/
steal_budget.c
272 lines (239 loc) · 7.04 KB
/
steal_budget.c
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#define _GNU_SOURCE
#include <sched.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <pthread.h>
#include <math.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include "rt-app_utils.h"
#include "libdl/dl_syscalls.h"
#define NSEC_PER_MSEC 1000000U
#define NSEC_PER_SEC 1000000000U
#define RTIME_URUN 90
#define NRUN 5
#define MAX_THREADS 2
#define gettid() syscall(__NR_gettid)
int trace_fd = -1;
int marker_fd = -1;
int bwi_enabled = 0;
pthread_mutex_t my_mutex;
pthread_mutexattr_t my_mutex_attr;
struct timespec
nsec_to_timespec(__u64 *nsec)
{
struct timespec ts;
ts.tv_sec = *nsec / NSEC_PER_SEC;
ts.tv_nsec = (*nsec % NSEC_PER_SEC);
return ts;
}
void sighandler()
{
ftrace_write(marker_fd, "main killed!\n");
write(trace_fd, "0", 1);
close(trace_fd);
close(marker_fd);
exit(-1);
}
static inline busywait(__u64 len)
{
struct timespec t_len, t_now, t_exec, t_step;
__u64 real_exec = (len / 100) * RTIME_URUN;
t_len = nsec_to_timespec(&real_exec);
clock_gettime(CLOCK_THREAD_CPUTIME_ID, &t_now);
t_exec = timespec_add(&t_now, &t_len);
while (1) {
clock_gettime(CLOCK_THREAD_CPUTIME_ID, &t_step);
if (!timespec_lower(&t_step, &t_exec))
break;
}
}
void *t_1(void *thread_params) {
struct sched_param2 dl_params;
struct timespec t_next, t_period, t_start, t_stop, ran_for,
t_now, t_crit, t_exec;
long tid = gettid();
int retval, i;
cpu_set_t mask;
__u64 crit, run1, runtime, deadline, period;
/*
* t_1 should go in budget overflow while in critical section
*/
run1 = 8U * NSEC_PER_MSEC;
crit = 12U * NSEC_PER_MSEC;
runtime = run1 + crit + (8U * NSEC_PER_MSEC);
deadline = 40U * NSEC_PER_MSEC;
period = deadline;
t_period = nsec_to_timespec(&period);
t_crit = nsec_to_timespec(&crit);
signal(SIGHUP, sighandler);
signal(SIGINT, sighandler);
signal(SIGQUIT, sighandler);
CPU_ZERO(&mask);
CPU_SET(0, &mask);
retval = sched_setaffinity(0, sizeof(mask), &mask);
if (retval) {
fprintf(stderr, "WARNING: could not set task affinity\n");
exit(-1);
}
memset(&dl_params, 0, sizeof(dl_params));
dl_params.sched_priority = 0;
dl_params.sched_runtime = runtime;
dl_params.sched_deadline = deadline;
dl_params.sched_period = period;
ftrace_write(marker_fd, "[thread %ld (t_1)]: setting rt=%llums dl=%llums\n", tid,
runtime/NSEC_PER_MSEC,
deadline/NSEC_PER_MSEC);
retval = sched_setscheduler2(0, SCHED_DEADLINE, &dl_params);
if (retval) {
fprintf(stderr, "WARNING: could not set SCHED_DEADLINE"
" policy!\n");
exit(-1);
}
clock_gettime(CLOCK_MONOTONIC, &t_next);
for (i = 0; i < NRUN; i++) {
ftrace_write(marker_fd, "[t_1] run starts\n");
clock_gettime(CLOCK_MONOTONIC, &t_start);
ftrace_write(marker_fd, "[t_1] exec for %lluns\n", run1);
busywait(run1);
ftrace_write(marker_fd, "[t_1] locks mutex\n");
pthread_mutex_lock(&my_mutex);
ftrace_write(marker_fd, "[t_1] exec for %lluns\n", crit);
busywait(crit);
ftrace_write(marker_fd, "[t_1] unlocks mutex\n");
pthread_mutex_unlock(&my_mutex);
clock_gettime(CLOCK_MONOTONIC, &t_stop);
t_next = timespec_add(&t_next, &t_period);
ran_for = timespec_sub(&t_stop, &t_start);
printf("[thread %ld]: run %d for %lluus\n",
tid,
i,
timespec_to_usec(&ran_for));
ftrace_write(marker_fd, "[t_1] run ends\n");
clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &t_next, NULL);
}
retval = sched_setscheduler2(0, SCHED_OTHER, &dl_params);
if (retval) {
fprintf(stderr, "WARNING: could not set SCHED_OTHER"
"policy!\n");
exit(-1);
}
}
void *t_2(void *thread_params) {
struct sched_param2 dl_params;
struct timespec t_next, t_period, t_start, t_stop, ran_for;
long tid = gettid();
int retval, i;
cpu_set_t mask;
__u64 run1, run2, crit, wait, runtime, deadline, period;
/*
* t_2 should become t_1's proxy and donate its budget when
* needed.
