1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <stdint.h> 4 #include "resctrl.h" 5 6 struct read_format { 7 __u64 nr; /* The number of events */ 8 struct { 9 __u64 value; /* The value of the event */ 10 } values[2]; 11 }; 12 13 static struct perf_event_attr pea_llc_miss; 14 static struct read_format rf_cqm; 15 static int fd_lm; 16 char llc_occup_path[1024]; 17 18 static void initialize_perf_event_attr(void) 19 { 20 pea_llc_miss.type = PERF_TYPE_HARDWARE; 21 pea_llc_miss.size = sizeof(struct perf_event_attr); 22 pea_llc_miss.read_format = PERF_FORMAT_GROUP; 23 pea_llc_miss.exclude_kernel = 1; 24 pea_llc_miss.exclude_hv = 1; 25 pea_llc_miss.exclude_idle = 1; 26 pea_llc_miss.exclude_callchain_kernel = 1; 27 pea_llc_miss.inherit = 1; 28 pea_llc_miss.exclude_guest = 1; 29 pea_llc_miss.disabled = 1; 30 } 31 32 static void ioctl_perf_event_ioc_reset_enable(void) 33 { 34 ioctl(fd_lm, PERF_EVENT_IOC_RESET, 0); 35 ioctl(fd_lm, PERF_EVENT_IOC_ENABLE, 0); 36 } 37 38 static int perf_event_open_llc_miss(pid_t pid, int cpu_no) 39 { 40 fd_lm = perf_event_open(&pea_llc_miss, pid, cpu_no, -1, 41 PERF_FLAG_FD_CLOEXEC); 42 if (fd_lm == -1) { 43 ksft_perror("Error opening leader"); 44 return -1; 45 } 46 47 return 0; 48 } 49 50 static void initialize_llc_perf(void) 51 { 52 memset(&pea_llc_miss, 0, sizeof(struct perf_event_attr)); 53 memset(&rf_cqm, 0, sizeof(struct read_format)); 54 55 /* Initialize perf_event_attr structures for HW_CACHE_MISSES */ 56 initialize_perf_event_attr(); 57 58 pea_llc_miss.config = PERF_COUNT_HW_CACHE_MISSES; 59 60 rf_cqm.nr = 1; 61 } 62 63 static int reset_enable_llc_perf(pid_t pid, int cpu_no) 64 { 65 int ret = 0; 66 67 ret = perf_event_open_llc_miss(pid, cpu_no); 68 if (ret < 0) 69 return ret; 70 71 /* Start counters to log values */ 72 ioctl_perf_event_ioc_reset_enable(); 73 74 return 0; 75 } 76 77 /* 78 * get_llc_perf: llc cache miss through perf events 79 * @llc_perf_miss: LLC miss counter that is filled on success 80 * 81 * Perf events like HW_CACHE_MISSES could be used to validate number of 82 * cache lines allocated. 83 * 84 * Return: =0 on success. <0 on failure. 85 */ 86 static int get_llc_perf(__u64 *llc_perf_miss) 87 { 88 int ret; 89 90 /* Stop counters after one span to get miss rate */ 91 92 ioctl(fd_lm, PERF_EVENT_IOC_DISABLE, 0); 93 94 ret = read(fd_lm, &rf_cqm, sizeof(struct read_format)); 95 if (ret == -1) { 96 ksft_perror("Could not get llc misses through perf"); 97 return -1; 98 } 99 100 *llc_perf_miss = rf_cqm.values[0].value; 101 102 return 0; 103 } 104 105 /* 106 * Get LLC Occupancy as reported by RESCTRL FS 107 * For CMT, 108 * 1. If con_mon grp and mon grp given, then read from mon grp in 109 * con_mon grp 110 * 2. If only con_mon grp given, then read from con_mon grp 111 * 3. If both not given, then read from root con_mon grp 112 * For CAT, 113 * 1. If con_mon grp given, then read from it 114 * 2. If con_mon grp not given, then read from root con_mon grp 115 * 116 * Return: =0 on success. <0 on failure. 117 */ 118 static int get_llc_occu_resctrl(unsigned long *llc_occupancy) 119 { 120 FILE *fp; 121 122 fp = fopen(llc_occup_path, "r"); 123 if (!fp) { 124 ksft_perror("Failed to open results file"); 125 126 return -1; 127 } 128 if (fscanf(fp, "%lu", llc_occupancy) <= 0) { 129 ksft_perror("Could not get llc occupancy"); 130 fclose(fp); 131 132 return -1; 133 } 134 fclose(fp); 135 136 return 0; 137 } 138 139 /* 140 * print_results_cache: the cache results are stored in a file 141 * @filename: file that stores the results 142 * @bm_pid: child pid that runs benchmark 143 * @llc_value: perf miss value / 144 * llc occupancy value reported by resctrl FS 145 * 146 * Return: 0 on success, < 0 on error. 