1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
#define _GNU_SOURCE
#include <assert.h>
#include <fcntl.h>
#include <linux/perf_event.h>
#include <linux/bpf.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "bpf_load.h"
#include "libbpf.h"
#include "perf-sys.h"
#define SAMPLE_PERIOD 0x7fffffffffffffffULL
static void check_on_cpu(int cpu, struct perf_event_attr *attr)
{
int pmu_fd, error = 0;
cpu_set_t set;
__u64 value;
/* Move to target CPU */
CPU_ZERO(&set);
CPU_SET(cpu, &set);
assert(sched_setaffinity(0, sizeof(set), &set) == 0);
/* Open perf event and attach to the perf_event_array */
pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0);
if (pmu_fd < 0) {
fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
error = 1;
goto on_exit;
}
assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
/* Trigger the kprobe */
bpf_map_get_next_key(map_fd[1], &cpu, NULL);
/* Check the value */
if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
fprintf(stderr, "Value missing for CPU %d\n", cpu);
error = 1;
goto on_exit;
}
fprintf(stderr, "CPU %d: %llu\n", cpu, value);
on_exit:
assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
assert(close(pmu_fd) == 0 || error);
assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
exit(error);
}
static void test_perf_event_array(struct perf_event_attr *attr,
const char *name)
{
int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
pid_t pid[nr_cpus];
int err = 0;
printf("Test reading %s counters\n", name);
for (i = 0; i < nr_cpus; i++) {
pid[i] = fork();
assert(pid[i] >= 0);
if (pid[i] == 0) {
check_on_cpu(i, attr);
exit(1);
}
}
for (i = 0; i < nr_cpus; i++) {
assert(waitpid(pid[i], &status, 0) == pid[i]);
err |= status;
}
if (err)
printf("Test: %s FAILED\n", name);
}
static void test_bpf_perf_event(void)
{
struct perf_event_attr attr_cycles = {
.freq = 0,
.sample_period = SAMPLE_PERIOD,
.inherit = 0,
.type = PERF_TYPE_HARDWARE,
.read_format = 0,
.sample_type = 0,
.config = PERF_COUNT_HW_CPU_CYCLES,
};
struct perf_event_attr attr_clock = {
.freq = 0,
.sample_period = SAMPLE_PERIOD,
.inherit = 0,
.type = PERF_TYPE_SOFTWARE,
.read_format = 0,
.sample_type = 0,
.config = PERF_COUNT_SW_CPU_CLOCK,
};
struct perf_event_attr attr_raw = {
.freq = 0,
.sample_period = SAMPLE_PERIOD,
.inherit = 0,
.type = PERF_TYPE_RAW,
.read_format = 0,
.sample_type = 0,
/* Intel Instruction Retired */
.config = 0xc0,
};
struct perf_event_attr attr_l1d_load = {
.freq = 0,
.sample_period = SAMPLE_PERIOD,
.inherit = 0,
.type = PERF_TYPE_HW_CACHE,
.read_format = 0,
.sample_type = 0,
.config =
PERF_COUNT_HW_CACHE_L1D |
(PERF_COUNT_HW_CACHE_OP_READ << 8) |
(PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
};
struct perf_event_attr attr_llc_miss = {
.freq = 0,
.sample_period = SAMPLE_PERIOD,
.inherit = 0,
.type = PERF_TYPE_HW_CACHE,
.read_format = 0,
.sample_type = 0,
.config =
PERF_COUNT_HW_CACHE_LL |
(PERF_COUNT_HW_CACHE_OP_READ << 8) |
(PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
};
struct perf_event_attr attr_msr_tsc = {
.freq = 0,
.sample_period = 0,
.inherit = 0,
/* From /sys/bus/event_source/devices/msr/ */
.type = 7,
.read_format = 0,
.sample_type = 0,
.config = 0,
};
test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
test_perf_event_array(&attr_clock, "SOFTWARE-clock");
test_perf_event_array(&attr_raw, "RAW-instruction-retired");
test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
/* below tests may fail in qemu */
test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
}
int main(int argc, char **argv)
{
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
char filename[256];
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
setrlimit(RLIMIT_MEMLOCK, &r);
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
}
test_bpf_perf_event();
return 0;
}
|
