1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <stdio.h>
3 #include <fcntl.h>
4 #include <poll.h>
5 #include <time.h>
6 #include <signal.h>
7 #include <bpf/libbpf.h>
8
time_get_ns(void)9 static __u64 time_get_ns(void)
10 {
11 struct timespec ts;
12
13 clock_gettime(CLOCK_MONOTONIC, &ts);
14 return ts.tv_sec * 1000000000ull + ts.tv_nsec;
15 }
16
17 static __u64 start_time;
18 static __u64 cnt;
19
20 #define MAX_CNT 100000ll
21
print_bpf_output(void * ctx,int cpu,void * data,__u32 size)22 static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
23 {
24 struct {
25 __u64 pid;
26 __u64 cookie;
27 } *e = data;
28
29 if (e->cookie != 0x12345678) {
30 printf("BUG pid %llx cookie %llx sized %d\n",
31 e->pid, e->cookie, size);
32 return;
33 }
34
35 cnt++;
36
37 if (cnt == MAX_CNT) {
38 printf("recv %lld events per sec\n",
39 MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
40 return;
41 }
42 }
43
main(int argc,char ** argv)44 int main(int argc, char **argv)
45 {
46 struct perf_buffer_opts pb_opts = {};
47 struct bpf_link *link = NULL;
48 struct bpf_program *prog;
49 struct perf_buffer *pb;
50 struct bpf_object *obj;
51 int map_fd, ret = 0;
52 char filename[256];
53 FILE *f;
54
55 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
56 obj = bpf_object__open_file(filename, NULL);
57 if (libbpf_get_error(obj)) {
58 fprintf(stderr, "ERROR: opening BPF object file failed\n");
59 return 0;
60 }
61
62 /* load BPF program */
63 if (bpf_object__load(obj)) {
64 fprintf(stderr, "ERROR: loading BPF object file failed\n");
65 goto cleanup;
66 }
67
68 map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
69 if (map_fd < 0) {
70 fprintf(stderr, "ERROR: finding a map in obj file failed\n");
71 goto cleanup;
72 }
73
74 prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
75 if (libbpf_get_error(prog)) {
76 fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
77 goto cleanup;
78 }
79
80 link = bpf_program__attach(prog);
81 if (libbpf_get_error(link)) {
82 fprintf(stderr, "ERROR: bpf_program__attach failed\n");
83 link = NULL;
84 goto cleanup;
85 }
86
87 pb_opts.sample_cb = print_bpf_output;
88 pb = perf_buffer__new(map_fd, 8, &pb_opts);
89 ret = libbpf_get_error(pb);
90 if (ret) {
91 printf("failed to setup perf_buffer: %d\n", ret);
92 return 1;
93 }
94
95 f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
96 (void) f;
97
98 start_time = time_get_ns();
99 while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) {
100 }
101 kill(0, SIGINT);
102
103 cleanup:
104 bpf_link__destroy(link);
105 bpf_object__close(obj);
106 return ret;
107 }
108