1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Memory bandwidth monitoring and allocation library 4 * 5 * Copyright (C) 2018 Intel Corporation 6 * 7 * Authors: 8 * Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>, 9 * Fenghua Yu <fenghua.yu@intel.com> 10 */ 11 #include "resctrl.h" 12 13 #define UNCORE_IMC "uncore_imc" 14 #define READ_FILE_NAME "events/cas_count_read" 15 #define WRITE_FILE_NAME "events/cas_count_write" 16 #define DYN_PMU_PATH "/sys/bus/event_source/devices" 17 #define SCALE 0.00006103515625 18 #define MAX_IMCS 20 19 #define MAX_TOKENS 5 20 #define READ 0 21 #define WRITE 1 22 #define CON_MON_MBM_LOCAL_BYTES_PATH \ 23 "%s/%s/mon_groups/%s/mon_data/mon_L3_%02d/mbm_local_bytes" 24 25 #define CON_MBM_LOCAL_BYTES_PATH \ 26 "%s/%s/mon_data/mon_L3_%02d/mbm_local_bytes" 27 28 #define MON_MBM_LOCAL_BYTES_PATH \ 29 "%s/mon_groups/%s/mon_data/mon_L3_%02d/mbm_local_bytes" 30 31 #define MBM_LOCAL_BYTES_PATH \ 32 "%s/mon_data/mon_L3_%02d/mbm_local_bytes" 33 34 #define CON_MON_LCC_OCCUP_PATH \ 35 "%s/%s/mon_groups/%s/mon_data/mon_L3_%02d/llc_occupancy" 36 37 #define CON_LCC_OCCUP_PATH \ 38 "%s/%s/mon_data/mon_L3_%02d/llc_occupancy" 39 40 #define MON_LCC_OCCUP_PATH \ 41 "%s/mon_groups/%s/mon_data/mon_L3_%02d/llc_occupancy" 42 43 #define LCC_OCCUP_PATH \ 44 "%s/mon_data/mon_L3_%02d/llc_occupancy" 45 46 struct membw_read_format { 47 __u64 value; /* The value of the event */ 48 __u64 time_enabled; /* if PERF_FORMAT_TOTAL_TIME_ENABLED */ 49 __u64 time_running; /* if PERF_FORMAT_TOTAL_TIME_RUNNING */ 50 __u64 id; /* if PERF_FORMAT_ID */ 51 }; 52 53 struct imc_counter_config { 54 __u32 type; 55 __u64 event; 56 __u64 umask; 57 struct perf_event_attr pe; 58 struct membw_read_format return_value; 59 int fd; 60 }; 61 62 static char mbm_total_path[1024]; 63 static int imcs; 64 static struct imc_counter_config imc_counters_config[MAX_IMCS][2]; 65 static const struct resctrl_test *current_test; 66 67 void membw_initialize_perf_event_attr(int i, int j) 68 { 69 memset(&imc_counters_config[i][j].pe, 0, 70 sizeof(struct perf_event_attr)); 71 imc_counters_config[i][j].pe.type = imc_counters_config[i][j].type; 72 imc_counters_config[i][j].pe.size = sizeof(struct perf_event_attr); 73 imc_counters_config[i][j].pe.disabled = 1; 74 imc_counters_config[i][j].pe.inherit = 1; 75 imc_counters_config[i][j].pe.exclude_guest = 0; 76 imc_counters_config[i][j].pe.config = 77 imc_counters_config[i][j].umask << 8 | 78 imc_counters_config[i][j].event; 79 imc_counters_config[i][j].pe.sample_type = PERF_SAMPLE_IDENTIFIER; 80 imc_counters_config[i][j].pe.read_format = 81 PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING; 82 } 83 84 void membw_ioctl_perf_event_ioc_reset_enable(int i, int j) 85 { 86 ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_RESET, 0); 87 ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_ENABLE, 0); 88 } 89 90 void membw_ioctl_perf_event_ioc_disable(int i, int j) 91 { 92 ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_DISABLE, 0); 93 } 94 95 /* 96 * get_event_and_umask: Parse config into event and umask 97 * @cas_count_cfg: Config 98 * @count: iMC number 99 * @op: Operation (read/write) 100 */ 101 void get_event_and_umask(char *cas_count_cfg, int count, bool op) 102 { 103 char *token[MAX_TOKENS]; 104 int i = 0; 105 106 strcat(cas_count_cfg, ","); 107 token[0] = strtok(cas_count_cfg, "=,"); 108 109 for (i = 1; i < MAX_TOKENS; i++) 110 token[i] = strtok(NULL, "=,"); 111 112 for (i = 0; i < MAX_TOKENS; i++) { 113 if (!token[i]) 114 break; 115 if (strcmp(token[i], "event") == 0) { 116 if (op == READ) 117 imc_counters_config[count][READ].event = 118 strtol(token[i + 1], NULL, 16); 119 else 120 imc_counters_config[count][WRITE].event = 121 strtol(token[i + 1], NULL, 16); 122 } 123 if (strcmp(token[i], "umask") == 0) { 124 if (op == READ) 125 imc_counters_config[count][READ].umask = 126 strtol(token[i + 1], NULL, 16); 127 else 128 imc_counters_config[count][WRITE].umask = 129 strtol(token[i + 1], NULL, 16); 130 } 131 } 132 } 133 134 static int open_perf_event(int i, int cpu_no, int j) 135 { 136 imc_counters_config[i][j].fd = 137 perf_event_open(&imc_counters_config[i][j].pe, -1, cpu_no, -1, 138 PERF_FLAG_FD_CLOEXEC); 139 140 if (imc_counters_config[i][j].fd == -1) { 141 fprintf(stderr, "Error opening leader %llx\n", 142 imc_counters_config[i][j].pe.config); 143 144 return -1; 145 } 146 147 return 0; 148 } 149 150 /* Get type and config (read and write) of an iMC counter */ 151 static int read_from_imc_dir(char *imc_dir, int count) 152 { 153 char cas_count_cfg[1024], imc_counter_cfg[1024], imc_counter_type[1024]; 154 FILE *fp; 155 156 /* Get type of iMC counter */ 157 sprintf(imc_counter_type, "%s%s", imc_dir, "type"); 158 fp = fopen(imc_counter_type, "r"); 159 if (!fp) { 160 ksft_perror("Failed to open iMC counter type file"); 161 162 return -1; 163 } 164 if (fscanf(fp, "%u", &imc_counters_config[count][READ].type) <= 0) { 165 ksft_perror("Could not get iMC type"); 166 fclose(fp); 167 168 return -1; 169 } 170 fclose(fp); 171 172 imc_counters_config[count][WRITE].type = 173 imc_counters_config[count][READ].type; 174 175 /* Get read config */ 176 sprintf(imc_counter_cfg, "%s%s", imc_dir, READ_FILE_NAME); 177 fp = fopen(imc_counter_cfg, "r"); 178 if (!fp) { 179 ksft_perror("Failed to open iMC config file"); 180 181 return -1; 182 } 183 if (fscanf(fp, "%s", cas_count_cfg) <= 0) { 184 ksft_perror("Could not get iMC cas count read"); 185 fclose(fp); 186 187 return -1; 188 } 189 fclose(fp); 190 191 get_event_and_umask(cas_count_cfg, count, READ); 192 193 /* Get write config */ 194 sprintf(imc_counter_cfg, "%s%s", imc_dir, WRITE_FILE_NAME); 195 fp = fopen(imc_counter_cfg, "r"); 196 if (!fp) { 197 ksft_perror("Failed to open iMC config file"); 198 199 return -1; 200 } 201 if (fscanf(fp, "%s", cas_count_cfg) <= 0) { 202 ksft_perror("Could not get iMC cas count write"); 203 fclose(fp); 204 205 return -1; 206 } 207 fclose(fp); 208 209 get_event_and_umask(cas_count_cfg, count, WRITE); 210 211 return 0; 212 } 213 214 /* 215 * A system can have 'n' number of iMC (Integrated Memory Controller) 216 * counters, get that 'n'. For each iMC counter get it's type and config. 217 * Also, each counter has two configs, one for read and the other for write. 218 * A config again has two parts, event and umask. 219 * Enumerate all these details into an array of structures. 220 * 221 * Return: >= 0 on success. < 0 on failure. 222 */ 223 static int num_of_imcs(void) 224 { 225 char imc_dir[512], *temp; 226 unsigned int count = 0; 227 struct dirent *ep; 228 int ret; 229 DIR *dp; 230 231 dp = opendir(DYN_PMU_PATH); 232 if (dp) { 233 while ((ep = readdir(dp))) { 234 temp = strstr(ep->d_name, UNCORE_IMC); 235 if (!temp) 236 continue; 237 238 /* 239 * imc counters are named as "uncore_imc_<n>", hence 240 * increment the pointer to point to <n>. Note that 241 * sizeof(UNCORE_IMC) would count for null character as 242 * well and hence the last underscore character in 243 * uncore_imc'_' need not be counted. 