1
2#define _GNU_SOURCE
3
4#include <assert.h>
5#include <fcntl.h>
6#include <linux/perf_event.h>
7#include <sched.h>
8#include <stdio.h>
9#include <stdlib.h>
10#include <sys/ioctl.h>
11#include <sys/resource.h>
12#include <sys/time.h>
13#include <sys/types.h>
14#include <sys/wait.h>
15#include <unistd.h>
16
17#include <bpf/bpf.h>
18#include <bpf/libbpf.h>
19#include "perf-sys.h"
20
21#define SAMPLE_PERIOD 0x7fffffffffffffffULL
22
23
24static int map_fd[3];
25
26static void check_on_cpu(int cpu, struct perf_event_attr *attr)
27{
28 struct bpf_perf_event_value value2;
29 int pmu_fd, error = 0;
30 cpu_set_t set;
31 __u64 value;
32
33
34 CPU_ZERO(&set);
35 CPU_SET(cpu, &set);
36 assert(sched_setaffinity(0, sizeof(set), &set) == 0);
37
38 pmu_fd = sys_perf_event_open(attr, -1, cpu, -1, 0);
39 if (pmu_fd < 0) {
40 fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
41 error = 1;
42 goto on_exit;
43 }
44 assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
45 assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
46
47 bpf_map_get_next_key(map_fd[1], &cpu, NULL);
48
49 if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
50 fprintf(stderr, "Value missing for CPU %d\n", cpu);
51 error = 1;
52 goto on_exit;
53 } else {
54 fprintf(stderr, "CPU %d: %llu\n", cpu, value);
55 }
56
57 if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) {
58 fprintf(stderr, "Value2 missing for CPU %d\n", cpu);
59 error = 1;
60 goto on_exit;
61 } else {
62 fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu,
63 value2.counter, value2.enabled, value2.running);
64 }
65
66on_exit:
67 assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
68 assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
69 assert(close(pmu_fd) == 0 || error);
70 assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
71 exit(error);
72}
73
74static void test_perf_event_array(struct perf_event_attr *attr,
75 const char *name)
76{
77 int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
78 pid_t pid[nr_cpus];
79 int err = 0;
80
81 printf("Test reading %s counters\n", name);
82
83 for (i = 0; i < nr_cpus; i++) {
84 pid[i] = fork();
85 assert(pid[i] >= 0);
86 if (pid[i] == 0) {
87 check_on_cpu(i, attr);
88 exit(1);
89 }
90 }
91
92 for (i = 0; i < nr_cpus; i++) {
93 assert(waitpid(pid[i], &status, 0) == pid[i]);
94 err |= status;
95 }
96
97 if (err)
98 printf("Test: %s FAILED\n", name);
99}
100
101static void test_bpf_perf_event(void)
102{
103 struct perf_event_attr attr_cycles = {
104 .freq = 0,
105 .sample_period = SAMPLE_PERIOD,
106 .inherit = 0,
107 .type = PERF_TYPE_HARDWARE,
108 .read_format = 0,
109 .sample_type = 0,
110 .config = PERF_COUNT_HW_CPU_CYCLES,
111 };
112 struct perf_event_attr attr_clock = {
113 .freq = 0,
114 .sample_period = SAMPLE_PERIOD,
115 .inherit = 0,
116 .type = PERF_TYPE_SOFTWARE,
117 .read_format = 0,
118 .sample_type = 0,
119 .config = PERF_COUNT_SW_CPU_CLOCK,
120 };
121 struct perf_event_attr attr_raw = {
122 .freq = 0,
123 .sample_period = SAMPLE_PERIOD,
124 .inherit = 0,
125 .type = PERF_TYPE_RAW,
126 .read_format = 0,
127 .sample_type = 0,
128
129 .config = 0xc0,
130 };
131 struct perf_event_attr attr_l1d_load = {
132 .freq = 0,
133 .sample_period = SAMPLE_PERIOD,
134 .inherit = 0,
135 .type = PERF_TYPE_HW_CACHE,
136 .read_format = 0,
137 .sample_type = 0,
138 .config =
139 PERF_COUNT_HW_CACHE_L1D |
140 (PERF_COUNT_HW_CACHE_OP_READ << 8) |
141 (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
142 };
143 struct perf_event_attr attr_llc_miss = {
144 .freq = 0,
145 .sample_period = SAMPLE_PERIOD,
146 .inherit = 0,
147 .type = PERF_TYPE_HW_CACHE,
148 .read_format = 0,
149 .sample_type = 0,
150 .config =
151 PERF_COUNT_HW_CACHE_LL |
152 (PERF_COUNT_HW_CACHE_OP_READ << 8) |
153 (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
154 };
155 struct perf_event_attr attr_msr_tsc = {
156 .freq = 0,
157 .sample_period = 0,
158 .inherit = 0,
159
160 .type = 7,
161 .read_format = 0,
162 .sample_type = 0,
163 .config = 0,
164 };
165
166 test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
167 test_perf_event_array(&attr_clock, "SOFTWARE-clock");
168 test_perf_event_array(&attr_raw, "RAW-instruction-retired");
169 test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
170
171
172 test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
173 test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
174}
175
176int main(int argc, char **argv)
177{
178 struct bpf_link *links[2];
179 struct bpf_program *prog;
180 struct bpf_object *obj;
181 char filename[256];
182 int i = 0;
183
184 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
185 obj = bpf_object__open_file(filename, NULL);
186 if (libbpf_get_error(obj)) {
187 fprintf(stderr, "ERROR: opening BPF object file failed\n");
188 return 0;
189 }
190
191
192 if (bpf_object__load(obj)) {
193 fprintf(stderr, "ERROR: loading BPF object file failed\n");
194 goto cleanup;
195 }
196
197 map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counters");
198 map_fd[1] = bpf_object__find_map_fd_by_name(obj, "values");
199 map_fd[2] = bpf_object__find_map_fd_by_name(obj, "values2");
200 if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) {
201 fprintf(stderr, "ERROR: finding a map in obj file failed\n");
202 goto cleanup;
203 }
204
205 bpf_object__for_each_program(prog, obj) {
206 links[i] = bpf_program__attach(prog);
207 if (libbpf_get_error(links[i])) {
208 fprintf(stderr, "ERROR: bpf_program__attach failed\n");
209 links[i] = NULL;
210 goto cleanup;
211 }
212 i++;
213 }
214
215 test_bpf_perf_event();
216
217cleanup:
218 for (i--; i >= 0; i--)
219 bpf_link__destroy(links[i]);
220
221 bpf_object__close(obj);
222 return 0;
223}
224
