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 66 void membw_initialize_perf_event_attr(int i, int j) 67 { 68 memset(&imc_counters_config[i][j].pe, 0, 69 sizeof(struct perf_event_attr)); 70 imc_counters_config[i][j].pe.type = imc_counters_config[i][j].type; 71 imc_counters_config[i][j].pe.size = sizeof(struct perf_event_attr); 72 imc_counters_config[i][j].pe.disabled = 1; 73 imc_counters_config[i][j].pe.inherit = 1; 74 imc_counters_config[i][j].pe.exclude_guest = 0; 75 imc_counters_config[i][j].pe.config = 76 imc_counters_config[i][j].umask << 8 | 77 imc_counters_config[i][j].event; 78 imc_counters_config[i][j].pe.sample_type = PERF_SAMPLE_IDENTIFIER; 79 imc_counters_config[i][j].pe.read_format = 80 PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING; 81 } 82 83 void membw_ioctl_perf_event_ioc_reset_enable(int i, int j) 84 { 85 ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_RESET, 0); 86 ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_ENABLE, 0); 87 } 88 89 void membw_ioctl_perf_event_ioc_disable(int i, int j) 90 { 91 ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_DISABLE, 0); 92 } 93 94 /* 95 * get_event_and_umask: Parse config into event and umask 96 * @cas_count_cfg: Config 97 * @count: iMC number 98 * @op: Operation (read/write) 99 */ 100 void get_event_and_umask(char *cas_count_cfg, int count, bool op) 101 { 102 char *token[MAX_TOKENS]; 103 int i = 0; 104 105 strcat(cas_count_cfg, ","); 106 token[0] = strtok(cas_count_cfg, "=,"); 107 108 for (i = 1; i < MAX_TOKENS; i++) 109 token[i] = strtok(NULL, "=,"); 110 111 for (i = 0; i < MAX_TOKENS; i++) { 112 if (!token[i]) 113 break; 114 if (strcmp(token[i], "event") == 0) { 115 if (op == READ) 116 imc_counters_config[count][READ].event = 117 strtol(token[i + 1], NULL, 16); 118 else 119 imc_counters_config[count][WRITE].event = 120 strtol(token[i + 1], NULL, 16); 121 } 122 if (strcmp(token[i], "umask") == 0) { 123 if (op == READ) 124 imc_counters_config[count][READ].umask = 125 strtol(token[i + 1], NULL, 16); 126 else 127 imc_counters_config[count][WRITE].umask = 128 strtol(token[i + 1], NULL, 16); 129 } 130 } 131 } 132 133 static int open_perf_event(int i, int cpu_no, int j) 134 { 135 imc_counters_config[i][j].fd = 136 perf_event_open(&imc_counters_config[i][j].pe, -1, cpu_no, -1, 137 PERF_FLAG_FD_CLOEXEC); 138 139 if (imc_counters_config[i][j].fd == -1) { 140 fprintf(stderr, "Error opening leader %llx\n", 141 imc_counters_config[i][j].pe.config); 142 143 return -1; 144 } 145 146 return 0; 147 } 148 149 /* Get type and config (read and write) of an iMC counter */ 150 static int read_from_imc_dir(char *imc_dir, int count) 151 { 152 char cas_count_cfg[1024], imc_counter_cfg[1024], imc_counter_type[1024]; 153 FILE *fp; 154 155 /* Get type of iMC counter */ 156 sprintf(imc_counter_type, "%s%s", imc_dir, "type"); 157 fp = fopen(imc_counter_type, "r"); 158 if (!fp) { 159 perror("Failed to open imc counter type file"); 160 161 return -1; 162 } 163 if (fscanf(fp, "%u", &imc_counters_config[count][READ].type) <= 0) { 164 perror("Could not get imc type"); 165 fclose(fp); 166 167 return -1; 168 } 169 fclose(fp); 170 171 imc_counters_config[count][WRITE].type = 172 imc_counters_config[count][READ].type; 173 174 /* Get read config */ 175 sprintf(imc_counter_cfg, "%s%s", imc_dir, READ_FILE_NAME); 176 fp = fopen(imc_counter_cfg, "r"); 177 if (!fp) { 178 perror("Failed to open imc config file"); 179 180 return -1; 181 } 182 if (fscanf(fp, "%s", cas_count_cfg) <= 0) { 183 perror("Could not get imc cas count read"); 184 fclose(fp); 185 186 return -1; 187 } 188 fclose(fp); 189 190 get_event_and_umask(cas_count_cfg, count, READ); 191 192 /* Get write config */ 193 sprintf(imc_counter_cfg, "%s%s", imc_dir, WRITE_FILE_NAME); 194 fp = fopen(imc_counter_cfg, "r"); 195 if (!fp) { 196 perror("Failed to open imc config file"); 197 198 return -1; 199 } 200 if (fscanf(fp, "%s", cas_count_cfg) <= 0) { 201 perror("Could not get imc cas count write"); 202 fclose(fp); 203 204 return -1; 205 } 206 fclose(fp); 207 208 get_event_and_umask(cas_count_cfg, count, WRITE); 209 210 return 0; 211 } 212 213 /* 214 * A system can have 'n' number of iMC (Integrated Memory Controller) 215 * counters, get that 'n'. For each iMC counter get it's type and config. 216 * Also, each counter has two configs, one for read and the other for write. 217 * A config again has two parts, event and umask. 218 * Enumerate all these details into an array of structures. 219 * 220 * Return: >= 0 on success. < 0 on failure. 221 */ 222 static int num_of_imcs(void) 223 { 224 unsigned int count = 0; 225 char imc_dir[512]; 226 struct dirent *ep; 227 int ret; 228 DIR *dp; 229 230 dp = opendir(DYN_PMU_PATH); 231 if (dp) { 232 while ((ep = readdir(dp))) { 233 if (strstr(ep->d_name, UNCORE_IMC)) { 234 sprintf(imc_dir, "%s/%s/", DYN_PMU_PATH, 235 ep->d_name); 236 ret = read_from_imc_dir(imc_dir, count); 237 if (ret) { 238 closedir(dp); 239 240 return ret; 241 } 242 count++; 243 } 244 } 245 closedir(dp); 246 if (count == 0) { 247 perror("Unable find iMC counters!\n"); 248 249 return -1; 250 } 251 } else { 252 perror("Unable to open PMU directory!\n"); 253 254 return -1; 255 } 256 257 return count; 258 } 259 260 static int initialize_mem_bw_imc(void) 261 { 262 int imc, j; 263 264 imcs = num_of_imcs(); 265 if (imcs <= 0) 266 return imcs; 267 268 /* Initialize perf_event_attr structures for all iMC's */ 269 for (imc = 0; imc < imcs; imc++) { 270 for (j = 0; j < 2; j++) 271 membw_initialize_perf_event_attr(imc, j); 272 } 273 274 return 0; 275 } 276 277 /* 278 * get_mem_bw_imc: Memory band width as reported by iMC counters 279 * @cpu_no: CPU number that the benchmark PID is binded to 280 * @bw_report: Bandwidth report type (reads, writes) 281 * 282 * Memory B/W utilized by a process on a socket can be calculated using 283 * iMC counters. Perf events are used to read these counters. 284 * 285 * Return: >= 0 on success. < 0 on failure. 