zephyr/kernel/usage.c
Peter Mitsis 5deaffb2ee kernel: update z_sched_thread_usage()
This commit does two things to the z_sched_thread_usage(). First,
it updates the API so that it accepts a pointer to the runtime
stats instead of simply returning the usage cycles. This gives it
the flexibility to retrieve additional statistics in the future.

Second, the runtime stats are only updated if the specified thread
is the current thread running on the current core.

Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>
2022-01-10 10:38:06 -05:00

104 lines
2.1 KiB
C

/*
* Copyright (c) 2018 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <kernel.h>
#include <timing/timing.h>
#include <ksched.h>
#include <spinlock.h>
/* Need one of these for this to work */
#if !defined(CONFIG_USE_SWITCH) && !defined(CONFIG_INSTRUMENT_THREAD_SWITCHING)
#error "No data backend configured for CONFIG_SCHED_THREAD_USAGE"
#endif
static struct k_spinlock usage_lock;
static uint32_t usage_now(void)
{
uint32_t now;
#ifdef CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS
now = (uint32_t)timing_counter_get();
#else
now = k_cycle_get_32();
#endif
/* Edge case: we use a zero as a null ("stop() already called") */
return (now == 0) ? 1 : now;
}
void z_sched_usage_start(struct k_thread *thread)
{
/* One write through a volatile pointer doesn't require
* synchronization as long as _usage() treats it as volatile
* (we can't race with _stop() by design).
*/
_current_cpu->usage0 = usage_now();
}
void z_sched_usage_stop(void)
{
k_spinlock_key_t k = k_spin_lock(&usage_lock);
uint32_t u0 = _current_cpu->usage0;
if (u0 != 0) {
uint32_t dt = usage_now() - u0;
#ifdef CONFIG_SCHED_THREAD_USAGE_ALL
if (z_is_idle_thread_object(_current)) {
_kernel.idle_thread_usage += dt;
} else {
_kernel.all_thread_usage += dt;
}
#endif
_current->base.usage += dt;
}
_current_cpu->usage0 = 0;
k_spin_unlock(&usage_lock, k);
}
void z_sched_thread_usage(struct k_thread *thread,
struct k_thread_runtime_stats *stats)
{
uint32_t u0;
uint32_t now;
struct _cpu *cpu;
k_spinlock_key_t key;
cpu = _current_cpu;
key = k_spin_lock(&usage_lock);
u0 = cpu->usage0;
now = usage_now();
if ((u0 != 0) && (thread == cpu->current)) {
uint32_t dt = now - u0;
/*
* Update the thread's usage stats if it is the current thread
* running on the current core.
*/
#ifdef CONFIG_SCHED_THREAD_USAGE_ALL
if (z_is_idle_thread_object(thread)) {
_kernel.idle_thread_usage += dt;
} else {
_kernel.all_thread_usage += dt;
}
#endif
thread->base.usage += dt;
cpu->usage0 = now;
}
stats->execution_cycles = thread->base.usage;
k_spin_unlock(&usage_lock, key);
}