linux/tools/perf/bench/syscall.c
Tiezhu Yang ece7f7c050 perf bench syscall: Add fork syscall benchmark
This is a follow up patch for the execve bench which is actually
fork + execve, it makes sense to add the fork syscall benchmark
to compare the execve part precisely.

Some archs have no __NR_fork definition which is used only as a
check condition to call test_fork(), let us just define it as -1
to avoid build error.

Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: loongson-kernel@lists.loongnix.cn
Link: https://lore.kernel.org/r/1679381821-22736-1-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-04-04 09:39:55 -03:00

185 lines
3.6 KiB
C

/*
*
* syscall.c
*
* syscall: Benchmark for system call performance
*/
#include "../perf.h"
#include "../util/util.h"
#include <subcmd/parse-options.h>
#include "../builtin.h"
#include "bench.h"
#include <stdio.h>
#include <sys/time.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdlib.h>
#ifndef __NR_fork
#define __NR_fork -1
#endif
#define LOOPS_DEFAULT 10000000
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_syscall_usage[] = {
"perf bench syscall <options>",
NULL
};
static void test_fork(void)
{
pid_t pid = fork();
if (pid < 0) {
fprintf(stderr, "fork failed\n");
exit(1);
} else if (pid == 0) {
exit(0);
} else {
if (waitpid(pid, NULL, 0) < 0) {
fprintf(stderr, "waitpid failed\n");
exit(1);
}
}
}
static void test_execve(void)
{
const char *pathname = "/bin/true";
char *const argv[] = { (char *)pathname, NULL };
pid_t pid = fork();
if (pid < 0) {
fprintf(stderr, "fork failed\n");
exit(1);
} else if (pid == 0) {
execve(pathname, argv, NULL);
fprintf(stderr, "execve /bin/true failed\n");
exit(1);
} else {
if (waitpid(pid, NULL, 0) < 0) {
fprintf(stderr, "waitpid failed\n");
exit(1);
}
}
}
static int bench_syscall_common(int argc, const char **argv, int syscall)
{
struct timeval start, stop, diff;
unsigned long long result_usec = 0;
const char *name = NULL;
int i;
argc = parse_options(argc, argv, options, bench_syscall_usage, 0);
gettimeofday(&start, NULL);
for (i = 0; i < loops; i++) {
switch (syscall) {
case __NR_getppid:
getppid();
break;
case __NR_getpgid:
getpgid(0);
break;
case __NR_fork:
test_fork();
/* Only loop 10000 times to save time */
if (i == 10000)
loops = 10000;
break;
case __NR_execve:
test_execve();
/* Only loop 10000 times to save time */
if (i == 10000)
loops = 10000;
break;
default:
break;
}
}
gettimeofday(&stop, NULL);
timersub(&stop, &start, &diff);
switch (syscall) {
case __NR_getppid:
name = "getppid()";
break;
case __NR_getpgid:
name = "getpgid()";
break;
case __NR_fork:
name = "fork()";
break;
case __NR_execve:
name = "execve()";
break;
default:
break;
}
switch (bench_format) {
case BENCH_FORMAT_DEFAULT:
printf("# Executed %'d %s calls\n", loops, name);
result_usec = diff.tv_sec * 1000000;
result_usec += diff.tv_usec;
printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
(unsigned long) diff.tv_sec,
(unsigned long) (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",
(unsigned long) diff.tv_sec,
(unsigned long) (diff.tv_usec / 1000));
break;
default:
/* reaching here is something disaster */
fprintf(stderr, "Unknown format:%d\n", bench_format);
exit(1);
break;
}
return 0;
}
int bench_syscall_basic(int argc, const char **argv)
{
return bench_syscall_common(argc, argv, __NR_getppid);
}
int bench_syscall_getpgid(int argc, const char **argv)
{
return bench_syscall_common(argc, argv, __NR_getpgid);
}
int bench_syscall_fork(int argc, const char **argv)
{
return bench_syscall_common(argc, argv, __NR_fork);
}
int bench_syscall_execve(int argc, const char **argv)
{
return bench_syscall_common(argc, argv, __NR_execve);
}