linux/tools/testing/selftests/resctrl/resctrl_val.c
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   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                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 */
 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                        perror("Unable find iMC counters!\n");
 266
 267                        return -1;
 268                }
 269        } else {
 270                perror("Unable to open PMU directory!\n");
 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                        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                        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 resource_id)
 391{
 392        if (ctrlgrp && mongrp)
 393                sprintf(mbm_total_path, CON_MON_MBM_LOCAL_BYTES_PATH,
 394                        RESCTRL_PATH, ctrlgrp, mongrp, resource_id);
 395        else if (!ctrlgrp && mongrp)
 396                sprintf(mbm_total_path, MON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH,
 397                        mongrp, resource_id);
 398        else if (ctrlgrp && !mongrp)
 399                sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH,
 400                        ctrlgrp, resource_id);
 401        else if (!ctrlgrp && !mongrp)
 402                sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH, RESCTRL_PATH,
 403                        resource_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 resource_id;
 417
 418        if (get_resource_id(cpu_no, &resource_id) < 0) {
 419                perror("Could not get resource_id");
 420                return;
 421        }
 422
 423        if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)))
 424                set_mbm_path(ctrlgrp, mongrp, resource_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, resource_id);
 430                else
 431                        sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH,
 432                                RESCTRL_PATH, resource_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                perror("Failed to open total bw file");
 453
 454                return -1;
 455        }
 456        if (fscanf(fp, "%lu", mbm_total) <= 0) {
 457                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        kill(bm_pid, SIGKILL);
 472        umount_resctrlfs();
 473        tests_cleanup();
 474        ksft_print_msg("Ending\n\n");
 475
 476        exit(EXIT_SUCCESS);
 477}
 478
 479/*
 480 * print_results_bw:    the memory bandwidth results are stored in a file
 481 * @filename:           file that stores the results
 482 * @bm_pid:             child pid that runs benchmark
 483 * @bw_imc:             perf imc counter value
 484 * @bw_resc:            memory bandwidth value
 485 *
 486 * Return:              0 on success. non-zero on failure.
 487 */
 488static int print_results_bw(char *filename,  int bm_pid, float bw_imc,
 489                            unsigned long bw_resc)
 490{
 491        unsigned long diff = fabs(bw_imc - bw_resc);
 492        FILE *fp;
 493
 494        if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {
 495                printf("Pid: %d \t Mem_BW_iMC: %f \t ", bm_pid, bw_imc);
 496                printf("Mem_BW_resc: %lu \t Difference: %lu\n", bw_resc, diff);
 497        } else {
 498                fp = fopen(filename, "a");
 499                if (!fp) {
 500                        perror("Cannot open results file");
 501
 502                        return errno;
 503                }
 504                if (fprintf(fp, "Pid: %d \t Mem_BW_iMC: %f \t Mem_BW_resc: %lu \t Difference: %lu\n",
 505                            bm_pid, bw_imc, bw_resc, diff) <= 0) {
 506                        fclose(fp);
 507                        perror("Could not log results.");
 508
 509                        return errno;
 510                }
 511                fclose(fp);
 512        }
 513
 514        return 0;
 515}
 516
 517static void set_cmt_path(const char *ctrlgrp, const char *mongrp, char sock_num)
 518{
 519        if (strlen(ctrlgrp) && strlen(mongrp))
 520                sprintf(llc_occup_path, CON_MON_LCC_OCCUP_PATH, RESCTRL_PATH,
 521                        ctrlgrp, mongrp, sock_num);
 522        else if (!strlen(ctrlgrp) && strlen(mongrp))
 523                sprintf(llc_occup_path, MON_LCC_OCCUP_PATH, RESCTRL_PATH,
 524                        mongrp, sock_num);
 525        else if (strlen(ctrlgrp) && !strlen(mongrp))
 526                sprintf(llc_occup_path, CON_LCC_OCCUP_PATH, RESCTRL_PATH,
