492 lines
8.5 KiB
C
492 lines
8.5 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-or-later
|
||
|
|
/*
|
||
|
|
* Context switch microbenchmark.
|
||
|
|
*
|
||
|
|
* Copyright (C) 2015 Anton Blanchard <anton@au.ibm.com>, IBM
|
||
|
|
*/
|
||
|
|
|
||
|
|
#define _GNU_SOURCE
|
||
|
|
#include <errno.h>
|
||
|
|
#include <sched.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <getopt.h>
|
||
|
|
#include <signal.h>
|
||
|
|
#include <assert.h>
|
||
|
|
#include <pthread.h>
|
||
|
|
#include <limits.h>
|
||
|
|
#include <sys/time.h>
|
||
|
|
#include <sys/syscall.h>
|
||
|
|
#include <sys/types.h>
|
||
|
|
#include <sys/shm.h>
|
||
|
|
#include <linux/futex.h>
|
||
|
|
#ifdef __powerpc__
|
||
|
|
#include <altivec.h>
|
||
|
|
#endif
|
||
|
|
#include "utils.h"
|
||
|
|
|
||
|
|
static unsigned int timeout = 30;
|
||
|
|
|
||
|
|
static int touch_vdso;
|
||
|
|
struct timeval tv;
|
||
|
|
|
||
|
|
static int touch_fp = 1;
|
||
|
|
double fp;
|
||
|
|
|
||
|
|
static int touch_vector = 1;
|
||
|
|
vector int a, b, c;
|
||
|
|
|
||
|
|
#ifdef __powerpc__
|
||
|
|
static int touch_altivec = 1;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Note: LTO (Link Time Optimisation) doesn't play well with this function
|
||
|
|
* attribute. Be very careful enabling LTO for this test.
|
||
|
|
*/
|
||
|
|
static void __attribute__((__target__("no-vsx"))) altivec_touch_fn(void)
|
||
|
|
{
|
||
|
|
c = a + b;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
static void touch(void)
|
||
|
|
{
|
||
|
|
if (touch_vdso)
|
||
|
|
gettimeofday(&tv, NULL);
|
||
|
|
|
||
|
|
if (touch_fp)
|
||
|
|
fp += 0.1;
|
||
|
|
|
||
|
|
#ifdef __powerpc__
|
||
|
|
if (touch_altivec)
|
||
|
|
altivec_touch_fn();
|
||
|
|
#endif
|
||
|
|
|
||
|
|
if (touch_vector)
|
||
|
|
c = a + b;
|
||
|
|
|
||
|
|
asm volatile("# %0 %1 %2": : "r"(&tv), "r"(&fp), "r"(&c));
|
||
|
|
}
|
||
|
|
|
||
|
|
static void start_thread_on(void *(*fn)(void *), void *arg, unsigned long cpu)
|
||
|
|
{
|
||
|
|
int rc;
|
||
|
|
pthread_t tid;
|
||
|
|
cpu_set_t cpuset;
|
||
|
|
pthread_attr_t attr;
|
||
|
|
|
||
|
|
CPU_ZERO(&cpuset);
|
||
|
|
CPU_SET(cpu, &cpuset);
|
||
|
|
|
||
|
|
rc = pthread_attr_init(&attr);
|
||
|
|
if (rc) {
|
||
|
|
errno = rc;
|
||
|
|
perror("pthread_attr_init");
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
|
||
|
|
rc = pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &cpuset);
|
||
|
|
if (rc) {
|
||
|
|
errno = rc;
|
||
|
|
perror("pthread_attr_setaffinity_np");
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
|
||
|
|
rc = pthread_create(&tid, &attr, fn, arg);
|
||
|
|
if (rc) {
|
||
|
|
errno = rc;
|
||
|
|
perror("pthread_create");
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static void start_process_on(void *(*fn)(void *), void *arg, unsigned long cpu)
|
||
|
|
{
|
||
|
|
int pid;
|
||
|
|
cpu_set_t cpuset;
|
||
|
|
|
||
|
|
pid = fork();
|
||
|
|
if (pid == -1) {
|
||
|
|
perror("fork");
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (pid)
|
||
|
|
return;
|
||
|
|
|
||
|
|
CPU_ZERO(&cpuset);
|
||
|
|
CPU_SET(cpu, &cpuset);
|
||
|
|
|
||
|
|
if (sched_setaffinity(0, sizeof(cpuset), &cpuset)) {
