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 46struct 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 53struct 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 62static char mbm_total_path[1024]; 63static int imcs; 64static struct imc_counter_config imc_counters_config[MAX_IMCS][2]; 65 66void 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 83void 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 89void 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 */ 100void 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 133static 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 */ 150static 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 ksft_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 ksft_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 ksft_perror("Failed to open iMC config file"); 179 180 return -1; 181 } 182 if (fscanf(fp, "%s", cas_count_cfg) <= 0) { 183 ksft_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 ksft_perror("Failed to open iMC config file"); 197 198 return -1; 199 } 200 if (fscanf(fp, "%s", cas_count_cfg) <= 0) { 201 ksft_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 */ 222static int num_of_imcs(void) 223{ 224 char imc_dir[512], *temp; 225 unsigned int count = 0; 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 temp = strstr(ep->d_name, UNCORE_IMC); 234 if (!temp) 235 continue; 236 237 /* 238 * imc counters are named as "uncore_imc_<n>", hence 239 * increment the pointer to point to <n>. Note that 240 * sizeof(UNCORE_IMC) would count for null character as 241 * well and hence the last underscore character in 242 * uncore_imc'_' need not be counted. 243 */ 244 temp = temp + sizeof(UNCORE_IMC); 245 246 /* 247 * Some directories under "DYN_PMU_PATH" could have 248 * names like "uncore_imc_free_running", hence, check if 249 * first character is a numerical digit or not. 250 */ 251 if (temp[0] >= '0' && temp[0] <= '9') { 252 sprintf(imc_dir, "%s/%s/", DYN_PMU_PATH, 253 ep->d_name); 254 ret = read_from_imc_dir(imc_dir, count); 255 if (ret) { 256 closedir(dp); 257 258 return ret; 259 } 260 count++; 261 } 262 } 263 closedir(dp); 264 if (count == 0) { 265 ksft_print_msg("Unable to find iMC counters\n"); 266 267 return -1; 268 } 269 } else { 270 ksft_perror("Unable to open PMU directory"); 271 272 return -1; 273 } 274 275 return count; 276} 277 278static int initialize_mem_bw_imc(void) 279{ 280 int imc, j; 281 282 imcs = num_of_imcs(); 283 if (imcs <= 0) 284 return imcs; 285 286 /* Initialize perf_event_attr structures for all iMC's */ 287 for (imc = 0; imc < imcs; imc++) { 288 for (j = 0; j < 2; j++) 289 membw_initialize_perf_event_attr(imc, j); 290 } 291 292 return 0; 293} 294 295/* 296 * get_mem_bw_imc: Memory band width as reported by iMC counters 297 * @cpu_no: CPU number that the benchmark PID is binded to 298 * @bw_report: Bandwidth report type (reads, writes) 299 * 300 * Memory B/W utilized by a process on a socket can be calculated using 301 * iMC counters. Perf events are used to read these counters. 302 * 303 * Return: = 0 on success. < 0 on failure. 304 */ 305static int get_mem_bw_imc(int cpu_no, char *bw_report, float *bw_imc) 306{ 307 float reads, writes, of_mul_read, of_mul_write; 308 int imc, j, ret; 309 310 /* Start all iMC counters to log values (both read and write) */ 311 reads = 0, writes = 0, of_mul_read = 1, of_mul_write = 1; 312 for (imc = 0; imc < imcs; imc++) { 313 for (j = 0; j < 2; j++) { 314 ret = open_perf_event(imc, cpu_no, j); 315 if (ret) 316 return -1; 317 } 318 for (j = 0; j < 2; j++) 319 membw_ioctl_perf_event_ioc_reset_enable(imc, j); 320 } 321 322 sleep(1); 323 324 /* Stop counters after a second to get results (both read and write) */ 325 for (imc = 0; imc < imcs; imc++) { 326 for (j = 0; j < 2; j++) 