147 */ 148 static int print_results_cache(const char *filename, int bm_pid, __u64 llc_value) 149 { 150 FILE *fp; 151 152 if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) { 153 printf("Pid: %d \t LLC_value: %llu\n", bm_pid, llc_value); 154 } else { 155 fp = fopen(filename, "a"); 156 if (!fp) { 157 ksft_perror("Cannot open results file"); 158 159 return -1; 160 } 161 fprintf(fp, "Pid: %d \t llc_value: %llu\n", bm_pid, llc_value); 162 fclose(fp); 163 } 164 165 return 0; 166 } 167 168 /* 169 * perf_event_measure - Measure perf events 170 * @filename: Filename for writing the results 171 * @bm_pid: PID that runs the benchmark 172 * 173 * Measures perf events (e.g., cache misses) and writes the results into 174 * @filename. @bm_pid is written to the results file along with the measured 175 * value. 176 * 177 * Return: =0 on success. <0 on failure. 178 */ 179 static int perf_event_measure(const char *filename, int bm_pid) 180 { 181 __u64 llc_perf_miss = 0; 182 int ret; 183 184 ret = get_llc_perf(&llc_perf_miss); 185 if (ret < 0) 186 return ret; 187 188 return print_results_cache(filename, bm_pid, llc_perf_miss); 189 } 190 191 /* 192 * measure_llc_resctrl - Measure resctrl LLC value from resctrl 193 * @filename: Filename for writing the results 194 * @bm_pid: PID that runs the benchmark 195 * 196 * Measures LLC occupancy from resctrl and writes the results into @filename. 197 * @bm_pid is written to the results file along with the measured value. 198 * 199 * Return: =0 on success. <0 on failure. 200 */ 201 int measure_llc_resctrl(const char *filename, int bm_pid) 202 { 203 unsigned long llc_occu_resc = 0; 204 int ret; 205 206 ret = get_llc_occu_resctrl(&llc_occu_resc); 207 if (ret < 0) 208 return ret; 209 210 return print_results_cache(filename, bm_pid, llc_occu_resc); 211 } 212 213 /* 214 * cache_val: execute benchmark and measure LLC occupancy resctrl 215 * and perf cache miss for the benchmark 216 * @param: parameters passed to cache_val() 217 * @span: buffer size for the benchmark 218 * 219 * Return: 0 when the test was run, < 0 on error. 220 */ 221 int cat_val(struct resctrl_val_param *param, size_t span) 222 { 223 int memflush = 1, operation = 0, ret = 0; 224 char *resctrl_val = param->resctrl_val; 225 pid_t bm_pid; 226 227 if (strcmp(param->filename, "") == 0) 228 sprintf(param->filename, "stdio"); 229 230 bm_pid = getpid(); 231 232 /* Taskset benchmark to specified cpu */ 233 ret = taskset_benchmark(bm_pid, param->cpu_no); 234 if (ret) 235 return ret; 236 237 /* Write benchmark to specified con_mon grp, mon_grp in resctrl FS*/ 238 ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp, 239 resctrl_val); 240 if (ret) 241 return ret; 242 243 initialize_llc_perf(); 244 245 /* Test runs until the callback setup() tells the test to stop. */ 246 while (1) { 247 ret = param->setup(param); 248 if (ret == END_OF_TESTS) { 249 ret = 0; 250 break; 251 } 252 if (ret < 0) 253 break; 254 ret = reset_enable_llc_perf(bm_pid, param->cpu_no); 255 if (ret) 256 break; 257 258 if (run_fill_buf(span, memflush, operation, true)) { 259 fprintf(stderr, "Error-running fill buffer\n"); 260 ret = -1; 261 goto pe_close; 262 } 263 264 sleep(1); 265 ret = perf_event_measure(param->filename, bm_pid); 266 if (ret) 267 goto pe_close; 268 } 269 270 return ret; 271 272 pe_close: 273 close(fd_lm); 274 return ret; 275 } 276 277 /* 278 * show_cache_info - Show generic cache test information 279 * @no_of_bits: Number of bits 280 * @avg_llc_val: Average of LLC cache result data 281 * @cache_span: Cache span 282 * @lines: @cache_span in lines or bytes 283 */ 284 void show_cache_info(int no_of_bits, __u64 avg_llc_val, size_t cache_span, bool lines) 285 { 286 ksft_print_msg("Number of bits: %d\n", no_of_bits); 287 ksft_print_msg("Average LLC val: %llu\n", avg_llc_val); 288 ksft_print_msg("Cache span (%s): %zu\n", lines ? "lines" : "bytes", 289 cache_span); 290 } 291