|
||
|
|
perror("sched_setaffinity");
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
|
||
|
|
fn(arg);
|
||
|
|
|
||
|
|
exit(0);
|
||
|
|
}
|
||
|
|
|
||
|
|
static unsigned long iterations;
|
||
|
|
static unsigned long iterations_prev;
|
||
|
|
|
||
|
|
static void sigalrm_handler(int junk)
|
||
|
|
{
|
||
|
|
unsigned long i = iterations;
|
||
|
|
|
||
|
|
printf("%ld\n", i - iterations_prev);
|
||
|
|
iterations_prev = i;
|
||
|
|
|
||
|
|
if (--timeout == 0)
|
||
|
|
kill(0, SIGUSR1);
|
||
|
|
|
||
|
|
alarm(1);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void sigusr1_handler(int junk)
|
||
|
|
{
|
||
|
|
exit(0);
|
||
|
|
}
|
||
|
|
|
||
|
|
struct actions {
|
||
|
|
void (*setup)(int, int);
|
||
|
|
void *(*thread1)(void *);
|
||
|
|
void *(*thread2)(void *);
|
||
|
|
};
|
||
|
|
|
||
|
|
#define READ 0
|
||
|
|
#define WRITE 1
|
||
|
|
|
||
|
|
static int pipe_fd1[2];
|
||
|
|
static int pipe_fd2[2];
|
||
|
|
|
||
|
|
static void pipe_setup(int cpu1, int cpu2)
|
||
|
|
{
|
||
|
|
if (pipe(pipe_fd1) || pipe(pipe_fd2))
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void *pipe_thread1(void *arg)
|
||
|
|
{
|
||
|
|
signal(SIGALRM, sigalrm_handler);
|
||
|
|
alarm(1);
|
||
|
|
|
||
|
|
while (1) {
|
||
|
|
assert(read(pipe_fd1[READ], &c, 1) == 1);
|
||
|
|
touch();
|
||
|
|
|
||
|
|
assert(write(pipe_fd2[WRITE], &c, 1) == 1);
|
||
|
|
touch();
|
||
|
|
|
||
|
|
iterations += 2;
|
||
|
|
}
|
||
|
|
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void *pipe_thread2(void *arg)
|
||
|
|
{
|
||
|
|
while (1) {
|
||
|
|
assert(write(pipe_fd1[WRITE], &c, 1) == 1);
|
||
|
|
touch();
|
||
|
|
|
||
|
|
assert(read(pipe_fd2[READ], &c, 1) == 1);
|
||
|
|
touch();
|
||
|
|
}
|
||
|
|
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct actions pipe_actions = {
|
||
|
|
.setup = pipe_setup,
|
||
|
|
.thread1 = pipe_thread1,
|
||
|
|
.thread2 = pipe_thread2,
|
||
|
|
};
|
||
|
|
|
||
|
|
static void yield_setup(int cpu1, int cpu2)
|
||
|
|
{
|
||
|
|
if (cpu1 != cpu2) {
|
||
|
|
fprintf(stderr, "Both threads must be on the same CPU for yield test\n");
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static void *yield_thread1(void *arg)
|
||
|
|
{
|
||
|
|
signal(SIGALRM, sigalrm_handler);
|
||
|
|
alarm(1);
|
||
|
|
|
||
|
|
while (1) {
|
||
|
|
sched_yield();
|
||
|
|
touch();
|
||
|
|
|
||
|
|
iterations += 2;
|
||
|
|
}
|
||
|
|
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void *yield_thread2(void *arg)
|
||
|
|
{
|
||
|
|
while (1) {
|
||
|
|
sched_yield();
|
||
|
|
touch();
|
||
|
|
}
|
||
|
|
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct actions yield_actions = {
|
||
|
|
.setup = yield_setup,
|
||
|
|
.thread1 = yield_thread1,
|
||
|
|
.thread2 = yield_thread2,
|
||
|
|
};
|
||
|
|
|
||
|
|
static long sys_futex(void *addr1, int op, int val1, struct timespec *timeout,
|
||
|
|
void *addr2, int val3)
|
||
|
|
{
|
||
|
|
return syscall(SYS_futex, addr1, op, val1, timeout, addr2, val3);
|
||
|
|
}
|
||
|
|
|
||
|
|
static unsigned long cmpxchg(unsigned long *p, unsigned long expected,
|
||
|
|
unsigned long desired)
|
||
|
|
{
|
||
|
|
unsigned long exp = expected;
