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(unsigned long *llc_perf_miss) 87 { 88 __u64 total_misses; 89 int ret; 90 91 /* Stop counters after one span to get miss rate */ 92 93 ioctl(fd_lm, PERF_EVENT_IOC_DISABLE, 0); 94 95 ret = read(fd_lm, &rf_cqm, sizeof(struct read_format)); 96 if (ret == -1) { 97 ksft_perror("Could not get llc misses through perf"); 98 return -1; 99 } 100 101 total_misses = rf_cqm.values[0].value; 102 *llc_perf_miss = total_misses; 103 104 return 0; 105 } 106 107 /* 108 * Get LLC Occupancy as reported by RESCTRL FS 109 * For CMT, 110 * 1. If con_mon grp and mon grp given, then read from mon grp in 111 * con_mon grp 112 * 2. If only con_mon grp given, then read from con_mon grp 113 * 3. If both not given, then read from root con_mon grp 114 * For CAT, 115 * 1. If con_mon grp given, then read from it 116 * 2. If con_mon grp not given, then read from root con_mon grp 117 * 118 * Return: =0 on success. <0 on failure. 119 */ 120 static int get_llc_occu_resctrl(unsigned long *llc_occupancy) 121 { 122 FILE *fp; 123 124 fp = fopen(llc_occup_path, "r"); 125 if (!fp) { 126 ksft_perror("Failed to open results file"); 127 128 return -1; 129 } 130 if (fscanf(fp, "%lu", llc_occupancy) <= 0) { 131 ksft_perror("Could not get llc occupancy"); 132 fclose(fp); 133 134 return -1; 135 } 136 fclose(fp); 137 138 return 0; 139 } 140 141 /* 142 * print_results_cache: the cache results are stored in a file 143 * @filename: file that stores the results 144 * @bm_pid: child pid that runs benchmark 145 * @llc_value: perf miss value / 146 * llc occupancy value reported by resctrl FS 147 * 148 * Return: 0 on success, < 0 on error. 149 */ 150 static int print_results_cache(const char *filename, int bm_pid, 151 unsigned long llc_value) 152 { 153 FILE *fp; 154 155 if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) { 156 printf("Pid: %d \t LLC_value: %lu\n", bm_pid, 157 llc_value); 158 } else { 159 fp = fopen(filename, "a"); 160 if (!fp) { 161 ksft_perror("Cannot open results file"); 162 163 return -1; 164 } 165 fprintf(fp, "Pid: %d \t llc_value: %lu\n", bm_pid, llc_value); 166 fclose(fp); 167 } 168 169 return 0; 170 } 171 172 /* 173 * perf_event_measure - Measure perf events 174 * @filename: Filename for writing the results 175 * @bm_pid: PID that runs the benchmark 176 * 177 * Measures perf events (e.g., cache misses) and writes the results into 178 * @filename. @bm_pid is written to the results file along with the measured 179 * value. 180 * 181 * Return: =0 on success. <0 on failure. 182 */ 183 static int perf_event_measure(const char *filename, int bm_pid) 184 { 185 unsigned long llc_perf_miss = 0; 186 int ret; 187 188 ret = get_llc_perf(&llc_perf_miss); 189 if (ret < 0) 190 return ret; 191 192 return print_results_cache(filename, bm_pid, llc_perf_miss); 193 } 194 195 /* 196 * measure_llc_resctrl - Measure resctrl LLC value from resctrl 197 * @filename: Filename for writing the results 198 * @bm_pid: PID that runs the benchmark 199 * 200 * Measures LLC occupancy from resctrl and writes the results into @filename. 201 * @bm_pid is written to the results file along with the measured value. 202 * 203 * Return: =0 on success. <0 on failure. 