327 membw_ioctl_perf_event_ioc_disable(imc, j); 328 } 329 330 /* 331 * Get results which are stored in struct type imc_counter_config 332 * Take over flow into consideration before calculating total b/w 333 */ 334 for (imc = 0; imc < imcs; imc++) { 335 struct imc_counter_config *r = 336 &imc_counters_config[imc][READ]; 337 struct imc_counter_config *w = 338 &imc_counters_config[imc][WRITE]; 339 340 if (read(r->fd, &r->return_value, 341 sizeof(struct membw_read_format)) == -1) { 342 ksft_perror("Couldn't get read b/w through iMC"); 343 344 return -1; 345 } 346 347 if (read(w->fd, &w->return_value, 348 sizeof(struct membw_read_format)) == -1) { 349 ksft_perror("Couldn't get write bw through iMC"); 350 351 return -1; 352 } 353 354 __u64 r_time_enabled = r->return_value.time_enabled; 355 __u64 r_time_running = r->return_value.time_running; 356 357 if (r_time_enabled != r_time_running) 358 of_mul_read = (float)r_time_enabled / 359 (float)r_time_running; 360 361 __u64 w_time_enabled = w->return_value.time_enabled; 362 __u64 w_time_running = w->return_value.time_running; 363 364 if (w_time_enabled != w_time_running) 365 of_mul_write = (float)w_time_enabled / 366 (float)w_time_running; 367 reads += r->return_value.value * of_mul_read * SCALE; 368 writes += w->return_value.value * of_mul_write * SCALE; 369 } 370 371 for (imc = 0; imc < imcs; imc++) { 372 close(imc_counters_config[imc][READ].fd); 373 close(imc_counters_config[imc][WRITE].fd); 374 } 375 376 if (strcmp(bw_report, "reads") == 0) { 377 *bw_imc = reads; 378 return 0; 379 } 380 381 if (strcmp(bw_report, "writes") == 0) { 382 *bw_imc = writes; 383 return 0; 384 } 385 386 *bw_imc = reads + writes; 387 return 0; 388} 389 390void set_mbm_path(const char *ctrlgrp, const char *mongrp, int domain_id) 391{ 392 if (ctrlgrp && mongrp) 393 sprintf(mbm_total_path, CON_MON_MBM_LOCAL_BYTES_PATH, 394 RESCTRL_PATH, ctrlgrp, mongrp, domain_id); 395 else if (!ctrlgrp && mongrp) 396 sprintf(mbm_total_path, MON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, 397 mongrp, domain_id); 398 else if (ctrlgrp && !mongrp) 399 sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, 400 ctrlgrp, domain_id); 401 else if (!ctrlgrp && !mongrp) 402 sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, 403 domain_id); 404} 405 406/* 407 * initialize_mem_bw_resctrl: Appropriately populate "mbm_total_path" 408 * @ctrlgrp: Name of the control monitor group (con_mon grp) 409 * @mongrp: Name of the monitor group (mon grp) 410 * @cpu_no: CPU number that the benchmark PID is binded to 411 * @resctrl_val: Resctrl feature (Eg: mbm, mba.. etc) 412 */ 413static void initialize_mem_bw_resctrl(const char *ctrlgrp, const char *mongrp, 414 int cpu_no, char *resctrl_val) 415{ 416 int domain_id; 417 418 if (get_domain_id("MB", cpu_no, &domain_id) < 0) { 419 ksft_print_msg("Could not get domain ID\n"); 420 return; 421 } 422 423 if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) 424 set_mbm_path(ctrlgrp, mongrp, domain_id); 425 426 if (!strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) { 427 if (ctrlgrp) 428 sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, 429 RESCTRL_PATH, ctrlgrp, domain_id); 430 else 431 sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH, 432 RESCTRL_PATH, domain_id); 433 } 434} 435 436/* 437 * Get MBM Local bytes as reported by resctrl FS 438 * For MBM, 439 * 1. If con_mon grp and mon grp are given, then read from con_mon grp's mon grp 440 * 2. If only con_mon grp is given, then read from con_mon grp 441 * 3. If both are not given, then read from root con_mon grp 442 * For MBA, 443 * 1. If con_mon grp is given, then read from it 444 * 2. If con_mon grp is not given, then read from root con_mon grp 445 */ 446static int get_mem_bw_resctrl(unsigned long *mbm_total) 