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/*
*
* sched-pipe.c
*
* pipe: Benchmark for pipe()
*
* Based on pipe-test-1m.c by Ingo Molnar <mingo@redhat.com>
* http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c
* Ported to perf by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
*
*/
#include "../perf.h"
#include "../util/util.h"
#include "../util/parse-options.h"
#include "../builtin.h"
#include "bench.h"
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/wait.h>
#include <linux/unistd.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <sys/time.h>
#include <sys/types.h>
#define LOOPS_DEFAULT 1000000
static int loops = LOOPS_DEFAULT;
static const struct option options[] = {
OPT_INTEGER('l', "loop", &loops,
"Specify number of loops"),
OPT_END()
};
static const char * const bench_sched_pipe_usage[] = {
"perf bench sched pipe <options>",
NULL
};
int bench_sched_pipe(int argc, const char **argv,
const char *prefix __used)
{
int pipe_1[2], pipe_2[2];
int m = 0, i;
struct timeval start, stop, diff;
unsigned long long result_usec = 0;
/*
* why does "ret" exist?
* discarding returned value of read(), write()
* causes error in building environment for perf
*/
int ret, wait_stat;
pid_t pid, retpid;
argc = parse_options(argc, argv, options,
bench_sched_pipe_usage, 0);
assert(!pipe(pipe_1));
assert(!pipe(pipe_2));
pid = fork();
assert(pid >= 0);
gettimeofday(&start, NULL);
if (!pid) {
for (i = 0; i < loops; i++) {
ret = read(pipe_1[0], &m, sizeof(int));
ret = write(pipe_2[1], &m, sizeof(int));
}
} else {
for (i = 0; i < loops; i++) {
ret = write(pipe_1[1], &m, sizeof(int));
ret = read(pipe_2[0], &m, sizeof(int));
}
}
gettimeofday(&stop, NULL);
timersub(&stop, &start, &diff);
if (pid) {
retpid = waitpid(pid, &wait_stat, 0);
assert((retpid == pid) && WIFEXITED(wait_stat));
} else {
exit(0);
}
switch (bench_format) {
case BENCH_FORMAT_DEFAULT:
printf("# Extecuted %d pipe operations between two tasks\n\n",
loops);
result_usec = diff.tv_sec * 1000000;
result_usec += diff.tv_usec;
printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
diff.tv_sec, diff.tv_usec/1000);
printf(" %14lf usecs/op\n",
(double)result_usec / (double)loops);
printf(" %14d ops/sec\n",
(int)((double)loops /
((double)result_usec / (double)1000000)));
break;
case BENCH_FORMAT_SIMPLE:
printf("%lu.%03lu\n",
diff.tv_sec, diff.tv_usec / 1000);
break;
default:
/* reaching here is something disaster */
fprintf(stderr, "Unknown format:%d\n", bench_format);
exit(1);
break;
}
return 0;
}
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