*/
run1 = 4U * NSEC_PER_MSEC;
crit = 12U * NSEC_PER_MSEC;
runtime = run1 + crit - (8U * NSEC_PER_MSEC);
deadline = 48U * NSEC_PER_MSEC;
period = deadline;
t_period = nsec_to_timespec(&period);
signal(SIGHUP, sighandler);
signal(SIGINT, sighandler);
signal(SIGQUIT, sighandler);
CPU_ZERO(&mask);
CPU_SET(1, &mask);
retval = sched_setaffinity(0, sizeof(mask), &mask);
if (retval) {
fprintf(stderr, "WARNING: could not set task affinity\n");
exit(-1);
}
memset(&dl_params, 0, sizeof(dl_params));
dl_params.sched_priority = 0;
dl_params.sched_runtime = runtime;
dl_params.sched_deadline = deadline;
dl_params.sched_period = period;
ftrace_write(marker_fd, "[thread %ld (t_2)]: setting rt=%llums dl=%llums\n", tid,
runtime/NSEC_PER_MSEC,
deadline/NSEC_PER_MSEC);
retval = sched_setscheduler2(0, SCHED_DEADLINE, &dl_params);
if (retval) {
fprintf(stderr, "WARNING: could not set SCHED_DEADLINE"
" policy!\n");
exit(-1);
}
clock_gettime(CLOCK_MONOTONIC, &t_next);
for (i = 0; i < NRUN; i++) {
ftrace_write(marker_fd, "[t_2] run starts\n");
clock_gettime(CLOCK_MONOTONIC, &t_start);
ftrace_write(marker_fd, "[t_2] exec for %lluns\n", run1);
busywait(run1);
ftrace_write(marker_fd, "[t_2] locks mutex\n");
pthread_mutex_lock(&my_mutex);
ftrace_write(marker_fd, "[t_2] exec for %lluns\n", crit);
busywait(crit);
ftrace_write(marker_fd, "[t_2] unlocks mutex\n");
pthread_mutex_unlock(&my_mutex);
clock_gettime(CLOCK_MONOTONIC, &t_stop);
t_next = timespec_add(&t_next, &t_period);
ran_for = timespec_sub(&t_stop, &t_start);
printf("[thread %ld]: run %d for %lluus\n",
tid,
i,
timespec_to_usec(&ran_for));
ftrace_write(marker_fd, "[t_2] run ends\n");
clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &t_next, NULL);
}
retval = sched_setscheduler2(0, SCHED_OTHER, &dl_params);
if (retval) {
fprintf(stderr, "WARNING: could not set SCHED_OTHER"
"policy!\n");
exit(-1);
}
}
int main(int argc, char **argv) {
struct sched_param2 dl_params;
int i, retval;
pthread_t thread[MAX_THREADS];
char *debugfs = "/debug";
char path[256];
long tid = gettid();
if (argc > 1) {
printf("[main] MBWI enabled\n");
bwi_enabled = atoi(argv[1]);
}
printf("main opening trace fds\n");
strcpy(path, debugfs);
strcat(path, "/tracing/tracing_on");
trace_fd = open(path, O_WRONLY);
if (trace_fd < 0) {
printf("can't open trace_fd!\n");
exit(-1);
}
strcpy(path, debugfs);
strcat(path, "/tracing/trace_marker");
marker_fd = open(path, O_WRONLY);
if (marker_fd < 0) {
printf("can't open marker_fd!\n");
exit(-1);
}
/* Initialize mutex variable objects */
pthread_mutexattr_init(&my_mutex_attr);
if (bwi_enabled)
pthread_mutexattr_setprotocol(&my_mutex_attr,
PTHREAD_PRIO_INHERIT);
pthread_mutex_init(&my_mutex, &my_mutex_attr);
printf("[main] creates %d threads\n", MAX_THREADS);
write(trace_fd, "1", 1);
ftrace_write(marker_fd, "[main] creates %d threads\n", MAX_THREADS);
pthread_create(&thread[0], NULL, t_1, NULL);
pthread_create(&thread[1], NULL, t_2, NULL);
for (i = 0; i < MAX_THREADS; i++)
pthread_join(thread[i], NULL);
write(trace_fd, "0", 1);
close(trace_fd);
close(marker_fd);
printf("[main] exits\n");
ftrace_write(marker_fd, "[main] exits\n");
}