 527                        ctrlgrp, sock_num);
 528        else if (!strlen(ctrlgrp) && !strlen(mongrp))
 529                sprintf(llc_occup_path, LCC_OCCUP_PATH, RESCTRL_PATH, sock_num);
 530}
 531
 532/*
 533 * initialize_llc_occu_resctrl: Appropriately populate "llc_occup_path"
 534 * @ctrlgrp:                    Name of the control monitor group (con_mon grp)
 535 * @mongrp:                     Name of the monitor group (mon grp)
 536 * @cpu_no:                     CPU number that the benchmark PID is binded to
 537 * @resctrl_val:                Resctrl feature (Eg: cat, cmt.. etc)
 538 */
 539static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp,
 540                                        int cpu_no, char *resctrl_val)
 541{
 542        int resource_id;
 543
 544        if (get_resource_id(cpu_no, &resource_id) < 0) {
 545                perror("# Unable to resource_id");
 546                return;
 547        }
 548
 549        if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)))
 550                set_cmt_path(ctrlgrp, mongrp, resource_id);
 551}
 552
 553static int
 554measure_vals(struct resctrl_val_param *param, unsigned long *bw_resc_start)
 555{
 556        unsigned long bw_resc, bw_resc_end;
 557        float bw_imc;
 558        int ret;
 559
 560        /*
 561         * Measure memory bandwidth from resctrl and from
 562         * another source which is perf imc value or could
 563         * be something else if perf imc event is not available.
 564         * Compare the two values to validate resctrl value.
 565         * It takes 1sec to measure the data.
 566         */
 567        ret = get_mem_bw_imc(param->cpu_no, param->bw_report, &bw_imc);
 568        if (ret < 0)
 569                return ret;
 570
 571        ret = get_mem_bw_resctrl(&bw_resc_end);
 572        if (ret < 0)
 573                return ret;
 574
 575        bw_resc = (bw_resc_end - *bw_resc_start) / MB;
 576        ret = print_results_bw(param->filename, bm_pid, bw_imc, bw_resc);
 577        if (ret)
 578                return ret;
 579
 580        *bw_resc_start = bw_resc_end;
 581
 582        return 0;
 583}
 584
 585/*
 586 * resctrl_val: execute benchmark and measure memory bandwidth on
 587 *                      the benchmark
 588 * @benchmark_cmd:      benchmark command and its arguments
 589 * @param:              parameters passed to resctrl_val()
 590 *
 591 * Return:              0 on success. non-zero on failure.
 592 */
 593int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
 594{
 595        char *resctrl_val = param->resctrl_val;
 596        unsigned long bw_resc_start = 0;
 597        struct sigaction sigact;
 598        int ret = 0, pipefd[2];
 599        char pipe_message = 0;
 600        union sigval value;
 601
 602        if (strcmp(param->filename, "") == 0)
 603                sprintf(param->filename, "stdio");
 604
 605        if (!strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR)) ||
 606            !strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) {
 607                ret = validate_bw_report_request(param->bw_report);
 608                if (ret)
 609                        return ret;
 610        }
 611
 612        ret = remount_resctrlfs(param->mum_resctrlfs);
 613        if (ret)
 614                return ret;
 615
 616        /*
 617         * If benchmark wasn't successfully started by child, then child should
 618         * kill parent, so save parent's pid
 619         */
 620        ppid = getpid();
 621
 622        if (pipe(pipefd)) {
 623                perror("# Unable to create pipe");
 624
 625                return -1;
 626        }
 627
 628        /*
 629         * Fork to start benchmark, save child's pid so that it can be killed
 630         * when needed
 631         */
 632        bm_pid = fork();
 633        if (bm_pid == -1) {
 634                perror("# Unable to fork");
 635
 636                return -1;
 637        }
 638
 639        if (bm_pid == 0) {
 640                /*
 641                 * Mask all signals except SIGUSR1, parent uses SIGUSR1 to
 642                 * start benchmark
 643                 */
 644                sigfillset(&sigact.sa_mask);
 645                sigdelset(&sigact.sa_mask, SIGUSR1);
 646
 647                sigact.sa_sigaction = run_benchmark;
 648                sigact.sa_flags = SA_SIGINFO;
 649
 650                /* Register for "SIGUSR1" signal from parent */
 651                if (sigaction(SIGUSR1, &sigact, NULL))
 652                        PARENT_EXIT("Can't register child for signal");