447{ 448 FILE *fp; 449 450 fp = fopen(mbm_total_path, "r"); 451 if (!fp) { 452 ksft_perror("Failed to open total bw file"); 453 454 return -1; 455 } 456 if (fscanf(fp, "%lu", mbm_total) <= 0) { 457 ksft_perror("Could not get mbm local bytes"); 458 fclose(fp); 459 460 return -1; 461 } 462 fclose(fp); 463 464 return 0; 465} 466 467pid_t bm_pid, ppid; 468 469void ctrlc_handler(int signum, siginfo_t *info, void *ptr) 470{ 471 /* Only kill child after bm_pid is set after fork() */ 472 if (bm_pid) 473 kill(bm_pid, SIGKILL); 474 umount_resctrlfs(); 475 tests_cleanup(); 476 ksft_print_msg("Ending\n\n"); 477 478 exit(EXIT_SUCCESS); 479} 480 481/* 482 * Register CTRL-C handler for parent, as it has to kill 483 * child process before exiting. 484 */ 485int signal_handler_register(void) 486{ 487 struct sigaction sigact = {}; 488 int ret = 0; 489 490 bm_pid = 0; 491 492 sigact.sa_sigaction = ctrlc_handler; 493 sigemptyset(&sigact.sa_mask); 494 sigact.sa_flags = SA_SIGINFO; 495 if (sigaction(SIGINT, &sigact, NULL) || 496 sigaction(SIGTERM, &sigact, NULL) || 497 sigaction(SIGHUP, &sigact, NULL)) { 498 ksft_perror("sigaction"); 499 ret = -1; 500 } 501 return ret; 502} 503 504/* 505 * Reset signal handler to SIG_DFL. 506 * Non-Value return because the caller should keep 507 * the error code of other path even if sigaction fails. 508 */ 509void signal_handler_unregister(void) 510{ 511 struct sigaction sigact = {}; 512 513 sigact.sa_handler = SIG_DFL; 514 sigemptyset(&sigact.sa_mask); 515 if (sigaction(SIGINT, &sigact, NULL) || 516 sigaction(SIGTERM, &sigact, NULL) || 517 sigaction(SIGHUP, &sigact, NULL)) { 518 ksft_perror("sigaction"); 519 } 520} 521 522/* 523 * print_results_bw: the memory bandwidth results are stored in a file 524 * @filename: file that stores the results 525 * @bm_pid: child pid that runs benchmark 526 * @bw_imc: perf imc counter value 527 * @bw_resc: memory bandwidth value 528 * 529 * Return: 0 on success, < 0 on error. 530 */ 531static int print_results_bw(char *filename, int bm_pid, float bw_imc, 532 unsigned long bw_resc) 533{ 534 unsigned long diff = fabs(bw_imc - bw_resc); 535 FILE *fp; 536 537 if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) { 538 printf("Pid: %d \t Mem_BW_iMC: %f \t ", bm_pid, bw_imc); 539 printf("Mem_BW_resc: %lu \t Difference: %lu\n", bw_resc, diff); 540 } else { 541 fp = fopen(filename, "a"); 542 if (!fp) { 543 ksft_perror("Cannot open results file"); 544 545 return -1; 546 } 547 if (fprintf(fp, "Pid: %d \t Mem_BW_iMC: %f \t Mem_BW_resc: %lu \t Difference: %lu\n", 548 bm_pid, bw_imc, bw_resc, diff) <= 0) { 549 ksft_print_msg("Could not log results\n"); 550 fclose(fp); 551 552 return -1; 553 } 554 fclose(fp); 555 } 556 557 return 0; 558} 559 560static void set_cmt_path(const char *ctrlgrp, const char *mongrp, char sock_num) 561{ 562 if (strlen(ctrlgrp) && strlen(mongrp)) 563 sprintf(llc_occup_path, CON_MON_LCC_OCCUP_PATH, RESCTRL_PATH, 564 ctrlgrp, mongrp, sock_num); 565 else if (!strlen(ctrlgrp) && strlen(mongrp)) 566 sprintf(llc_occup_path, MON_LCC_OCCUP_PATH, RESCTRL_PATH, 567 mongrp, sock_num); 568 else if (strlen(ctrlgrp) && !strlen(mongrp)) 569 sprintf(llc_occup_path, CON_LCC_OCCUP_PATH, RESCTRL_PATH, 570 ctrlgrp, sock_num); 571 else if (!strlen(ctrlgrp) && !strlen(mongrp)) 572 sprintf(llc_occup_path, LCC_OCCUP_PATH, RESCTRL_PATH, sock_num); 573} 574 575/* 576 * initialize_llc_occu_resctrl: Appropriately populate "llc_occup_path" 577 * @ctrlgrp: Name of the control monitor group (con_mon grp) 578 * @mongrp: Name of the monitor group (mon grp) 579 * @cpu_no: CPU number that the benchmark PID is binded to 580 * @resctrl_val: Resctrl feature (Eg: cat, cmt.. etc) 581 */ 582static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp, 583 int cpu_no, char *resctrl_val) 584{ 