244 */ 245 temp = temp + sizeof(UNCORE_IMC); 246 247 /* 248 * Some directories under "DYN_PMU_PATH" could have 249 * names like "uncore_imc_free_running", hence, check if 250 * first character is a numerical digit or not. 251 */ 252 if (temp[0] >= '0' && temp[0] <= '9') { 253 sprintf(imc_dir, "%s/%s/", DYN_PMU_PATH, 254 ep->d_name); 255 ret = read_from_imc_dir(imc_dir, count); 256 if (ret) { 257 closedir(dp); 258 259 return ret; 260 } 261 count++; 262 } 263 } 264 closedir(dp); 265 if (count == 0) { 266 ksft_print_msg("Unable to find iMC counters\n"); 267 268 return -1; 269 } 270 } else { 271 ksft_perror("Unable to open PMU directory"); 272 273 return -1; 274 } 275 276 return count; 277 } 278 279 static int initialize_mem_bw_imc(void) 280 { 281 int imc, j; 282 283 imcs = num_of_imcs(); 284 if (imcs <= 0) 285 return imcs; 286 287 /* Initialize perf_event_attr structures for all iMC's */ 288 for (imc = 0; imc < imcs; imc++) { 289 for (j = 0; j < 2; j++) 290 membw_initialize_perf_event_attr(imc, j); 291 } 292 293 return 0; 294 } 295 296 /* 297 * get_mem_bw_imc: Memory band width as reported by iMC counters 298 * @cpu_no: CPU number that the benchmark PID is binded to 299 * @bw_report: Bandwidth report type (reads, writes) 300 * 301 * Memory B/W utilized by a process on a socket can be calculated using 302 * iMC counters. Perf events are used to read these counters. 303 * 304 * Return: = 0 on success. < 0 on failure. 305 */ 306 static int get_mem_bw_imc(int cpu_no, char *bw_report, float *bw_imc) 307 { 308 float reads, writes, of_mul_read, of_mul_write; 309 int imc, j, ret; 310 311 /* Start all iMC counters to log values (both read and write) */ 312 reads = 0, writes = 0, of_mul_read = 1, of_mul_write = 1; 313 for (imc = 0; imc < imcs; imc++) { 314 for (j = 0; j < 2; j++) { 315 ret = open_perf_event(imc, cpu_no, j); 316 if (ret) 317 return -1; 318 } 319 for (j = 0; j < 2; j++) 320 membw_ioctl_perf_event_ioc_reset_enable(imc, j); 321 } 322 323 sleep(1); 324 325 /* Stop counters after a second to get results (both read and write) */ 326 for (imc = 0; imc < imcs; imc++) { 327 for (j = 0; j < 2; j++) 328 membw_ioctl_perf_event_ioc_disable(imc, j); 329 } 330 331 /* 332 * Get results which are stored in struct type imc_counter_config 333 * Take over flow into consideration before calculating total b/w 334 */ 335 for (imc = 0; imc < imcs; imc++) { 336 struct imc_counter_config *r = 337 &imc_counters_config[imc][READ]; 338 struct imc_counter_config *w = 339 &imc_counters_config[imc][WRITE]; 340 341 if (read(r->fd, &r->return_value, 342 sizeof(struct membw_read_format)) == -1) { 343 ksft_perror("Couldn't get read b/w through iMC"); 344 345 return -1; 346 } 347 348 if (read(w->fd, &w->return_value, 349 sizeof(struct membw_read_format)) == -1) { 350 ksft_perror("Couldn't get write bw through iMC"); 351 352 return -1; 353 } 354 355 __u64 r_time_enabled = r->return_value.time_enabled; 356 __u64 r_time_running = r->return_value.time_running; 357 358 if (r_time_enabled != r_time_running) 359 of_mul_read = (float)r_time_enabled / 360 (float)r_time_running; 361 362 __u64 w_time_enabled = w->return_value.time_enabled; 363 __u64 w_time_running = w->return_value.time_running; 364 365 if (w_time_enabled != w_time_running) 366 of_mul_write = (float)w_time_enabled / 367 (float)w_time_running; 368 reads += r->return_value.value * of_mul_read * SCALE; 369 writes += w->return_value.value * of_mul_write * SCALE; 370 } 371 372 for (imc = 0; imc < imcs; imc++) { 373 close(imc_counters_config[imc][READ].fd); 374 close(imc_counters_config[imc][WRITE].fd); 375 } 376 377 if (strcmp(bw_report, "reads") == 0) { 378 *bw_imc = reads; 379 return 0; 380 } 381 382 if (strcmp(bw_report, "writes") == 0) { 383 *bw_imc = writes; 384 return 0; 385 } 386 387 *bw_imc = reads + writes; 388 return 0; 389 } 390 391 void set_mbm_path(const char *ctrlgrp, const char *mongrp, int domain_id) 392 { 393 if (ctrlgrp && mongrp) 394 sprintf(mbm_total_path, CON_MON_MBM_LOCAL_BYTES_PATH, 395 RESCTRL_PATH, ctrlgrp, mongrp, domain_id); 396 else if (!ctrlgrp && mongrp) 397 sprintf(mbm_total_path, MON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, 398 mongrp, domain_id); 399 else if (ctrlgrp && !mongrp) 400 sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, 401 ctrlgrp, domain_id); 402 else if (!ctrlgrp && !mongrp) 403 sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, 404 domain_id); 405 } 406 407 /* 408 * initialize_mem_bw_resctrl: Appropriately populate "mbm_total_path" 409 * @ctrlgrp: Name of the control monitor group (con_mon grp) 410 * @mongrp: Name of the monitor group (mon grp) 411 * @cpu_no: CPU number that the benchmark PID is binded to 412 * @resctrl_val: Resctrl feature (Eg: mbm, mba.. etc) 413 */ 414 static void initialize_mem_bw_resctrl(const char *ctrlgrp, const char *mongrp, 415 int cpu_no, char *resctrl_val) 416 { 417 int domain_id; 418 419 if (get_domain_id("MB", cpu_no, &domain_id) < 0) { 420 ksft_print_msg("Could not get domain ID\n"); 421 return; 422 } 423 424 if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) 425 set_mbm_path(ctrlgrp, mongrp, domain_id); 426 427 if (!strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) { 428 if (ctrlgrp) 429 sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, 430 RESCTRL_PATH, ctrlgrp, domain_id); 431 else 432 sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH, 433 RESCTRL_PATH, domain_id); 434 } 435 } 436 437 /* 438 * Get MBM Local bytes as reported by resctrl FS 439 * For MBM, 440 * 1. If con_mon grp and mon grp are given, then read from con_mon grp's mon grp 441 * 2. If only con_mon grp is given, then read from con_mon grp 442 * 3. If both are not given, then read from root con_mon grp 443 * For MBA, 444 * 1. If con_mon grp is given, then read from it 445 * 2. If con_mon grp is not given, then read from root con_mon grp 446 */ 447 static int get_mem_bw_resctrl(unsigned long *mbm_total) 448 { 449 FILE *fp; 450 451 fp = fopen(mbm_total_path, "r"); 452 if (!fp) { 453 ksft_perror("Failed to open total bw file"); 454 455 return -1; 456 } 457 if (fscanf(fp, "%lu", mbm_total) <= 0) { 458 ksft_perror("Could not get mbm local bytes"); 459 fclose(fp); 460 461 return -1; 462 } 463 fclose(fp); 464 465 return 0; 466 } 467 468 pid_t bm_pid, ppid; 469 470 void ctrlc_handler(int signum, siginfo_t *info, void *ptr) 471 { 472 /* Only kill child after bm_pid is set after fork() */ 473 if (bm_pid) 474 kill(bm_pid, SIGKILL); 475 umount_resctrlfs(); 476 if (current_test && current_test->cleanup) 477 current_test->cleanup(); 478 ksft_print_msg("Ending\n\n"); 479 480 exit(EXIT_SUCCESS); 481 } 482 483 /* 484 * Register CTRL-C handler for parent, as it has to kill 485 * child process before exiting. 