// SPDX-License-Identifier: GPL-2.0
/*
*
* sched-pipe.c
*
* pipe: Benchmark for pipe()
*
* Based on pipe-test-1m.c by Ingo Molnar <[email protected]>
* http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c
* Ported to perf by Hitoshi Mitake <[email protected]>
*/
#include <subcmd/parse-options.h>
#include <api/fs/fs.h>
#include "bench.h"
#include "util/cgroup.h"
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/wait.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <assert.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include <linux/time64.h>
#include <pthread.h>
struct thread_data {
int nr;
int pipe_read;
int pipe_write;
bool cgroup_failed;
pthread_t pthread;
};
#define LOOPS_DEFAULT 1000000
static int loops = LOOPS_DEFAULT;
/* Use processes by default: */
static bool threaded;
static char *cgrp_names[2];
static struct cgroup *cgrps[2];
static int parse_two_cgroups(const struct option *opt __maybe_unused,
const char *str, int unset __maybe_unused)
{
char *p = strdup(str);
char *q;
int ret = -1;
if (p == NULL) {
fprintf(stderr, "memory allocation failure\n");
return -1;
}
q = strchr(p, ',');
if (q == NULL) {
fprintf(stderr, "it should have two cgroup names: %s\n", p);
goto out;
}
*q = '\0';
cgrp_names[0] = strdup(p);
cgrp_names[1] = strdup(q + 1);
if (cgrp_names[0] == NULL || cgrp_names[1] == NULL) {
fprintf(stderr, "memory allocation failure\n");
goto out;
}
ret = 0;
out:
free(p);
return ret;
}
static const struct option options[] = {
OPT_INTEGER('l', "loop", &loops, "Specify number of loops"),
OPT_BOOLEAN('T', "threaded", &threaded, "Specify threads/process based task setup"),
OPT_CALLBACK('G', "cgroups", NULL, "SEND,RECV",
"Put sender and receivers in given cgroups",
parse_two_cgroups),
OPT_END()
};
static const char * const bench_sched_pipe_usage[] = {
"perf bench sched pipe <options>",
NULL
};
static int enter_cgroup(int nr)
{
char buf[32];
int fd, len, ret;
int saved_errno;
struct cgroup *cgrp;
pid_t pid;
if (cgrp_names[nr] == NULL)
return 0;
if (cgrps[nr] == NULL) {
cgrps[nr] = cgroup__new(cgrp_names[nr], /*do_open=*/true);
if (cgrps[nr] == NULL)
goto err;
}
cgrp = cgrps[nr];
if (threaded)
pid = syscall(__NR_gettid);
else
pid = getpid();
snprintf(buf, sizeof(buf), "%d\n", pid);
len = strlen(buf);
/* try cgroup v2 interface first */
if (threaded)
fd = openat(cgrp->fd, "cgroup.threads", O_WRONLY);
else
fd = openat(cgrp->fd, "cgroup.procs", O_WRONLY);
/* try cgroup v1 if failed */
if (fd < 0 && errno == ENOENT)
fd = openat(cgrp->fd, "tasks", O_WRONLY);
if (fd < 0)
goto err;
ret = write(fd, buf, len);
close(fd);
if (ret != len) {
printf("Cannot enter to cgroup: %s\n", cgrp->name);
return -1;
}
return 0;
err:
saved_errno = errno;
printf("Failed to open cgroup file in %s\n", cgrp_names[nr]);
if (saved_errno == ENOENT) {
char mnt[PATH_MAX];
if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event") == 0)
printf(" Hint: create the cgroup first, like 'mkdir %s/%s'\n",
mnt, cgrp_names[nr]);
} else if (saved_errno == EACCES && geteuid() > 0) {
printf(" Hint: try to run as root\n");
}
return -1;
}
static void exit_cgroup(int nr)
{
cgroup__put(cgrps[nr]);
free(cgrp_names[nr]);
}
static void *worker_thread(void *__tdata)
{
struct thread_data *td = __tdata;
int m = 0, i;
int ret;
ret = enter_cgroup(td->nr);
if (ret < 0) {
td->cgroup_failed = true;
return NULL;
}
for (i = 0; i < loops; i++) {
if (!td->nr) {
ret = read(td->pipe_read, &m, sizeof(int));
BUG_ON(ret != sizeof(int));
ret = write(td->pipe_write, &m, sizeof(int));
BUG_ON(ret != sizeof(int));
} else {
ret = write(td->pipe_write, &m, sizeof(int));
BUG_ON(ret != sizeof(int));
ret = read(td->pipe_read, &m, sizeof(int));
BUG_ON(ret != sizeof(int));
}
}
return NULL;
}
int bench_sched_pipe(int argc, const char **argv)
{
struct thread_data threads[2] = {};
struct thread_data *td;
int pipe_1[2], pipe_2[2];
struct timeval start, stop, diff;
unsigned long long result_usec = 0;
int nr_threads = 2;
int t;
/*
* why does "ret" exist?
* discarding returned value of read(), write()
* causes error in building environment for perf
*/
int __maybe_unused ret, wait_stat;
pid_t pid, retpid __maybe_unused;
argc = parse_options(argc, argv, options, bench_sched_pipe_usage, 0);
BUG_ON(pipe(pipe_1));
BUG_ON(pipe(pipe_2));
gettimeofday(&start, NULL);
for (t = 0; t < nr_threads; t++) {
td = threads + t;
td->nr = t;
if (t == 0) {
td->pipe_read = pipe_1[0];
td->pipe_write = pipe_2[1];
} else {
td->pipe_write = pipe_1[1];
td->pipe_read = pipe_2[0];
}
}
if (threaded) {
for (t = 0; t < nr_threads; t++) {
td = threads + t;
ret = pthread_create(&td->pthread, NULL, worker_thread, td);
BUG_ON(ret);
}
for (t = 0; t < nr_threads; t++) {
td = threads + t;
ret = pthread_join(td->pthread, NULL);
BUG_ON(ret);
}
} else {
pid = fork();
assert(pid >= 0);
if (!pid) {
worker_thread(threads + 0);
exit(0);
} else {
worker_thread(threads + 1);
}
retpid = waitpid(pid, &wait_stat, 0);
assert((retpid == pid) && WIFEXITED(wait_stat));
}
gettimeofday(&stop, NULL);
timersub(&stop, &start, &diff);
exit_cgroup(0);
exit_cgroup(1);
if (threads[0].cgroup_failed || threads[1].cgroup_failed)
return 0;
switch (bench_format) {
case BENCH_FORMAT_DEFAULT:
printf("# Executed %d pipe operations between two %s\n\n",
loops, threaded ? "threads" : "processes");
result_usec = diff.tv_sec * USEC_PER_SEC;
result_usec += diff.tv_usec;
printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
(unsigned long) diff.tv_sec,
(unsigned long) (diff.tv_usec / USEC_PER_MSEC));
printf(" %14lf usecs/op\n",
(double)result_usec / (double)loops);
printf(" %14d ops/sec\n",
(int)((double)loops /
((double)result_usec / (double)USEC_PER_SEC)));
break;
case BENCH_FORMAT_SIMPLE:
printf("%lu.%03lu\n",
(unsigned long) diff.tv_sec,
(unsigned long) (diff.tv_usec / USEC_PER_MSEC));
break;
default:
/* reaching here is something disaster */
fprintf(stderr, "Unknown format:%d\n", bench_format);
exit(1);
break;
}
return 0;
}
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