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