486 */ 487 int signal_handler_register(const struct resctrl_test *test) 488 { 489 struct sigaction sigact = {}; 490 int ret = 0; 491 492 bm_pid = 0; 493 494 current_test = test; 495 sigact.sa_sigaction = ctrlc_handler; 496 sigemptyset(&sigact.sa_mask); 497 sigact.sa_flags = SA_SIGINFO; 498 if (sigaction(SIGINT, &sigact, NULL) || 499 sigaction(SIGTERM, &sigact, NULL) || 500 sigaction(SIGHUP, &sigact, NULL)) { 501 ksft_perror("sigaction"); 502 ret = -1; 503 } 504 return ret; 505 } 506 507 /* 508 * Reset signal handler to SIG_DFL. 509 * Non-Value return because the caller should keep 510 * the error code of other path even if sigaction fails. 511 */ 512 void signal_handler_unregister(void) 513 { 514 struct sigaction sigact = {}; 515 516 current_test = NULL; 517 sigact.sa_handler = SIG_DFL; 518 sigemptyset(&sigact.sa_mask); 519 if (sigaction(SIGINT, &sigact, NULL) || 520 sigaction(SIGTERM, &sigact, NULL) || 521 sigaction(SIGHUP, &sigact, NULL)) { 522 ksft_perror("sigaction"); 523 } 524 } 525 526 /* 527 * print_results_bw: the memory bandwidth results are stored in a file 528 * @filename: file that stores the results 529 * @bm_pid: child pid that runs benchmark 530 * @bw_imc: perf imc counter value 531 * @bw_resc: memory bandwidth value 532 * 533 * Return: 0 on success, < 0 on error. 534 */ 535 static int print_results_bw(char *filename, int bm_pid, float bw_imc, 536 unsigned long bw_resc) 537 { 538 unsigned long diff = fabs(bw_imc - bw_resc); 539 FILE *fp; 540 541 if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) { 542 printf("Pid: %d \t Mem_BW_iMC: %f \t ", bm_pid, bw_imc); 543 printf("Mem_BW_resc: %lu \t Difference: %lu\n", bw_resc, diff); 544 } else { 545 fp = fopen(filename, "a"); 546 if (!fp) { 547 ksft_perror("Cannot open results file"); 548 549 return -1; 550 } 551 if (fprintf(fp, "Pid: %d \t Mem_BW_iMC: %f \t Mem_BW_resc: %lu \t Difference: %lu\n", 552 bm_pid, bw_imc, bw_resc, diff) <= 0) { 553 ksft_print_msg("Could not log results\n"); 554 fclose(fp); 555 556 return -1; 557 } 558 fclose(fp); 559 } 560 561 return 0; 562 } 563 564 static void set_cmt_path(const char *ctrlgrp, const char *mongrp, char sock_num) 565 { 566 if (strlen(ctrlgrp) && strlen(mongrp)) 567 sprintf(llc_occup_path, CON_MON_LCC_OCCUP_PATH, RESCTRL_PATH, 568 ctrlgrp, mongrp, sock_num); 569 else if (!strlen(ctrlgrp) && strlen(mongrp)) 570 sprintf(llc_occup_path, MON_LCC_OCCUP_PATH, RESCTRL_PATH, 571 mongrp, sock_num); 572 else if (strlen(ctrlgrp) && !strlen(mongrp)) 573 sprintf(llc_occup_path, CON_LCC_OCCUP_PATH, RESCTRL_PATH, 574 ctrlgrp, sock_num); 575 else if (!strlen(ctrlgrp) && !strlen(mongrp)) 576 sprintf(llc_occup_path, LCC_OCCUP_PATH, RESCTRL_PATH, sock_num); 577 } 578 579 /* 580 * initialize_llc_occu_resctrl: Appropriately populate "llc_occup_path" 581 * @ctrlgrp: Name of the control monitor group (con_mon grp) 582 * @mongrp: Name of the monitor group (mon grp) 583 * @cpu_no: CPU number that the benchmark PID is binded to 584 * @resctrl_val: Resctrl feature (Eg: cat, cmt.. etc) 585 */ 586 static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp, 587 int cpu_no, char *resctrl_val) 588 { 589 int domain_id; 590 591 if (get_domain_id("L3", cpu_no, &domain_id) < 0) { 592 ksft_print_msg("Could not get domain ID\n"); 593 return; 594 } 595 596 if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) 597 set_cmt_path(ctrlgrp, mongrp, domain_id); 598 } 599 600 static int measure_vals(const struct user_params *uparams, 601 struct resctrl_val_param *param, 602 unsigned long *bw_resc_start) 603 { 604 unsigned long bw_resc, bw_resc_end; 605 float bw_imc; 606 int ret; 607 608 /* 609 * Measure memory bandwidth from resctrl and from 610 * another source which is perf imc value or could 611 * be something else if perf imc event is not available. 