 653
 654                /* Tell parent that child is ready */
 655                close(pipefd[0]);
 656                pipe_message = 1;
 657                if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
 658                    sizeof(pipe_message)) {
 659                        perror("# failed signaling parent process");
 660                        close(pipefd[1]);
 661                        return -1;
 662                }
 663                close(pipefd[1]);
 664
 665                /* Suspend child until delivery of "SIGUSR1" from parent */
 666                sigsuspend(&sigact.sa_mask);
 667
 668                PARENT_EXIT("Child is done");
 669        }
 670
 671        ksft_print_msg("Benchmark PID: %d\n", bm_pid);
 672
 673        /*
 674         * Register CTRL-C handler for parent, as it has to kill benchmark
 675         * before exiting
 676         */
 677        sigact.sa_sigaction = ctrlc_handler;
 678        sigemptyset(&sigact.sa_mask);
 679        sigact.sa_flags = SA_SIGINFO;
 680        if (sigaction(SIGINT, &sigact, NULL) ||
 681            sigaction(SIGHUP, &sigact, NULL)) {
 682                perror("# sigaction");
 683                ret = errno;
 684                goto out;
 685        }
 686
 687        value.sival_ptr = benchmark_cmd;
 688
 689        /* Taskset benchmark to specified cpu */
 690        ret = taskset_benchmark(bm_pid, param->cpu_no);
 691        if (ret)
 692                goto out;
 693
 694        /* Write benchmark to specified control&monitoring grp in resctrl FS */
 695        ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp,
 696                                      resctrl_val);
 697        if (ret)
 698                goto out;
 699
 700        if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) ||
 701            !strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) {
 702                ret = initialize_mem_bw_imc();
 703                if (ret)
 704                        goto out;
 705
 706                initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp,
 707                                          param->cpu_no, resctrl_val);
 708        } else if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)))
 709                initialize_llc_occu_resctrl(param->ctrlgrp, param->mongrp,
 710                                            param->cpu_no, resctrl_val);
 711
 712        /* Parent waits for child to be ready. */
 713        close(pipefd[1]);
 714        while (pipe_message != 1) {
 715                if (read(pipefd[0], &pipe_message, sizeof(pipe_message)) <
 716                    sizeof(pipe_message)) {
 717                        perror("# failed reading message from child process");
 718                        close(pipefd[0]);
 719                        goto out;
 720                }
 721        }
 722        close(pipefd[0]);
 723
 724        /* Signal child to start benchmark */
 725        if (sigqueue(bm_pid, SIGUSR1, value) == -1) {
 726                perror("# sigqueue SIGUSR1 to child");
 727                ret = errno;
 728                goto out;
 729        }
 730
 731        /* Give benchmark enough time to fully run */
 732        sleep(1);
 733
 734        /* Test runs until the callback setup() tells the test to stop. */
 735        while (1) {
 736                if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) ||
 737                    !strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) {
 738                        ret = param->setup(1, param);
 739                        if (ret) {
 740                                ret = 0;
 741                                break;
 742                        }
 743
 744                        ret = measure_vals(param, &bw_resc_start);
 745                        if (ret)
 746                                break;
 747                } else if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) {
 748                        ret = param->setup(1, param);
 749                        if (ret) {
 750                                ret = 0;
 751                                break;
 752                        }
 753                        sleep(1);
 754                        ret = measure_cache_vals(param, bm_pid);
 755                        if (ret)
 756                                break;
 757                } else {
 758                        break;
 759                }
 760        }
 761
 762out:
 763        kill(bm_pid, SIGKILL);
 764        umount_resctrlfs();
 765
 766        return ret;
 767}
 768