1 #define _GNU_SOURCE 2 3 #include <assert.h> 4 #include <fcntl.h> 5 #include <linux/perf_event.h> 6 #include <linux/bpf.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_load.h" 18 #include "libbpf.h" 19 #include "perf-sys.h" 20 21 #define SAMPLE_PERIOD 0x7fffffffffffffffULL 22 23 static void check_on_cpu(int cpu, struct perf_event_attr *attr) 24 { 25 int pmu_fd, error = 0; 26 cpu_set_t set; 27 __u64 value; 28 29 /* Move to target CPU */ 30 CPU_ZERO(&set); 31 CPU_SET(cpu, &set); 32 assert(sched_setaffinity(0, sizeof(set), &set) == 0); 33 /* Open perf event and attach to the perf_event_array */ 34 pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0); 35 if (pmu_fd < 0) { 36 fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu); 37 error = 1; 38 goto on_exit; 39 } 40 assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0); 41 assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0); 42 /* Trigger the kprobe */ 43 bpf_map_get_next_key(map_fd[1], &cpu, NULL); 44 /* Check the value */ 45 if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) { 46 fprintf(stderr, "Value missing for CPU %d\n", cpu); 47 error = 1; 48 goto on_exit; 49 } 50 fprintf(stderr, "CPU %d: %llu\n", cpu, value); 51 52 on_exit: 53 assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error); 54 assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error); 55 assert(close(pmu_fd) == 0 || error); 56 assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error); 57 exit(error); 58 } 59 60 static void test_perf_event_array(struct perf_event_attr *attr, 61 const char *name) 62 { 63 int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF); 64 pid_t pid[nr_cpus]; 65 int err = 0; 66 67 printf("Test reading %s counters\n", name); 68 69 for (i = 0; i < nr_cpus; i++) { 70 pid[i] = fork(); 71 assert(pid[i] >= 0); 72 if (pid[i] == 0) { 73 check_on_cpu(i, attr); 74 exit(1); 75 } 76 } 77 78 for (i = 0; i < nr_cpus; i++) { 79 assert(waitpid(pid[i], &status, 0) == pid[i]); 80 err |= status; 81 } 82 83 if (err) 84 printf("Test: %s FAILED\n", name); 85 } 86 87 static void test_bpf_perf_event(void) 88 { 89 struct perf_event_attr attr_cycles = { 90 .freq = 0, 91 .sample_period = SAMPLE_PERIOD, 92 .inherit = 0, 93 .type = PERF_TYPE_HARDWARE, 94 .read_format = 0, 95 .sample_type = 0, 96 .config = PERF_COUNT_HW_CPU_CYCLES, 97 }; 98 struct perf_event_attr attr_clock = { 99 .freq = 0, 100 .sample_period = SAMPLE_PERIOD, 101 .inherit = 0, 102 .type = PERF_TYPE_SOFTWARE, 103 .read_format = 0, 104 .sample_type = 0, 105 .config = PERF_COUNT_SW_CPU_CLOCK, 106 }; 107 struct perf_event_attr attr_raw = { 108 .freq = 0, 109 .sample_period = SAMPLE_PERIOD, 110 .inherit = 0, 111 .type = PERF_TYPE_RAW, 112 .read_format = 0, 113 .sample_type = 0, 114 /* Intel Instruction Retired */ 115 .config = 0xc0, 116 }; 117 struct perf_event_attr attr_l1d_load = { 118 .freq = 0, 119 .sample_period = SAMPLE_PERIOD, 120 .inherit = 0, 121 .type = PERF_TYPE_HW_CACHE, 122 .read_format = 0, 123 .sample_type = 0, 124 .config = 125 PERF_COUNT_HW_CACHE_L1D | 126 (PERF_COUNT_HW_CACHE_OP_READ << 8) | 127 (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16), 128 }; 129 struct perf_event_attr attr_llc_miss = { 130 .freq = 0, 131 .sample_period = SAMPLE_PERIOD, 132 .inherit = 0, 133 .type = PERF_TYPE_HW_CACHE, 134 .read_format = 0, 135 .sample_type = 0, 136 .config = 137 PERF_COUNT_HW_CACHE_LL | 138 (PERF_COUNT_HW_CACHE_OP_READ << 8) | 139 (PERF_COUNT_HW_CACHE_RESULT_MISS << 16), 140 }; 141 struct perf_event_attr attr_msr_tsc = { 142 .freq = 0, 143 .sample_period = 0, 144 .inherit = 0, 145 /* From /sys/bus/event_source/devices/msr/ */ 146 .type = 7, 147 .read_format = 0, 148 .sample_type = 0, 149 .config = 0, 150 }; 151 152 test_perf_event_array(&attr_cycles, "HARDWARE-cycles"); 153 test_perf_event_array(&attr_clock, "SOFTWARE-clock"); 154 test_perf_event_array(&attr_raw, "RAW-instruction-retired"); 155 test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load"); 156 157 /* below tests may fail in qemu */ 158 test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss"); 159 test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc"); 160 } 161 162 int main(int argc, char **argv) 163 { 164 struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; 165 char filename[256]; 166 167 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 168 169 setrlimit(RLIMIT_MEMLOCK, &r); 170 if (load_bpf_file(filename)) { 171 printf("%s", bpf_log_buf); 172 return 1; 173 } 174 175 test_bpf_perf_event(); 176 return 0; 177 } 178