;
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last_time = k_cycle_get_32();
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irq_unlock(key);
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}
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void sys_trace_thread_switched_in(void)
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{
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int key = irq_lock();
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__ASSERT_NO_MSG(nested_interrupts == 0);
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cpu_stats_update_counters();
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current_thread = k_current_get();
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if (is_idle_thread(current_thread)) {
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last_cpu_state = CPU_STATE_IDLE;
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} else {
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last_cpu_state = CPU_STATE_NON_IDLE;
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}
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irq_unlock(key);
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}
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void sys_trace_thread_switched_out(void)
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{
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int key = irq_lock();
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__ASSERT_NO_MSG(nested_interrupts == 0);
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__ASSERT_NO_MSG(current_thread == k_current_get());
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cpu_stats_update_counters();
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last_cpu_state = CPU_STATE_SCHEDULER;
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irq_unlock(key);
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}
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void sys_trace_isr_enter(void)
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{
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int key = irq_lock();
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if (nested_interrupts == 0) {
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cpu_stats_update_counters();
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cpu_state_before_interrupts = last_cpu_state;
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last_cpu_state = CPU_STATE_NON_IDLE;
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}
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nested_interrupts++;
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irq_unlock(key);
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}
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void sys_trace_isr_exit(void)
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{
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int key = irq_lock();
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nested_interrupts--;
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if (nested_interrupts == 0) {
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cpu_stats_update_counters();
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last_cpu_state = cpu_state_before_interrupts;
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}
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irq_unlock(key);
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}
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void sys_trace_idle(void)
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{
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}
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void z_sys_trace_idle(void)
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{
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sys_trace_idle();
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}
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void z_sys_trace_isr_enter(void)
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{
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sys_trace_isr_enter();
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}
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void z_sys_trace_isr_exit(void)
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{
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sys_trace_isr_exit();
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}
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void z_sys_trace_thread_switched_in(void)
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{
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sys_trace_thread_switched_in();
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}
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void z_sys_trace_thread_switched_out(void)
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{
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sys_trace_thread_switched_out();
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}
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#ifdef CONFIG_TRACING_CPU_STATS_LOG
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static struct k_delayed_work cpu_stats_log;
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static void cpu_stats_display(void)
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{
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printk("CPU usage: %u\n", cpu_stats_non_idle_and_sched_get_percent());
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}
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static void cpu_stats_log_fn(struct k_work *item)
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{
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cpu_stats_display();
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cpu_stats_reset_counters();
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k_delayed_work_submit(&cpu_stats_log,
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CONFIG_TRACING_CPU_STATS_INTERVAL);
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}
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static int cpu_stats_log_init(struct device *dev)
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{
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k_delayed_work_init(&cpu_stats_log, cpu_stats_log_fn);
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k_delayed_work_submit(&cpu_stats_log,
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CONFIG_TRACING_CPU_STATS_INTERVAL);
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return 0;
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}
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SYS_INIT(cpu_stats_log_init, APPLICATION, 0);
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#endif /* CONFIG_TRACING_CPU_STATS_LOG */

‎subsys/debug/tracing/include/tracing_cpu_stats.h‎

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/*
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* Copyright (c) 2018 Nordic Semiconductor ASA
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#ifndef _TRACE_CPU_STATS_H
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#define _TRACE_CPU_STATS_H
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#include <kernel.h>
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#include <kernel_structs.h>
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#include <init.h>
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struct cpu_stats {
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u64_t idle;
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u64_t non_idle;
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u64_t sched;
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};
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void sys_trace_thread_switched_in(void);
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void sys_trace_thread_switched_out(void);
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void sys_trace_isr_enter(void);
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void sys_trace_isr_exit(void);
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void sys_trace_idle(void);
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void cpu_stats_get_ns(struct cpu_stats *cpu_stats_ns);
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u32_t cpu_stats_non_idle_and_sched_get_percent(void);
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void cpu_stats_reset_counters(void);
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#define sys_trace_isr_exit_to_scheduler()
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#define sys_trace_thread_priority_set(thread)
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#define sys_trace_thread_info(thread)
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#define sys_trace_thread_create(thread)
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#define sys_trace_thread_abort(thread)
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#define sys_trace_thread_suspend(thread)
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#define sys_trace_thread_resume(thread)
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#define sys_trace_thread_ready(thread)
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#define sys_trace_thread_pend(thread)
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#define sys_trace_void(id)
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#define sys_trace_end_call(id)
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#endif /* _TRACE_CPU_STATS_H */

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