1 // SPDX-License-Identifier: GPL-2.0 2 #define _GNU_SOURCE 3 4 #include <assert.h> 5 #include <fcntl.h> 6 #include <linux/perf_event.h> 7 #include <linux/bpf.h> 8 #include <sched.h> 9 #include <stdio.h> 10 #include <stdlib.h> 11 #include <sys/ioctl.h> 12 #include <sys/resource.h> 13 #include <sys/time.h> 14 #include <sys/types.h> 15 #include <sys/wait.h> 16 #include <unistd.h> 17 18 #include "bpf_load.h" 19 #include "libbpf.h" 20 #include "perf-sys.h" 21 22 #define SAMPLE_PERIOD 0x7fffffffffffffffULL 23 24 static void check_on_cpu(int cpu, struct perf_event_attr *attr) 25 { 26 int pmu_fd, error = 0; 27 cpu_set_t set; 28 __u64 value; 29 30 /* Move to target CPU */ 31 CPU_ZERO(&set); 32 CPU_SET(cpu, &set); 33 assert(sched_setaffinity(0, sizeof(set), &set) == 0); 34 /* Open perf event and attach to the perf_event_array */ 35 pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0); 36 if (pmu_fd < 0) { 37 fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu); 38 error = 1; 39 goto on_exit; 40 } 41 assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0); 42 assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0); 43 /* Trigger the kprobe */ 44 bpf_map_get_next_key(map_fd[1], &cpu, NULL); 45 /* Check the value */ 46 if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) { 47 fprintf(stderr, "Value missing for CPU %d\n", cpu); 48 error = 1; 49 goto on_exit; 50 } 51 fprintf(stderr, "CPU %d: %llu\n", cpu, value); 52 53 on_exit: 54 assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error); 55 assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error); 56 assert(close(pmu_fd) == 0 || error); 57 assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error); 58 exit(error); 59 } 60 61 static void test_perf_event_array(struct perf_event_attr *attr, 62 const char *name) 63 { 64 int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF); 65 pid_t pid[nr_cpus]; 66 int err = 0; 67 68 printf("Test reading %s counters\n", name); 69 70 for (i = 0; i < nr_cpus; i++) { 71 pid[i] = fork(); 72 assert(pid[i] >= 0); 73 if (pid[i] == 0) { 74 check_on_cpu(i, attr); 75 exit(1); 76 } 77 } 78 79 for (i = 0; i < nr_cpus; i++) { 80 assert(waitpid(pid[i], &status, 0) == pid[i]); 81 err |= status; 82 } 83 84 if (err) 85 printf("Test: %s FAILED\n", name); 86 } 87 88 static void test_bpf_perf_event(void) 89 { 90 struct perf_event_attr attr_cycles = { 91 .freq = 0, 92 .sample_period = SAMPLE_PERIOD, 93 .inherit = 0, 94 .type = PERF_TYPE_HARDWARE, 95 .read_format = 0, 96 .sample_type = 0, 97 .config = PERF_COUNT_HW_CPU_CYCLES, 98 }; 99 struct perf_event_attr attr_clock = { 100 .freq = 0, 101 .sample_period = SAMPLE_PERIOD, 102 .inherit = 0, 103 .type = PERF_TYPE_SOFTWARE, 104 .read_format = 0, 105 .sample_type = 0, 106 .config = PERF_COUNT_SW_CPU_CLOCK, 107 }; 108 struct perf_event_attr attr_raw = { 109 .freq = 0, 110 .sample_period = SAMPLE_PERIOD, 111 .inherit = 0, 112 .type = PERF_TYPE_RAW, 113 .read_format = 0, 114 .sample_type = 0, 115 /* Intel Instruction Retired */ 116 .config = 0xc0, 117 }; 118 struct perf_event_attr attr_l1d_load = { 119 .freq = 0, 120 .sample_period = SAMPLE_PERIOD, 121 .inherit = 0, 122 .type = PERF_TYPE_HW_CACHE, 123 .read_format = 0, 124 .sample_type = 0, 125 .config = 126 PERF_COUNT_HW_CACHE_L1D | 127 (PERF_COUNT_HW_CACHE_OP_READ << 8) | 128 (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16), 129 }; 130 struct perf_event_attr attr_llc_miss = { 131 .freq = 0, 132 .sample_period = SAMPLE_PERIOD, 133 .inherit = 0, 134 .type = PERF_TYPE_HW_CACHE, 135 .read_format = 0, 136 .sample_type = 0, 137 .config = 138 PERF_COUNT_HW_CACHE_LL | 139 (PERF_COUNT_HW_CACHE_OP_READ << 8) | 140 (PERF_COUNT_HW_CACHE_RESULT_MISS << 16), 141 }; 142 struct perf_event_attr attr_msr_tsc = { 143 .freq = 0, 144 .sample_period = 0, 145 .inherit = 0, 146 /* From /sys/bus/event_source/devices/msr/ */ 147 .type = 7, 148 .read_format = 0, 149 .sample_type = 0, 150 .config = 0, 151 }; 152 153 test_perf_event_array(&attr_cycles, "HARDWARE-cycles"); 154 test_perf_event_array(&attr_clock, "SOFTWARE-clock"); 155 test_perf_event_array(&attr_raw, "RAW-instruction-retired"); 156 test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load"); 157 158 /* below tests may fail in qemu */ 159 test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss"); 160 test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc"); 161 } 162 163 int main(int argc, char **argv) 164 { 165 struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; 166 char filename[256]; 167 168 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 169 170 setrlimit(RLIMIT_MEMLOCK, &r); 171 if (load_bpf_file(filename)) { 172 printf("%s", bpf_log_buf); 173 return 1; 174 } 175 176 test_bpf_perf_event(); 177 return 0; 178 } 179