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
26 static int loops = LOOPS_DEFAULT;
27
28 static const struct option options[] = {
29 OPT_INTEGER('l', "loop", &loops, "Specify number of loops"),
30 OPT_END()
31 };
32
33 static const char * const bench_syscall_usage[] = {
34 "perf bench syscall <options>",
35 NULL
36 };
37
test_fork(void)38 static 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
test_execve(void)55 static 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
bench_syscall_common(int argc,const char ** argv,int syscall)76 static 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
bench_syscall_basic(int argc,const char ** argv)166 int bench_syscall_basic(int argc, const char **argv)
167 {
168 return bench_syscall_common(argc, argv, __NR_getppid);
169 }
170
bench_syscall_getpgid(int argc,const char ** argv)171 int bench_syscall_getpgid(int argc, const char **argv)
172 {
173 return bench_syscall_common(argc, argv, __NR_getpgid);
174 }
175
bench_syscall_fork(int argc,const char ** argv)176 int bench_syscall_fork(int argc, const char **argv)
177 {
178 return bench_syscall_common(argc, argv, __NR_fork);
179 }
180
bench_syscall_execve(int argc,const char ** argv)181 int bench_syscall_execve(int argc, const char **argv)
182 {
183 return bench_syscall_common(argc, argv, __NR_execve);
184 }
185