|
||
|
|
|
||
|
|
__atomic_compare_exchange_n(p, &exp, desired, 0,
|
||
|
|
__ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
|
||
|
|
return exp;
|
||
|
|
}
|
||
|
|
|
||
|
|
static unsigned long xchg(unsigned long *p, unsigned long val)
|
||
|
|
{
|
||
|
|
return __atomic_exchange_n(p, val, __ATOMIC_SEQ_CST);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int processes;
|
||
|
|
|
||
|
|
static int mutex_lock(unsigned long *m)
|
||
|
|
{
|
||
|
|
int c;
|
||
|
|
int flags = FUTEX_WAIT;
|
||
|
|
if (!processes)
|
||
|
|
flags |= FUTEX_PRIVATE_FLAG;
|
||
|
|
|
||
|
|
c = cmpxchg(m, 0, 1);
|
||
|
|
if (!c)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (c == 1)
|
||
|
|
c = xchg(m, 2);
|
||
|
|
|
||
|
|
while (c) {
|
||
|
|
sys_futex(m, flags, 2, NULL, NULL, 0);
|
||
|
|
c = xchg(m, 2);
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int mutex_unlock(unsigned long *m)
|
||
|
|
{
|
||
|
|
int flags = FUTEX_WAKE;
|
||
|
|
if (!processes)
|
||
|
|
flags |= FUTEX_PRIVATE_FLAG;
|
||
|
|
|
||
|
|
if (*m == 2)
|
||
|
|
*m = 0;
|
||
|
|
else if (xchg(m, 0) == 1)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
sys_futex(m, flags, 1, NULL, NULL, 0);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static unsigned long *m1, *m2;
|
||
|
|
|
||
|
|
static void futex_setup(int cpu1, int cpu2)
|
||
|
|
{
|
||
|
|
if (!processes) {
|
||
|
|
static unsigned long _m1, _m2;
|
||
|
|
m1 = &_m1;
|
||
|
|
m2 = &_m2;
|
||
|
|
} else {
|
||
|
|
int shmid;
|
||
|
|
void *shmaddr;
|
||
|
|
|
||
|
|
shmid = shmget(IPC_PRIVATE, getpagesize(), SHM_R | SHM_W);
|
||
|
|
if (shmid < 0) {
|
||
|
|
perror("shmget");
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
|
||
|
|
shmaddr = shmat(shmid, NULL, 0);
|
||
|
|
if (shmaddr == (char *)-1) {
|
||
|
|
perror("shmat");
|
||
|
|
shmctl(shmid, IPC_RMID, NULL);
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
|
||
|
|
shmctl(shmid, IPC_RMID, NULL);
|
||
|
|
|
||
|
|
m1 = shmaddr;
|
||
|
|
m2 = shmaddr + sizeof(*m1);
|
||
|
|
}
|
||
|
|
|
||
|
|
*m1 = 0;
|
||
|
|
*m2 = 0;
|
||
|
|
|
||
|
|
mutex_lock(m1);
|
||
|
|
mutex_lock(m2);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void *futex_thread1(void *arg)
|
||
|
|
{
|
||
|
|
signal(SIGALRM, sigalrm_handler);
|
||
|
|
alarm(1);
|
||
|
|
|
||
|
|
while (1) {
|
||
|
|
mutex_lock(m2);
|
||
|
|
mutex_unlock(m1);
|
||
|
|
|
||
|
|
iterations += 2;
|
||
|
|
}
|
||
|
|
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void *futex_thread2(void *arg)
|
||
|
|
{
|
||
|
|
while (1) {
|
||
|
|
mutex_unlock(m2);
|
||
|
|
mutex_lock(m1);
|
||
|
|
}
|
||
|
|
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct actions futex_actions = {
|
||
|
|
.setup = futex_setup,
|
||
|
|
.thread1 = futex_thread1,
|
||
|
|
.thread2 = futex_thread2,
|
||
|
|
};
|
||
|
|
|
||
|
|
static struct option options[] = {
|
||
|
|
{ "test", required_argument, 0, 't' },
|
||
|
|
{ "process", no_argument, &processes, 1 },
|
||
|
|
{ "timeout", required_argument, 0, 's' },
|
||
|
|
{ "vdso", no_argument, &touch_vdso, 1 },
|
||
|
|
{ "no-fp", no_argument, &touch_fp, 0 },
|
||
|
|
#ifdef __powerpc__
|
||
|
|
