tools/testing/selftests/resctrl/resctrl_val.c

   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 }