204 */ 205 int measure_llc_resctrl(const char *filename, int bm_pid) 206 { 207 unsigned long llc_occu_resc = 0; 208 int ret; 209 210 ret = get_llc_occu_resctrl(&llc_occu_resc); 211 if (ret < 0) 212 return ret; 213 214 return print_results_cache(filename, bm_pid, llc_occu_resc); 215 } 216 217 /* 218 * cache_val: execute benchmark and measure LLC occupancy resctrl 219 * and perf cache miss for the benchmark 220 * @param: parameters passed to cache_val() 221 * @span: buffer size for the benchmark 222 * 223 * Return: 0 when the test was run, < 0 on error. 224 */ 225 int cat_val(struct resctrl_val_param *param, size_t span) 226 { 227 int memflush = 1, operation = 0, ret = 0; 228 char *resctrl_val = param->resctrl_val; 229 pid_t bm_pid; 230 231 if (strcmp(param->filename, "") == 0) 232 sprintf(param->filename, "stdio"); 233 234 bm_pid = getpid(); 235 236 /* Taskset benchmark to specified cpu */ 237 ret = taskset_benchmark(bm_pid, param->cpu_no); 238 if (ret) 239 return ret; 240 241 /* Write benchmark to specified con_mon grp, mon_grp in resctrl FS*/ 242 ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp, 243 resctrl_val); 244 if (ret) 245 return ret; 246 247 initialize_llc_perf(); 248 249 /* Test runs until the callback setup() tells the test to stop. */ 250 while (1) { 251 ret = param->setup(param); 252 if (ret == END_OF_TESTS) { 253 ret = 0; 254 break; 255 } 256 if (ret < 0) 257 break; 258 ret = reset_enable_llc_perf(bm_pid, param->cpu_no); 259 if (ret) 260 break; 261 262 if (run_fill_buf(span, memflush, operation, true)) { 263 fprintf(stderr, "Error-running fill buffer\n"); 264 ret = -1; 265 goto pe_close; 266 } 267 268 sleep(1); 269 ret = perf_event_measure(param->filename, bm_pid); 270 if (ret) 271 goto pe_close; 272 } 273 274 return ret; 275 276 pe_close: 277 close(fd_lm); 278 return ret; 279 } 280 281 /* 282 * show_cache_info: show cache test result information 283 * @sum_llc_val: sum of LLC cache result data 284 * @no_of_bits: number of bits 285 * @cache_span: cache span in bytes for CMT or in lines for CAT 286 * @max_diff: max difference 287 * @max_diff_percent: max difference percentage 288 * @num_of_runs: number of runs 289 * @platform: show test information on this platform 290 * @cmt: CMT test or CAT test 291 * 292 * Return: 0 on success. non-zero on failure. 293 */ 294 int show_cache_info(unsigned long sum_llc_val, int no_of_bits, 295 size_t cache_span, unsigned long max_diff, 296 unsigned long max_diff_percent, unsigned long num_of_runs, 297 bool platform, bool cmt) 298 { 299 unsigned long avg_llc_val = 0; 300 float diff_percent; 301 long avg_diff = 0; 302 int ret; 303 304 avg_llc_val = sum_llc_val / num_of_runs; 305 avg_diff = (long)abs(cache_span - avg_llc_val); 306 diff_percent = ((float)cache_span - avg_llc_val) / cache_span * 100; 307 308 ret = platform && abs((int)diff_percent) > max_diff_percent && 309 (cmt ? (abs(avg_diff) > max_diff) : true); 310 311 ksft_print_msg("%s Check cache miss rate within %lu%%\n", 312 ret ? "Fail:" : "Pass:", max_diff_percent); 313 314 ksft_print_msg("Percent diff=%d\n", abs((int)diff_percent)); 315 ksft_print_msg("Number of bits: %d\n", no_of_bits); 316 ksft_print_msg("Average LLC val: %lu\n", avg_llc_val); 317 ksft_print_msg("Cache span (%s): %zu\n", cmt ? "bytes" : "lines", 318 cache_span); 319 320 return ret; 321 } 322