{ "no-altivec", no_argument, &touch_altivec, 0 },
|
||
|
|
#endif
|
||
|
|
{ "no-vector", no_argument, &touch_vector, 0 },
|
||
|
|
{ 0, },
|
||
|
|
};
|
||
|
|
|
||
|
|
static void usage(void)
|
||
|
|
{
|
||
|
|
fprintf(stderr, "Usage: context_switch2 <options> CPU1 CPU2\n\n");
|
||
|
|
fprintf(stderr, "\t\t--test=X\tpipe, futex or yield (default)\n");
|
||
|
|
fprintf(stderr, "\t\t--process\tUse processes (default threads)\n");
|
||
|
|
fprintf(stderr, "\t\t--timeout=X\tDuration in seconds to run (default 30)\n");
|
||
|
|
fprintf(stderr, "\t\t--vdso\t\ttouch VDSO\n");
|
||
|
|
fprintf(stderr, "\t\t--no-fp\t\tDon't touch FP\n");
|
||
|
|
#ifdef __powerpc__
|
||
|
|
fprintf(stderr, "\t\t--no-altivec\tDon't touch altivec\n");
|
||
|
|
#endif
|
||
|
|
fprintf(stderr, "\t\t--no-vector\tDon't touch vector\n");
|
||
|
|
}
|
||
|
|
|
||
|
|
int main(int argc, char *argv[])
|
||
|
|
{
|
||
|
|
signed char c;
|
||
|
|
struct actions *actions = &yield_actions;
|
||
|
|
int cpu1;
|
||
|
|
int cpu2;
|
||
|
|
static void (*start_fn)(void *(*fn)(void *), void *arg, unsigned long cpu);
|
||
|
|
|
||
|
|
while (1) {
|
||
|
|
int option_index = 0;
|
||
|
|
|
||
|
|
c = getopt_long(argc, argv, "", options, &option_index);
|
||
|
|
|
||
|
|
if (c == -1)
|
||
|
|
break;
|
||
|
|
|
||
|
|
switch (c) {
|
||
|
|
case 0:
|
||
|
|
if (options[option_index].flag != 0)
|
||
|
|
break;
|
||
|
|
|
||
|
|
usage();
|
||
|
|
exit(1);
|
||
|
|
break;
|
||
|
|
|
||
|
|
case 't':
|
||
|
|
if (!strcmp(optarg, "pipe")) {
|
||
|
|
actions = &pipe_actions;
|
||
|
|
} else if (!strcmp(optarg, "yield")) {
|
||
|
|
actions = &yield_actions;
|
||
|
|
} else if (!strcmp(optarg, "futex")) {
|
||
|
|
actions = &futex_actions;
|
||
|
|
} else {
|
||
|
|
usage();
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
case 's':
|
||
|
|
timeout = atoi(optarg);
|
||
|
|
break;
|
||
|
|
|
||
|
|
default:
|
||
|
|
usage();
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (processes)
|
||
|
|
start_fn = start_process_on;
|
||
|
|
else
|
||
|
|
start_fn = start_thread_on;
|
||
|
|
|
||
|
|
if (((argc - optind) != 2)) {
|
||
|
|
cpu1 = cpu2 = pick_online_cpu();
|
||
|
|
} else {
|
||
|
|
cpu1 = atoi(argv[optind++]);
|
||
|
|
cpu2 = atoi(argv[optind++]);
|
||
|
|
}
|
||
|
|
|
||
|
|
printf("Using %s with ", processes ? "processes" : "threads");
|
||
|
|
|
||
|
|
if (actions == &pipe_actions)
|
||
|
|
printf("pipe");
|
||
|
|
else if (actions == &yield_actions)
|
||
|
|
printf("yield");
|
||
|
|
else
|
||
|
|
printf("futex");
|
||
|
|
|
||
|
|
printf(" on cpus %d/%d touching FP:%s altivec:%s vector:%s vdso:%s\n",
|
||
|
|
cpu1, cpu2, touch_fp ? "yes" : "no", touch_altivec ? "yes" : "no",
|
||
|
|
touch_vector ? "yes" : "no", touch_vdso ? "yes" : "no");
|
||
|
|
|
||
|
|
/* Create a new process group so we can signal everyone for exit */
|
||
|
|
setpgid(getpid(), getpid());
|
||
|
|
|
||
|
|
signal(SIGUSR1, sigusr1_handler);
|
||
|
|
|
||
|
|
actions->setup(cpu1, cpu2);
|
||
|
|
|
||
|
|
start_fn(actions->thread1, NULL, cpu1);
|
||
|
|
start_fn(actions->thread2, NULL, cpu2);
|
||
|
|
|
||
|
|
while (1)
|
||
|
|
sleep(3600);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|