585 int domain_id; 586 587 if (get_domain_id("L3", cpu_no, &domain_id) < 0) { 588 ksft_print_msg("Could not get domain ID\n"); 589 return; 590 } 591 592 if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) 593 set_cmt_path(ctrlgrp, mongrp, domain_id); 594} 595 596static int measure_vals(const struct user_params *uparams, 597 struct resctrl_val_param *param, 598 unsigned long *bw_resc_start) 599{ 600 unsigned long bw_resc, bw_resc_end; 601 float bw_imc; 602 int ret; 603 604 /* 605 * Measure memory bandwidth from resctrl and from 606 * another source which is perf imc value or could 607 * be something else if perf imc event is not available. 608 * Compare the two values to validate resctrl value. 609 * It takes 1sec to measure the data. 610 */ 611 ret = get_mem_bw_imc(uparams->cpu, param->bw_report, &bw_imc); 612 if (ret < 0) 613 return ret; 614 615 ret = get_mem_bw_resctrl(&bw_resc_end); 616 if (ret < 0) 617 return ret; 618 619 bw_resc = (bw_resc_end - *bw_resc_start) / MB; 620 ret = print_results_bw(param->filename, bm_pid, bw_imc, bw_resc); 621 if (ret) 622 return ret; 623 624 *bw_resc_start = bw_resc_end; 625 626 return 0; 627} 628 629/* 630 * run_benchmark - Run a specified benchmark or fill_buf (default benchmark) 631 * in specified signal. Direct benchmark stdio to /dev/null. 632 * @signum: signal number 633 * @info: signal info 634 * @ucontext: user context in signal handling 635 */ 636static void run_benchmark(int signum, siginfo_t *info, void *ucontext) 637{ 638 int operation, ret, memflush; 639 char **benchmark_cmd; 640 size_t span; 641 bool once; 642 FILE *fp; 643 644 benchmark_cmd = info->si_ptr; 645 646 /* 647 * Direct stdio of child to /dev/null, so that only parent writes to 648 * stdio (console) 649 */ 650 fp = freopen("/dev/null", "w", stdout); 651 if (!fp) { 652 ksft_perror("Unable to direct benchmark status to /dev/null"); 653 PARENT_EXIT(); 654 } 655 656 if (strcmp(benchmark_cmd[0], "fill_buf") == 0) { 657 /* Execute default fill_buf benchmark */ 658 span = strtoul(benchmark_cmd[1], NULL, 10); 659 memflush = atoi(benchmark_cmd[2]); 660 operation = atoi(benchmark_cmd[3]); 661 if (!strcmp(benchmark_cmd[4], "true")) { 662 once = true; 663 } else if (!strcmp(benchmark_cmd[4], "false")) { 664 once = false; 665 } else { 666 ksft_print_msg("Invalid once parameter\n"); 667 PARENT_EXIT(); 668 } 669 670 if (run_fill_buf(span, memflush, operation, once)) 671 fprintf(stderr, "Error in running fill buffer\n"); 672 } else { 673 /* Execute specified benchmark */ 674 ret = execvp(benchmark_cmd[0], benchmark_cmd); 675 if (ret) 676 ksft_perror("execvp"); 677 } 678 679 fclose(stdout); 680 ksft_print_msg("Unable to run specified benchmark\n"); 681 PARENT_EXIT(); 682} 683 684/* 685 * resctrl_val: execute benchmark and measure memory bandwidth on 686 * the benchmark 687 * @test: test information structure 688 * @uparams: user supplied parameters 689 * @benchmark_cmd: benchmark command and its arguments 690 * @param: parameters passed to resctrl_val() 691 * 692 * Return: 0 when the test was run, < 0 on error. 693 */ 694int resctrl_val(const struct resctrl_test *test, 695 const struct user_params *uparams, 696 const char * const *benchmark_cmd, 697 struct resctrl_val_param *param) 698{ 699 char *resctrl_val = param->resctrl_val; 700 unsigned long bw_resc_start = 0; 701 struct sigaction sigact; 702 int ret = 0, pipefd[2]; 703 char pipe_message = 0; 704 union sigval value; 705 706 if (strcmp(param->filename, "") == 0) 707 sprintf(param->filename, "stdio"); 708 709 if (!strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR)) || 710 !strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) { 711 ret = validate_bw_report_request(param->bw_report); 712 if (ret) 713 return ret; 714 } 715 716 /* 717 * If benchmark wasn't