1/*
  2 *
  3 * syscall.c
  4 *
  5 * syscall: Benchmark for system call performance
  6 */
  7#include "../perf.h"
  8#include "../util/util.h"
  9#include <subcmd/parse-options.h>
 10#include "../builtin.h"
 11#include "bench.h"
 12
 13#include <stdio.h>
 14#include <sys/time.h>
 15#include <sys/syscall.h>
 16#include <sys/types.h>
 17#include <sys/wait.h>
 18#include <unistd.h>
 19#include <stdlib.h>
 20
 21#ifndef __NR_fork
 22#define __NR_fork -1
 23#endif
 24
 25#define LOOPS_DEFAULT 10000000
 26static	int loops = LOOPS_DEFAULT;
 27
 28static const struct option options[] = {
 29	OPT_INTEGER('l', "loop",	&loops,		"Specify number of loops"),
 30	OPT_END()
 31};
 32
 33static const char * const bench_syscall_usage[] = {
 34	"perf bench syscall <options>",
 35	NULL
 36};
 37
 38static void test_fork(void)
 39{
 40	pid_t pid = fork();
 41
 42	if (pid < 0) {
 43		fprintf(stderr, "fork failed\n");
 44		exit(1);
 45	} else if (pid == 0) {
 46		exit(0);
 47	} else {
 48		if (waitpid(pid, NULL, 0) < 0) {
 49			fprintf(stderr, "waitpid failed\n");
 50			exit(1);
 51		}
 52	}
 53}
 54
 55static void test_execve(void)
 56{
 57	const char *pathname = "/bin/true";
 58	char *const argv[] = { (char *)pathname, NULL };
 59	pid_t pid = fork();
 60
 61	if (pid < 0) {
 62		fprintf(stderr, "fork failed\n");
 63		exit(1);
 64	} else if (pid == 0) {
 65		execve(pathname, argv, NULL);
 66		fprintf(stderr, "execve /bin/true failed\n");
 67		exit(1);
 68	} else {
 69		if (waitpid(pid, NULL, 0) < 0) {
 70			fprintf(stderr, "waitpid failed\n");
 71			exit(1);
 72		}
 73	}
 74}
 75
 76static int bench_syscall_common(int argc, const char **argv, int syscall)
 77{
 78	struct timeval start, stop, diff;
 79	unsigned long long result_usec = 0;
 80	const char *name = NULL;
 81	int i;
 82
 83	argc = parse_options(argc, argv, options, bench_syscall_usage, 0);
 84
 85	gettimeofday(&start, NULL);
 86
 87	for (i = 0; i < loops; i++) {
 88		switch (syscall) {
 89		case __NR_getppid:
 90			getppid();
 91			break;
 92		case __NR_getpgid:
 93			getpgid(0);
 94			break;
 95		case __NR_fork:
 96			test_fork();
 97			/* Only loop 10000 times to save time */
 98			if (i == 10000)
 99				loops = 10000;
100			break;
101		case __NR_execve:
102			test_execve();
103			/* Only loop 10000 times to save time */
104			if (i == 10000)
105				loops = 10000;
106			break;
107		default:
108			break;
109		}
110	}
111
112	gettimeofday(&stop, NULL);
113	timersub(&stop, &start, &diff);
114
115	switch (syscall) {
116	case __NR_getppid:
117		name = "getppid()";
118		break;
119	case __NR_getpgid:
120		name = "getpgid()";
121		break;
122	case __NR_fork:
123		name = "fork()";
124		break;
125	case __NR_execve:
126		name = "execve()";
127		break;
128	default:
129		break;
130	}
131
132	switch (bench_format) {
133	case BENCH_FORMAT_DEFAULT:
134		printf("# Executed %'d %s calls\n", loops, name);
135
136		result_usec = diff.tv_sec * 1000000;
137		result_usec += diff.tv_usec;
138
139		printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
140		       (unsigned long) diff.tv_sec,
141		       (unsigned long) (diff.tv_usec/1000));
142
143		printf(" %14lf usecs/op\n",
144		       (double)result_usec / (double)loops);
145		printf(" %'14d ops/sec\n",
146		       (int)((double)loops /
147			     ((double)result_usec / (double)1000000)));
148		break;
149
150	case BENCH_FORMAT_SIMPLE:
151		printf("%lu.%03lu\n",
152		       (unsigned long) diff.tv_sec,
153		       (unsigned long) (diff.tv_usec / 1000));
154		break;
155
156	default:
157		/* reaching here is something disaster */
158		fprintf(stderr, "Unknown format:%d\n", bench_format);
159		exit(1);
160		break;
161	}
162
163	return 0;
164}
165
166int bench_syscall_basic(int argc, const char **argv)
167{
168	return bench_syscall_common(argc, argv, __NR_getppid);
169}
170
171int bench_syscall_getpgid(int argc, const char **argv)
172{
173	return bench_syscall_common(argc, argv, __NR_getpgid);
174}
175
176int bench_syscall_fork(int argc, const char **argv)
177{
178	return bench_syscall_common(argc, argv, __NR_fork);
179}
180
181int bench_syscall_execve(int argc, const char **argv)
182{
183	return bench_syscall_common(argc, argv, __NR_execve);
184}