Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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#define LOOPS_DEFAULT 10000000
22static int loops = LOOPS_DEFAULT;
23
24static const struct option options[] = {
25 OPT_INTEGER('l', "loop", &loops, "Specify number of loops"),
26 OPT_END()
27};
28
29static const char * const bench_syscall_usage[] = {
30 "perf bench syscall <options>",
31 NULL
32};
33
34static void test_execve(void)
35{
36 const char *pathname = "/bin/true";
37 char *const argv[] = { (char *)pathname, NULL };
38 pid_t pid = fork();
39
40 if (pid < 0) {
41 fprintf(stderr, "fork failed\n");
42 exit(1);
43 } else if (pid == 0) {
44 execve(pathname, argv, NULL);
45 fprintf(stderr, "execve /bin/true failed\n");
46 exit(1);
47 } else {
48 if (waitpid(pid, NULL, 0) < 0) {
49 fprintf(stderr, "waitpid failed\n");
50 exit(1);
51 }
52 }
53}
54
55static int bench_syscall_common(int argc, const char **argv, int syscall)
56{
57 struct timeval start, stop, diff;
58 unsigned long long result_usec = 0;
59 const char *name = NULL;
60 int i;
61
62 argc = parse_options(argc, argv, options, bench_syscall_usage, 0);
63
64 gettimeofday(&start, NULL);
65
66 for (i = 0; i < loops; i++) {
67 switch (syscall) {
68 case __NR_getppid:
69 getppid();
70 break;
71 case __NR_getpgid:
72 getpgid(0);
73 break;
74 case __NR_execve:
75 test_execve();
76 /* Only loop 10000 times to save time */
77 if (i == 10000)
78 loops = 10000;
79 break;
80 default:
81 break;
82 }
83 }
84
85 gettimeofday(&stop, NULL);
86 timersub(&stop, &start, &diff);
87
88 switch (syscall) {
89 case __NR_getppid:
90 name = "getppid()";
91 break;
92 case __NR_getpgid:
93 name = "getpgid()";
94 break;
95 case __NR_execve:
96 name = "execve()";
97 break;
98 default:
99 break;
100 }
101
102 switch (bench_format) {
103 case BENCH_FORMAT_DEFAULT:
104 printf("# Executed %'d %s calls\n", loops, name);
105
106 result_usec = diff.tv_sec * 1000000;
107 result_usec += diff.tv_usec;
108
109 printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
110 (unsigned long) diff.tv_sec,
111 (unsigned long) (diff.tv_usec/1000));
112
113 printf(" %14lf usecs/op\n",
114 (double)result_usec / (double)loops);
115 printf(" %'14d ops/sec\n",
116 (int)((double)loops /
117 ((double)result_usec / (double)1000000)));
118 break;
119
120 case BENCH_FORMAT_SIMPLE:
121 printf("%lu.%03lu\n",
122 (unsigned long) diff.tv_sec,
123 (unsigned long) (diff.tv_usec / 1000));
124 break;
125
126 default:
127 /* reaching here is something disaster */
128 fprintf(stderr, "Unknown format:%d\n", bench_format);
129 exit(1);
130 break;
131 }
132
133 return 0;
134}
135
136int bench_syscall_basic(int argc, const char **argv)
137{
138 return bench_syscall_common(argc, argv, __NR_getppid);
139}
140
141int bench_syscall_getpgid(int argc, const char **argv)
142{
143 return bench_syscall_common(argc, argv, __NR_getpgid);
144}
145
146int bench_syscall_execve(int argc, const char **argv)
147{
148 return bench_syscall_common(argc, argv, __NR_execve);
149}