/*
* Copyright (c) 2018 Google, Inc.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*
* A DL task runs. Its execution pattern is checked to see that the constraints
* it has been given (runtime, period, deadline) are satisfied.
*/
#define _GNU_SOURCE
#include <errno.h>
#include <pthread.h>
#include <sched.h>
#include <semaphore.h>
#include <time.h>
#include "tst_test.h"
#include "tst_safe_file_ops.h"
#include "tst_safe_pthread.h"
#include "lapi/syscalls.h"
#include "lapi/sched.h"
#include "trace_parse.h"
#include "util.h"
#define TRACE_EVENTS "sched_switch"
static int dl_task_tid;
/*
* It is not possible to restrict CPU affinity on SCHED_DEADLINE tasks, so we do
* not force the CFS and DL tasks to be on the same CPU in this test. CPUsets
* can be used to do this, perhaps implement that later.
*/
static void *dl_fn(void *arg LTP_ATTRIBUTE_UNUSED)
{
struct sched_attr attr;
struct timespec ts;
uint64_t now_usec, end_usec;
attr.size = sizeof(attr);
attr.sched_flags = 0;
attr.sched_nice = 0;
attr.sched_priority = 0;
attr.sched_policy = SCHED_DEADLINE;
attr.sched_runtime = 5000000;
attr.sched_period = 20000000;
attr.sched_deadline = 10000000;
SAFE_FILE_PRINTF(TRACING_DIR "trace_marker", "DL START");
ERROR_CHECK(sched_setattr(0, &attr, 0));
dl_task_tid = gettid();
if (clock_gettime(CLOCK_MONOTONIC, &ts)) {
printf("clock_gettime() reported an error\n");
return NULL;
}
now_usec = (ts.tv_sec) * USEC_PER_SEC + (ts.tv_nsec / 1000);
end_usec = now_usec + 3 * USEC_PER_SEC;
while (now_usec < end_usec) {
/* Run for 5ms */
burn(5000, 0);
/* Wait until next 20ms boundary. sched_yield() for DL tasks
* throttles the task until its next period. */
sched_yield();
if (clock_gettime(CLOCK_MONOTONIC, &ts)) {
printf("clock_gettime() reported an error\n");
return NULL;
}
now_usec = (ts.tv_sec) * USEC_PER_SEC + (ts.tv_nsec / 1000);
}
return NULL;
}
static int parse_results(void)
{
int i;
unsigned long long next_period_ts_us = 0;
unsigned long long next_deadline_ts_us = 0;
unsigned long long start_ts_us = 0;
unsigned long long period_exec_time_us = 0;
int periods_parsed = 0;
for (i = 0; i < num_trace_records; i++) {
if (trace[i].event_type == TRACE_RECORD_SCHED_SWITCH) {
struct trace_sched_switch *t = trace[i].event_data;
if (t->prev_pid == dl_task_tid) {
unsigned long long end_ts_us;
if (!start_ts_us) {
printf("Trace parse error, "
"start_ts_us = 0\n");
return -1;
}
if (TS_TO_USEC(trace[i].ts) >
next_period_ts_us) {
printf("Task ran past end of "
"period!\n");
return -1;
}
end_ts_us = TS_TO_USEC(trace[i].ts);
if (end_ts_us > next_deadline_ts_us)
end_ts_us = next_deadline_ts_us;
if (start_ts_us > next_deadline_ts_us)
start_ts_us = next_deadline_ts_us;
period_exec_time_us +=
(end_ts_us - start_ts_us);
start_ts_us = 0;
}
}
if (next_period_ts_us &&
TS_TO_USEC(trace[i].ts) > next_period_ts_us) {
if (start_ts_us) {
printf("Task was running across period boundary!\n");
return -1;
}
if (period_exec_time_us < 5000) {
printf("Missed deadline at %llu!\n",
next_deadline_ts_us);
return -1;
}
periods_parsed++;
next_deadline_ts_us += 20000;
next_period_ts_us += 20000;
}
if (trace[i].event_type == TRACE_RECORD_SCHED_SWITCH) {
struct trace_sched_switch *t = trace[i].event_data;
if (t->next_pid == dl_task_tid) {
if (start_ts_us) {
printf("Trace parse error, "
"start_ts_us != 0\n");
return -1;
}
start_ts_us = TS_TO_USEC(trace[i].ts);
if (!next_period_ts_us) {
/*
* Initialize period and deadline the
* first time the DL task runs.
*/
next_period_ts_us = start_ts_us + 20000;
next_deadline_ts_us = start_ts_us +
10000;
}
}
}
}
if (periods_parsed >= 149)
printf("%d periods parsed successfully.\n", periods_parsed);
else
printf("Only %d periods parsed successfully.\n",
periods_parsed);
return 0;
}
static void run(void)
{
pthread_t dl_thread;
pthread_attr_t dl_thread_attrs;
struct sched_param dl_thread_sched_params;
ERROR_CHECK(pthread_attr_init(&dl_thread_attrs));
ERROR_CHECK(pthread_attr_setinheritsched(&dl_thread_attrs,
PTHREAD_EXPLICIT_SCHED));
ERROR_CHECK(pthread_attr_setschedpolicy(&dl_thread_attrs,
SCHED_FIFO));
dl_thread_sched_params.sched_priority = 80;
ERROR_CHECK(pthread_attr_setschedparam(&dl_thread_attrs,
&dl_thread_sched_params));
/* configure and enable tracing */
SAFE_FILE_PRINTF(TRACING_DIR "tracing_on", "0");
SAFE_FILE_PRINTF(TRACING_DIR "buffer_size_kb", "16384");
SAFE_FILE_PRINTF(TRACING_DIR "set_event", TRACE_EVENTS);
SAFE_FILE_PRINTF(TRACING_DIR "trace", "\n");
SAFE_FILE_PRINTF(TRACING_DIR "tracing_on", "1");
SAFE_PTHREAD_CREATE(&dl_thread, NULL, dl_fn, NULL);
SAFE_PTHREAD_JOIN(dl_thread, NULL);
/* disable tracing */
SAFE_FILE_PRINTF(TRACING_DIR "tracing_on", "0");
LOAD_TRACE();
if (parse_results())
tst_res(TFAIL, "DL task did not execute as expected.\n");
else
tst_res(TPASS, "DL task ran as expected.\n");
}
static struct tst_test test = {
.test_all = run,
.cleanup = trace_cleanup,
};