1 /* This program is free software; you can redistribute it and/or
2  * modify it under the terms of version 2 of the GNU General Public
3  * License as published by the Free Software Foundation.
4  */
5 #include <stdio.h>
6 #include <unistd.h>
7 #include <stdlib.h>
8 #include <stdbool.h>
9 #include <string.h>
10 #include <fcntl.h>
11 #include <poll.h>
12 #include <linux/perf_event.h>
13 #include <linux/bpf.h>
14 #include <errno.h>
15 #include <assert.h>
16 #include <sys/syscall.h>
17 #include <sys/ioctl.h>
18 #include <sys/mman.h>
19 #include <time.h>
20 #include <signal.h>
21 #include <libbpf.h>
22 #include "bpf_load.h"
23 #include "perf-sys.h"
24 #include "trace_helpers.h"
25 
26 static int pmu_fd;
27 
28 static __u64 time_get_ns(void)
29 {
30 	struct timespec ts;
31 
32 	clock_gettime(CLOCK_MONOTONIC, &ts);
33 	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
34 }
35 
36 static __u64 start_time;
37 
38 #define MAX_CNT 100000ll
39 
40 static int print_bpf_output(void *data, int size)
41 {
42 	static __u64 cnt;
43 	struct {
44 		__u64 pid;
45 		__u64 cookie;
46 	} *e = data;
47 
48 	if (e->cookie != 0x12345678) {
49 		printf("BUG pid %llx cookie %llx sized %d\n",
50 		       e->pid, e->cookie, size);
51 		return LIBBPF_PERF_EVENT_ERROR;
52 	}
53 
54 	cnt++;
55 
56 	if (cnt == MAX_CNT) {
57 		printf("recv %lld events per sec\n",
58 		       MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
59 		return LIBBPF_PERF_EVENT_DONE;
60 	}
61 
62 	return LIBBPF_PERF_EVENT_CONT;
63 }
64 
65 static void test_bpf_perf_event(void)
66 {
67 	struct perf_event_attr attr = {
68 		.sample_type = PERF_SAMPLE_RAW,
69 		.type = PERF_TYPE_SOFTWARE,
70 		.config = PERF_COUNT_SW_BPF_OUTPUT,
71 	};
72 	int key = 0;
73 
74 	pmu_fd = sys_perf_event_open(&attr, -1/*pid*/, 0/*cpu*/, -1/*group_fd*/, 0);
75 
76 	assert(pmu_fd >= 0);
77 	assert(bpf_map_update_elem(map_fd[0], &key, &pmu_fd, BPF_ANY) == 0);
78 	ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
79 }
80 
81 int main(int argc, char **argv)
82 {
83 	char filename[256];
84 	FILE *f;
85 	int ret;
86 
87 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
88 
89 	if (load_bpf_file(filename)) {
90 		printf("%s", bpf_log_buf);
91 		return 1;
92 	}
93 
94 	test_bpf_perf_event();
95 
96 	if (perf_event_mmap(pmu_fd) < 0)
97 		return 1;
98 
99 	f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
100 	(void) f;
101 
102 	start_time = time_get_ns();
103 	ret = perf_event_poller(pmu_fd, print_bpf_output);
104 	kill(0, SIGINT);
105 	return ret;
106 }
107