286 */ 287 static float get_mem_bw_imc(int cpu_no, char *bw_report) 288 { 289 float reads, writes, of_mul_read, of_mul_write; 290 int imc, j, ret; 291 292 /* Start all iMC counters to log values (both read and write) */ 293 reads = 0, writes = 0, of_mul_read = 1, of_mul_write = 1; 294 for (imc = 0; imc < imcs; imc++) { 295 for (j = 0; j < 2; j++) { 296 ret = open_perf_event(imc, cpu_no, j); 297 if (ret) 298 return -1; 299 } 300 for (j = 0; j < 2; j++) 301 membw_ioctl_perf_event_ioc_reset_enable(imc, j); 302 } 303 304 sleep(1); 305 306 /* Stop counters after a second to get results (both read and write) */ 307 for (imc = 0; imc < imcs; imc++) { 308 for (j = 0; j < 2; j++) 309 membw_ioctl_perf_event_ioc_disable(imc, j); 310 } 311 312 /* 313 * Get results which are stored in struct type imc_counter_config 314 * Take over flow into consideration before calculating total b/w 315 */ 316 for (imc = 0; imc < imcs; imc++) { 317 struct imc_counter_config *r = 318 &imc_counters_config[imc][READ]; 319 struct imc_counter_config *w = 320 &imc_counters_config[imc][WRITE]; 321 322 if (read(r->fd, &r->return_value, 323 sizeof(struct membw_read_format)) == -1) { 324 perror("Couldn't get read b/w through iMC"); 325 326 return -1; 327 } 328 329 if (read(w->fd, &w->return_value, 330 sizeof(struct membw_read_format)) == -1) { 331 perror("Couldn't get write bw through iMC"); 332 333 return -1; 334 } 335 336 __u64 r_time_enabled = r->return_value.time_enabled; 337 __u64 r_time_running = r->return_value.time_running; 338 339 if (r_time_enabled != r_time_running) 340 of_mul_read = (float)r_time_enabled / 341 (float)r_time_running; 342 343 __u64 w_time_enabled = w->return_value.time_enabled; 344 __u64 w_time_running = w->return_value.time_running; 345 346 if (w_time_enabled != w_time_running) 347 of_mul_write = (float)w_time_enabled / 348 (float)w_time_running; 349 reads += r->return_value.value * of_mul_read * SCALE; 350 writes += w->return_value.value * of_mul_write * SCALE; 351 } 352 353 for (imc = 0; imc < imcs; imc++) { 354 close(imc_counters_config[imc][READ].fd); 355 close(imc_counters_config[imc][WRITE].fd); 356 } 357 358 if (strcmp(bw_report, "reads") == 0) 359 return reads; 360 361 if (strcmp(bw_report, "writes") == 0) 362 return writes; 363 364 return (reads + writes); 365 } 366 367 void set_mbm_path(const char *ctrlgrp, const char *mongrp, int resource_id) 368 { 369 if (ctrlgrp && mongrp) 370 sprintf(mbm_total_path, CON_MON_MBM_LOCAL_BYTES_PATH, 371 RESCTRL_PATH, ctrlgrp, mongrp, resource_id); 372 else if (!ctrlgrp && mongrp) 373 sprintf(mbm_total_path, MON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, 374 mongrp, resource_id); 375 else if (ctrlgrp && !mongrp) 376 sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, 377 ctrlgrp, resource_id); 378 else if (!ctrlgrp && !mongrp) 379 sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, 380 resource_id); 381 } 382 383 /* 384 * initialize_mem_bw_resctrl: Appropriately populate "mbm_total_path" 385 * @ctrlgrp: Name of the control monitor group (con_mon grp) 386 * @mongrp: Name of the monitor group (mon grp) 387 * @cpu_no: CPU number that the benchmark PID is binded to 388 * @resctrl_val: Resctrl feature (Eg: mbm, mba.. etc) 389 */ 390 static void initialize_mem_bw_resctrl(const char *ctrlgrp, const char *mongrp, 391 int cpu_no, char *resctrl_val) 392 { 393 int resource_id; 394 395 if (get_resource_id(cpu_no, &resource_id) < 