1
2
3
4#define _GNU_SOURCE
5#include <sched.h>
6#include <errno.h>
7#include <stdio.h>
8#include <sys/types.h>
9#include <asm/unistd.h>
10#include <fcntl.h>
11#include <unistd.h>
12#include <assert.h>
13#include <sys/wait.h>
14#include <stdlib.h>
15#include <signal.h>
16#include <linux/bpf.h>
17#include <string.h>
18#include <time.h>
19#include <sys/resource.h>
20#include <bpf/bpf.h>
21#include <bpf/libbpf.h>
22
23#define MAX_CNT 1000000
24
25static struct bpf_link *links[2];
26static struct bpf_object *obj;
27static int cnt;
28
29static __u64 time_get_ns(void)
30{
31 struct timespec ts;
32
33 clock_gettime(CLOCK_MONOTONIC, &ts);
34 return ts.tv_sec * 1000000000ull + ts.tv_nsec;
35}
36
37static void test_task_rename(int cpu)
38{
39 __u64 start_time;
40 char buf[] = "test\n";
41 int i, fd;
42
43 fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
44 if (fd < 0) {
45 printf("couldn't open /proc\n");
46 exit(1);
47 }
48 start_time = time_get_ns();
49 for (i = 0; i < MAX_CNT; i++) {
50 if (write(fd, buf, sizeof(buf)) < 0) {
51 printf("task rename failed: %s\n", strerror(errno));
52 close(fd);
53 return;
54 }
55 }
56 printf("task_rename:%d: %lld events per sec\n",
57 cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
58 close(fd);
59}
60
61static void test_urandom_read(int cpu)
62{
63 __u64 start_time;
64 char buf[4];
65 int i, fd;
66
67 fd = open("/dev/urandom", O_RDONLY);
68 if (fd < 0) {
69 printf("couldn't open /dev/urandom\n");
70 exit(1);
71 }
72 start_time = time_get_ns();
73 for (i = 0; i < MAX_CNT; i++) {
74 if (read(fd, buf, sizeof(buf)) < 0) {
75 printf("failed to read from /dev/urandom: %s\n", strerror(errno));
76 close(fd);
77 return;
78 }
79 }
80 printf("urandom_read:%d: %lld events per sec\n",
81 cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
82 close(fd);
83}
84
85static void loop(int cpu, int flags)
86{
87 cpu_set_t cpuset;
88
89 CPU_ZERO(&cpuset);
90 CPU_SET(cpu, &cpuset);
91 sched_setaffinity(0, sizeof(cpuset), &cpuset);
92
93 if (flags & 1)
94 test_task_rename(cpu);
95 if (flags & 2)
96 test_urandom_read(cpu);
97}
98
99static void run_perf_test(int tasks, int flags)
100{
101 pid_t pid[tasks];
102 int i;
103
104 for (i = 0; i < tasks; i++) {
105 pid[i] = fork();
106 if (pid[i] == 0) {
107 loop(i, flags);
108 exit(0);
109 } else if (pid[i] == -1) {
110 printf("couldn't spawn #%d process\n", i);
111 exit(1);
112 }
113 }
114 for (i = 0; i < tasks; i++) {
115 int status;
116
117 assert(waitpid(pid[i], &status, 0) == pid[i]);
118 assert(status == 0);
119 }
120}
121
122static int load_progs(char *filename)
123{
124 struct bpf_program *prog;
125 int err = 0;
126
127 obj = bpf_object__open_file(filename, NULL);
128 err = libbpf_get_error(obj);
129 if (err < 0) {
130 fprintf(stderr, "ERROR: opening BPF object file failed\n");
131 return err;
132 }
133
134
135 err = bpf_object__load(obj);
136 if (err < 0) {
137 fprintf(stderr, "ERROR: loading BPF object file failed\n");
138 return err;
139 }
140
141 bpf_object__for_each_program(prog, obj) {
142 links[cnt] = bpf_program__attach(prog);
143 err = libbpf_get_error(links[cnt]);
144 if (err < 0) {
145 fprintf(stderr, "ERROR: bpf_program__attach failed\n");
146 links[cnt] = NULL;
147 return err;
148 }
149 cnt++;
150 }
151
152 return err;
153}
154
155static void unload_progs(void)
156{
157 while (cnt)
158 bpf_link__destroy(links[--cnt]);
159
160 bpf_object__close(obj);
161}
162
163int main(int argc, char **argv)
164{
165 int num_cpu = sysconf(_SC_NPROCESSORS_ONLN);
166 int test_flags = ~0;
167 char filename[256];
168 int err = 0;
169
170
171 if (argc > 1)
172 test_flags = atoi(argv[1]) ? : test_flags;
173 if (argc > 2)
174 num_cpu = atoi(argv[2]) ? : num_cpu;
175
176 if (test_flags & 0x3) {
177 printf("BASE\n");
178 run_perf_test(num_cpu, test_flags);
179 }
180
181 if (test_flags & 0xC) {
182 snprintf(filename, sizeof(filename),
183 "%s_kprobe_kern.o", argv[0]);
184
185 printf("w/KPROBE\n");
186 err = load_progs(filename);
187 if (!err)
188 run_perf_test(num_cpu, test_flags >> 2);
189
190 unload_progs();
191 }
192
193 if (test_flags & 0x30) {
194 snprintf(filename, sizeof(filename),
195 "%s_tp_kern.o", argv[0]);
196 printf("w/TRACEPOINT\n");
197 err = load_progs(filename);
198 if (!err)
199 run_perf_test(num_cpu, test_flags >> 4);
200
201 unload_progs();
202 }
203
204 if (test_flags & 0xC0) {
205 snprintf(filename, sizeof(filename),
206 "%s_raw_tp_kern.o", argv[0]);
207 printf("w/RAW_TRACEPOINT\n");
208 err = load_progs(filename);
209 if (!err)
210 run_perf_test(num_cpu, test_flags >> 6);
211
212 unload_progs();
213 }
214
215 return err;
216}
217
