1 /* Copyright (c) 2016 Facebook
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
14 #include <sys/ioctl.h>
15 #include <linux/perf_event.h>
16 #include <linux/bpf.h>
20 #include <sys/resource.h>
24 #define SAMPLE_FREQ 50
26 static bool sys_read_seen, sys_write_seen;
28 static void print_ksym(__u64 addr)
34 sym = ksym_search(addr);
35 printf("%s;", sym->name);
36 if (!strstr(sym->name, "sys_read"))
38 else if (!strstr(sym->name, "sys_write"))
39 sys_write_seen = true;
42 static void print_addr(__u64 addr)
46 printf("%llx;", addr);
49 #define TASK_COMM_LEN 16
52 char comm[TASK_COMM_LEN];
57 static void print_stack(struct key_t *key, __u64 count)
59 __u64 ip[PERF_MAX_STACK_DEPTH] = {};
63 printf("%3lld %s;", count, key->comm);
64 if (bpf_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
67 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
71 if (bpf_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
74 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
79 if (key->kernstack == -EEXIST && !warned) {
80 printf("stackmap collisions seen. Consider increasing size\n");
82 } else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
83 printf("err stackid %d %d\n", key->kernstack, key->userstack);
87 static void int_exit(int sig)
93 static void print_stacks(void)
95 struct key_t key = {}, next_key;
97 __u32 stackid = 0, next_id;
98 int fd = map_fd[0], stack_map = map_fd[1];
100 sys_read_seen = sys_write_seen = false;
101 while (bpf_get_next_key(fd, &key, &next_key) == 0) {
102 bpf_lookup_elem(fd, &next_key, &value);
103 print_stack(&next_key, value);
104 bpf_delete_elem(fd, &next_key);
108 if (!sys_read_seen || !sys_write_seen) {
109 printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
113 /* clear stack map */
114 while (bpf_get_next_key(stack_map, &stackid, &next_id) == 0) {
115 bpf_delete_elem(stack_map, &next_id);
120 static void test_perf_event_all_cpu(struct perf_event_attr *attr)
122 int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
123 int *pmu_fd = malloc(nr_cpus * sizeof(int));
126 /* open perf_event on all cpus */
127 for (i = 0; i < nr_cpus; i++) {
128 pmu_fd[i] = perf_event_open(attr, -1, i, -1, 0);
130 printf("perf_event_open failed\n");
133 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
134 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0) == 0);
136 system("dd if=/dev/zero of=/dev/null count=5000k");
139 for (i--; i >= 0; i--)
144 static void test_perf_event_task(struct perf_event_attr *attr)
148 /* open task bound event */
149 pmu_fd = perf_event_open(attr, 0, -1, -1, 0);
151 printf("perf_event_open failed\n");
154 assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
155 assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
156 system("dd if=/dev/zero of=/dev/null count=5000k");
161 static void test_bpf_perf_event(void)
163 struct perf_event_attr attr_type_hw = {
164 .sample_freq = SAMPLE_FREQ,
166 .type = PERF_TYPE_HARDWARE,
167 .config = PERF_COUNT_HW_CPU_CYCLES,
170 struct perf_event_attr attr_type_sw = {
171 .sample_freq = SAMPLE_FREQ,
173 .type = PERF_TYPE_SOFTWARE,
174 .config = PERF_COUNT_SW_CPU_CLOCK,
178 test_perf_event_all_cpu(&attr_type_hw);
179 test_perf_event_task(&attr_type_hw);
180 test_perf_event_all_cpu(&attr_type_sw);
181 test_perf_event_task(&attr_type_sw);
185 int main(int argc, char **argv)
187 struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
190 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
191 setrlimit(RLIMIT_MEMLOCK, &r);
193 signal(SIGINT, int_exit);
195 if (load_kallsyms()) {
196 printf("failed to process /proc/kallsyms\n");
200 if (load_bpf_file(filename)) {
201 printf("%s", bpf_log_buf);
209 test_bpf_perf_event();