612 * Compare the two values to validate resctrl value. 613 * It takes 1sec to measure the data. 614 */ 615 ret = get_mem_bw_imc(uparams->cpu, param->bw_report, &bw_imc); 616 if (ret < 0) 617 return ret; 618 619 ret = get_mem_bw_resctrl(&bw_resc_end); 620 if (ret < 0) 621 return ret; 622 623 bw_resc = (bw_resc_end - *bw_resc_start) / MB; 624 ret = print_results_bw(param->filename, bm_pid, bw_imc, bw_resc); 625 if (ret) 626 return ret; 627 628 *bw_resc_start = bw_resc_end; 629 630 return 0; 631 } 632 633 /* 634 * run_benchmark - Run a specified benchmark or fill_buf (default benchmark) 635 * in specified signal. Direct benchmark stdio to /dev/null. 636 * @signum: signal number 637 * @info: signal info 638 * @ucontext: user context in signal handling 639 */ 640 static void run_benchmark(int signum, siginfo_t *info, void *ucontext) 641 { 642 int operation, ret, memflush; 643 char **benchmark_cmd; 644 size_t span; 645 bool once; 646 FILE *fp; 647 648 benchmark_cmd = info->si_ptr; 649 650 /* 651 * Direct stdio of child to /dev/null, so that only parent writes to 652 * stdio (console) 653 */ 654 fp = freopen("/dev/null", "w", stdout); 655 if (!fp) { 656 ksft_perror("Unable to direct benchmark status to /dev/null"); 657 PARENT_EXIT(); 658 } 659 660 if (strcmp(benchmark_cmd[0], "fill_buf") == 0) { 661 /* Execute default fill_buf benchmark */ 662 span = strtoul(benchmark_cmd[1], NULL, 10); 663 memflush = atoi(benchmark_cmd[2]); 664 operation = atoi(benchmark_cmd[3]); 665 if (!strcmp(benchmark_cmd[4], "true")) { 666 once = true; 667 } else if (!strcmp(benchmark_cmd[4], "false")) { 668 once = false; 669 } else { 670 ksft_print_msg("Invalid once parameter\n"); 671 PARENT_EXIT(); 672 } 673 674 if (run_fill_buf(span, memflush, operation, once)) 675 fprintf(stderr, "Error in running fill buffer\n"); 676 } else { 677 /* Execute specified benchmark */ 678 ret = execvp(benchmark_cmd[0], benchmark_cmd); 679 if (ret) 680 ksft_perror("execvp"); 681 } 682 683 fclose(stdout); 684 ksft_print_msg("Unable to run specified benchmark\n"); 685 PARENT_EXIT(); 686 } 687 688 /* 689 * resctrl_val: execute benchmark and measure memory bandwidth on 690 * the benchmark 691 * @test: test information structure 692 * @uparams: user supplied parameters 693 * @benchmark_cmd: benchmark command and its arguments 694 * @param: parameters passed to resctrl_val() 695 * 696 * Return: 0 when the test was run, < 0 on error. 697 */ 698 int resctrl_val(const struct resctrl_test *test, 699 const struct user_params *uparams, 700 const char * const *benchmark_cmd, 701 struct resctrl_val_param *param) 702 { 703 char *resctrl_val = param->resctrl_val; 704 unsigned long bw_resc_start = 0; 705 struct sigaction sigact; 706 int ret = 0, pipefd[2]; 707 char pipe_message = 0; 708 union sigval value; 709 710 if (strcmp(param->filename, "") == 0) 711 sprintf(param->filename, "stdio"); 712 713 if (!strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR)) || 714 !strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) { 715 ret = validate_bw_report_request(param->bw_report); 716 if (ret) 717 return ret; 718 } 719 720 /* 721 * If benchmark wasn't successfully started by child, then child should 722 * kill parent, so save parent's pid 723 */ 724 ppid = getpid(); 725 726 if (pipe(pipefd)) { 727 ksft_perror("Unable to create pipe"); 728 729 return -1; 730 } 731 732 /* 733 * Fork to start benchmark, save child's pid so that it can be