0) { 396 perror("Could not get resource_id"); 397 return; 398 } 399 400 if (strcmp(resctrl_val, "mbm") == 0) 401 set_mbm_path(ctrlgrp, mongrp, resource_id); 402 403 if ((strcmp(resctrl_val, "mba") == 0)) { 404 if (ctrlgrp) 405 sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, 406 RESCTRL_PATH, ctrlgrp, resource_id); 407 else 408 sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH, 409 RESCTRL_PATH, resource_id); 410 } 411 } 412 413 /* 414 * Get MBM Local bytes as reported by resctrl FS 415 * For MBM, 416 * 1. If con_mon grp and mon grp are given, then read from con_mon grp's mon grp 417 * 2. If only con_mon grp is given, then read from con_mon grp 418 * 3. If both are not given, then read from root con_mon grp 419 * For MBA, 420 * 1. If con_mon grp is given, then read from it 421 * 2. If con_mon grp is not given, then read from root con_mon grp 422 */ 423 static unsigned long get_mem_bw_resctrl(void) 424 { 425 unsigned long mbm_total = 0; 426 FILE *fp; 427 428 fp = fopen(mbm_total_path, "r"); 429 if (!fp) { 430 perror("Failed to open total bw file"); 431 432 return -1; 433 } 434 if (fscanf(fp, "%lu", &mbm_total) <= 0) { 435 perror("Could not get mbm local bytes"); 436 fclose(fp); 437 438 return -1; 439 } 440 fclose(fp); 441 442 return mbm_total; 443 } 444 445 pid_t bm_pid, ppid; 446 447 void ctrlc_handler(int signum, siginfo_t *info, void *ptr) 448 { 449 kill(bm_pid, SIGKILL); 450 umount_resctrlfs(); 451 tests_cleanup(); 452 printf("Ending\n\n"); 453 454 exit(EXIT_SUCCESS); 455 } 456 457 /* 458 * print_results_bw: the memory bandwidth results are stored in a file 459 * @filename: file that stores the results 460 * @bm_pid: child pid that runs benchmark 461 * @bw_imc: perf imc counter value 462 * @bw_resc: memory bandwidth value 463 * 464 * Return: 0 on success. non-zero on failure. 465 */ 466 static int print_results_bw(char *filename, int bm_pid, float bw_imc, 467 unsigned long bw_resc) 468 { 469 unsigned long diff = fabs(bw_imc - bw_resc); 470 FILE *fp; 471 472 if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) { 473 printf("Pid: %d \t Mem_BW_iMC: %f \t ", bm_pid, bw_imc); 474 printf("Mem_BW_resc: %lu \t Difference: %lu\n", bw_resc, diff); 475 } else { 476 fp = fopen(filename, "a"); 477 if (!fp) { 478 perror("Cannot open results file"); 479 480 return errno; 481 } 482 if (fprintf(fp, "Pid: %d \t Mem_BW_iMC: %f \t Mem_BW_resc: %lu \t Difference: %lu\n", 483 bm_pid, bw_imc, bw_resc, diff) <= 0) { 484 fclose(fp); 485 perror("Could not log results."); 486 487 return errno; 488 } 489 fclose(fp); 490 } 491 492 return 0; 493 } 494 495 static void set_cqm_path(const char *ctrlgrp, const char *mongrp, char sock_num) 496 { 497 if (strlen(ctrlgrp) && strlen(mongrp)) 498 sprintf(llc_occup_path, CON_MON_LCC_OCCUP_PATH, RESCTRL_PATH, 499 ctrlgrp, mongrp, sock_num); 500 else if (!strlen(ctrlgrp) && strlen(mongrp)) 501 sprintf(llc_occup_path, MON_LCC_OCCUP_PATH, RESCTRL_PATH, 502 mongrp, sock_num); 503 else if (strlen(ctrlgrp) && !strlen(mongrp)) 504 sprintf(llc_occup_path, CON_LCC_OCCUP_PATH, RESCTRL_PATH, 505 ctrlgrp, sock_num); 506 else if (!strlen(ctrlgrp) && !strlen(mongrp)) 507 sprintf(llc_occup_path, LCC_OCCUP_PATH, RESCTRL_PATH, sock_num); 508 } 509 510 /* 511 * initialize_llc_occu_resctrl: Appropriately populate "llc_occup_path" 512 * @ctrlgrp: Name of the control monitor group (con_mon grp) 513 * @mongrp: Name of the monitor group (mon grp) 514 * @cpu_no: CPU number that the benchmark PID is binded to 515 * @resctrl_val: Resctrl feature (Eg: cat, cqm.. etc) 516 */ 517 static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp, 518 int cpu_no, char *resctrl_val) 519 { 520 int resource_id; 521 522 if (get_resource_id(cpu_no, &resource_id) < 0) { 523 perror("# Unable to resource_id"); 524 return; 525 } 526 527 if (strcmp(resctrl_val, "cqm") == 0) 528 set_cqm_path(ctrlgrp, mongrp, resource_id); 529 } 530 531 static int 532 measure_vals(struct resctrl_val_param *param, unsigned long *bw_resc_start) 533 { 534 unsigned long bw_imc, bw_resc, bw_resc_end; 535 int ret; 536 537 /* 538 * Measure memory bandwidth from resctrl and from 539 * another source which is perf imc value or could 540 * be something else if perf imc event is not available. 541 * Compare the two values to validate resctrl value. 542 * It takes 1sec to measure the data. 543 */ 544 bw_imc = get_mem_bw_imc(param->cpu_no, param->bw_report); 545 if (bw_imc <= 0) 546 return bw_imc; 547 548 bw_resc_end = get_mem_bw_resctrl(); 549 if (bw_resc_end <= 0) 550 return bw_resc_end; 551 552 bw_resc = (bw_resc_end - *bw_resc_start) / MB; 553 ret = print_results_bw(param->filename, bm_pid, bw_imc, bw_resc); 554 if (ret) 555 return ret; 556 557 *bw_resc_start = bw_resc_end; 558 559 return 0; 560 } 561 562 /* 563 * resctrl_val: execute benchmark and measure memory bandwidth on 564 * the benchmark 565 * @benchmark_cmd: benchmark command and its arguments 566 * @param: parameters passed to resctrl_val() 567 * 568 * Return: 0 on success. non-zero on failure. 569 */ 570 int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param) 571 { 572 char *resctrl_val = param->resctrl_val; 573 unsigned long bw_resc_start = 0; 574 struct sigaction sigact; 575 int ret = 0, pipefd[2]; 576 char pipe_message = 0; 577 union sigval value; 578 579 if (strcmp(param->filename, "") == 0) 580 sprintf(param->filename, "stdio"); 581 582 if ((strcmp(resctrl_val, "mba")) == 0 || 583 (strcmp(resctrl_val, "mbm")) == 0) { 584 ret = validate_bw_report_request(param->bw_report); 585 if (ret) 586 return ret; 587 } 588 589 ret = remount_resctrlfs(param->mum_resctrlfs); 590 if (ret) 591 return ret; 592 593 /* 594 * If benchmark wasn't successfully started by child, then child should 595 * kill parent, so save parent's pid 596 */ 597 ppid = getpid(); 598 599 if (pipe(pipefd)) { 600 perror("# Unable to create pipe"); 601 602 return -1; 603 } 604 605 /* 606 * Fork to start benchmark, save child's pid so that it can be killed 607 * when needed 608 */ 609 bm_pid = fork(); 610 if (bm_pid == -1) { 611 perror("# Unable to fork"); 612 613 return -1; 614 } 615 616 if (bm_pid == 0) { 617 /* 618 * Mask all signals except SIGUSR1, parent uses SIGUSR1 to 619 * start benchmark 620 */ 621 sigfillset(&sigact.sa_mask); 