successfully started by child, then child should 718 * kill parent, so save parent's pid 719 */ 720 ppid = getpid(); 721 722 if (pipe(pipefd)) { 723 ksft_perror("Unable to create pipe"); 724 725 return -1; 726 } 727 728 /* 729 * Fork to start benchmark, save child's pid so that it can be killed 730 * when needed 731 */ 732 fflush(stdout); 733 bm_pid = fork(); 734 if (bm_pid == -1) { 735 ksft_perror("Unable to fork"); 736 737 return -1; 738 } 739 740 if (bm_pid == 0) { 741 /* 742 * Mask all signals except SIGUSR1, parent uses SIGUSR1 to 743 * start benchmark 744 */ 745 sigfillset(&sigact.sa_mask); 746 sigdelset(&sigact.sa_mask, SIGUSR1); 747 748 sigact.sa_sigaction = run_benchmark; 749 sigact.sa_flags = SA_SIGINFO; 750 751 /* Register for "SIGUSR1" signal from parent */ 752 if (sigaction(SIGUSR1, &sigact, NULL)) { 753 ksft_perror("Can't register child for signal"); 754 PARENT_EXIT(); 755 } 756 757 /* Tell parent that child is ready */ 758 close(pipefd[0]); 759 pipe_message = 1; 760 if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) < 761 sizeof(pipe_message)) { 762 ksft_perror("Failed signaling parent process"); 763 close(pipefd[1]); 764 return -1; 765 } 766 close(pipefd[1]); 767 768 /* Suspend child until delivery of "SIGUSR1" from parent */ 769 sigsuspend(&sigact.sa_mask); 770 771 ksft_perror("Child is done"); 772 PARENT_EXIT(); 773 } 774 775 ksft_print_msg("Benchmark PID: %d\n", bm_pid); 776 777 /* 778 * The cast removes constness but nothing mutates benchmark_cmd within 779 * the context of this process. At the receiving process, it becomes 780 * argv, which is mutable, on exec() but that's after fork() so it 781 * doesn't matter for the process running the tests. 782 */ 783 value.sival_ptr = (void *)benchmark_cmd; 784 785 /* Taskset benchmark to specified cpu */ 786 ret = taskset_benchmark(bm_pid, uparams->cpu, NULL); 787 if (ret) 788 goto out; 789 790 /* Write benchmark to specified control&monitoring grp in resctrl FS */ 791 ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp, 792 resctrl_val); 793 if (ret) 794 goto out; 795 796 if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) || 797 !strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) { 798 ret = initialize_mem_bw_imc(); 799 if (ret) 800 goto out; 801 802 initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp, 803 uparams->cpu, resctrl_val); 804 } else if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) 805 initialize_llc_occu_resctrl(param->ctrlgrp, param->mongrp, 806 uparams->cpu, resctrl_val); 807 808 /* Parent waits for child to be ready. */ 809 close(pipefd[1]); 810 while (pipe_message != 1) { 811 if (read(pipefd[0], &pipe_message, sizeof(pipe_message)) < 812 sizeof(pipe_message)) { 813 ksft_perror("Failed reading message from child process"); 814 close(pipefd[0]); 815 goto out; 816 } 817 } 818 close(pipefd[0]); 819 820 /* Signal child to start benchmark */ 821 if (sigqueue(bm_pid, SIGUSR1, value) == -1) { 822 ksft_perror("sigqueue SIGUSR1 to child"); 823 ret = -1; 824 goto out; 825 } 826 827 /* Give benchmark enough time to fully run */ 828 sleep(1); 829 830 /* Test runs until the callback setup() tells the test to stop. */ 831 while (1) { 832 ret = param->setup(test, uparams, param); 833 if (ret == END_OF_TESTS) { 834 ret = 0; 835 break; 836 } 837 if (ret < 0) 838 break; 839 840 if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) || 841 !strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) { 842 ret = measure_vals(uparams, param, &bw_resc_start); 843 if (ret) 844 break; 845 } else if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) { 846 sleep(1); 847 ret = measure_llc_resctrl(param->filename, bm_pid); 848 if (ret) 849 break; 850 } 851 } 852 853out: 854 kill(bm_pid, SIGKILL); 855 856 return ret; 857} 858