killed 734 * when needed 735 */ 736 fflush(stdout); 737 bm_pid = fork(); 738 if (bm_pid == -1) { 739 ksft_perror("Unable to fork"); 740 741 return -1; 742 } 743 744 if (bm_pid == 0) { 745 /* 746 * Mask all signals except SIGUSR1, parent uses SIGUSR1 to 747 * start benchmark 748 */ 749 sigfillset(&sigact.sa_mask); 750 sigdelset(&sigact.sa_mask, SIGUSR1); 751 752 sigact.sa_sigaction = run_benchmark; 753 sigact.sa_flags = SA_SIGINFO; 754 755 /* Register for "SIGUSR1" signal from parent */ 756 if (sigaction(SIGUSR1, &sigact, NULL)) { 757 ksft_perror("Can't register child for signal"); 758 PARENT_EXIT(); 759 } 760 761 /* Tell parent that child is ready */ 762 close(pipefd[0]); 763 pipe_message = 1; 764 if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) < 765 sizeof(pipe_message)) { 766 ksft_perror("Failed signaling parent process"); 767 close(pipefd[1]); 768 return -1; 769 } 770 close(pipefd[1]); 771 772 /* Suspend child until delivery of "SIGUSR1" from parent */ 773 sigsuspend(&sigact.sa_mask); 774 775 ksft_perror("Child is done"); 776 PARENT_EXIT(); 777 } 778 779 ksft_print_msg("Benchmark PID: %d\n", bm_pid); 780 781 /* 782 * The cast removes constness but nothing mutates benchmark_cmd within 783 * the context of this process. At the receiving process, it becomes 784 * argv, which is mutable, on exec() but that's after fork() so it 785 * doesn't matter for the process running the tests. 786 */ 787 value.sival_ptr = (void *)benchmark_cmd; 788 789 /* Taskset benchmark to specified cpu */ 790 ret = taskset_benchmark(bm_pid, uparams->cpu, NULL); 791 if (ret) 792 goto out; 793 794 /* Write benchmark to specified control&monitoring grp in resctrl FS */ 795 ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp, 796 resctrl_val); 797 if (ret) 798 goto out; 799 800 if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) || 801 !strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) { 802 ret = initialize_mem_bw_imc(); 803 if (ret) 804 goto out; 805 806 initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp, 807 uparams->cpu, resctrl_val); 808 } else if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) 809 initialize_llc_occu_resctrl(param->ctrlgrp, param->mongrp, 810 uparams->cpu, resctrl_val); 811 812 /* Parent waits for child to be ready. */ 813 close(pipefd[1]); 814 while (pipe_message != 1) { 815 if (read(pipefd[0], &pipe_message, sizeof(pipe_message)) < 816 sizeof(pipe_message)) { 817 ksft_perror("Failed reading message from child process"); 818 close(pipefd[0]); 819 goto out; 820 } 821 } 822 close(pipefd[0]); 823 824 /* Signal child to start benchmark */ 825 if (sigqueue(bm_pid, SIGUSR1, value) == -1) { 826 ksft_perror("sigqueue SIGUSR1 to child"); 827 ret = -1; 828 goto out; 829 } 830 831 /* Give benchmark enough time to fully run */ 832 sleep(1); 833 834 /* Test runs until the callback setup() tells the test to stop. */ 835 while (1) { 836 ret = param->setup(test, uparams, param); 837 if (ret == END_OF_TESTS) { 838 ret = 0; 839 break; 840 } 841 if (ret < 0) 842 break; 843 844 if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) || 845 !strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) { 846 ret = measure_vals(uparams, param, &bw_resc_start); 847 if (ret) 848 break; 849 } else if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) { 850 sleep(1); 851 ret = measure_llc_resctrl(param->filename, bm_pid); 852 if (ret) 853 break; 854 } 855 } 856 857 out: 858 kill(bm_pid, SIGKILL); 859 860 return ret; 861 } 862