622 sigdelset(&sigact.sa_mask, SIGUSR1); 623 624 sigact.sa_sigaction = run_benchmark; 625 sigact.sa_flags = SA_SIGINFO; 626 627 /* Register for "SIGUSR1" signal from parent */ 628 if (sigaction(SIGUSR1, &sigact, NULL)) 629 PARENT_EXIT("Can't register child for signal"); 630 631 /* Tell parent that child is ready */ 632 close(pipefd[0]); 633 pipe_message = 1; 634 if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) < 635 sizeof(pipe_message)) { 636 perror("# failed signaling parent process"); 637 close(pipefd[1]); 638 return -1; 639 } 640 close(pipefd[1]); 641 642 /* Suspend child until delivery of "SIGUSR1" from parent */ 643 sigsuspend(&sigact.sa_mask); 644 645 PARENT_EXIT("Child is done"); 646 } 647 648 printf("# benchmark PID: %d\n", bm_pid); 649 650 /* 651 * Register CTRL-C handler for parent, as it has to kill benchmark 652 * before exiting 653 */ 654 sigact.sa_sigaction = ctrlc_handler; 655 sigemptyset(&sigact.sa_mask); 656 sigact.sa_flags = SA_SIGINFO; 657 if (sigaction(SIGINT, &sigact, NULL) || 658 sigaction(SIGHUP, &sigact, NULL)) { 659 perror("# sigaction"); 660 ret = errno; 661 goto out; 662 } 663 664 value.sival_ptr = benchmark_cmd; 665 666 /* Taskset benchmark to specified cpu */ 667 ret = taskset_benchmark(bm_pid, param->cpu_no); 668 if (ret) 669 goto out; 670 671 /* Write benchmark to specified control&monitoring grp in resctrl FS */ 672 ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp, 673 resctrl_val); 674 if (ret) 675 goto out; 676 677 if ((strcmp(resctrl_val, "mbm") == 0) || 678 (strcmp(resctrl_val, "mba") == 0)) { 679 ret = initialize_mem_bw_imc(); 680 if (ret) 681 goto out; 682 683 initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp, 684 param->cpu_no, resctrl_val); 685 } else if (strcmp(resctrl_val, "cqm") == 0) 686 initialize_llc_occu_resctrl(param->ctrlgrp, param->mongrp, 687 param->cpu_no, resctrl_val); 688 689 /* Parent waits for child to be ready. */ 690 close(pipefd[1]); 691 while (pipe_message != 1) { 692 if (read(pipefd[0], &pipe_message, sizeof(pipe_message)) < 693 sizeof(pipe_message)) { 694 perror("# failed reading message from child process"); 695 close(pipefd[0]); 696 goto out; 697 } 698 } 699 close(pipefd[0]); 700 701 /* Signal child to start benchmark */ 702 if (sigqueue(bm_pid, SIGUSR1, value) == -1) { 703 perror("# sigqueue SIGUSR1 to child"); 704 ret = errno; 705 goto out; 706 } 707 708 /* Give benchmark enough time to fully run */ 709 sleep(1); 710 711 /* Test runs until the callback setup() tells the test to stop. */ 712 while (1) { 713 if ((strcmp(resctrl_val, "mbm") == 0) || 714 (strcmp(resctrl_val, "mba") == 0)) { 715 ret = param->setup(1, param); 716 if (ret) { 717 ret = 0; 718 break; 719 } 720 721 ret = measure_vals(param, &bw_resc_start); 722 if (ret) 723 break; 724 } else if (strcmp(resctrl_val, "cqm") == 0) { 725 ret = param->setup(1, param); 726 if (ret) { 727 ret = 0; 728 break; 729 } 730 sleep(1); 731 ret = measure_cache_vals(param, bm_pid); 732 if (ret) 733 break; 734 } else { 735 break; 736 } 737 } 738 739 out: 740 kill(bm_pid, SIGKILL); 741 umount_resctrlfs(); 742 743 return ret; 744 } 745