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1// SPDX-License-Identifier: GPL-2.02/*3 * Memory bandwidth monitoring and allocation library4 *5 * Copyright (C) 2018 Intel Corporation6 *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 0.0000610351562518#define MAX_IMCS 2019#define MAX_TOKENS 520#define READ 021#define WRITE 122 23#define CON_MBM_LOCAL_BYTES_PATH \24 "%s/%s/mon_data/mon_L3_%02d/mbm_local_bytes"25 26struct membw_read_format {27 __u64 value; /* The value of the event */28 __u64 time_enabled; /* if PERF_FORMAT_TOTAL_TIME_ENABLED */29 __u64 time_running; /* if PERF_FORMAT_TOTAL_TIME_RUNNING */30 __u64 id; /* if PERF_FORMAT_ID */31};32 33struct imc_counter_config {34 __u32 type;35 __u64 event;36 __u64 umask;37 struct perf_event_attr pe;38 struct membw_read_format return_value;39 int fd;40};41 42static char mbm_total_path[1024];43static int imcs;44static struct imc_counter_config imc_counters_config[MAX_IMCS][2];45static const struct resctrl_test *current_test;46 47void membw_initialize_perf_event_attr(int i, int j)48{49 memset(&imc_counters_config[i][j].pe, 0,50 sizeof(struct perf_event_attr));51 imc_counters_config[i][j].pe.type = imc_counters_config[i][j].type;52 imc_counters_config[i][j].pe.size = sizeof(struct perf_event_attr);53 imc_counters_config[i][j].pe.disabled = 1;54 imc_counters_config[i][j].pe.inherit = 1;55 imc_counters_config[i][j].pe.exclude_guest = 0;56 imc_counters_config[i][j].pe.config =57 imc_counters_config[i][j].umask << 8 |58 imc_counters_config[i][j].event;59 imc_counters_config[i][j].pe.sample_type = PERF_SAMPLE_IDENTIFIER;60 imc_counters_config[i][j].pe.read_format =61 PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING;62}63 64void membw_ioctl_perf_event_ioc_reset_enable(int i, int j)65{66 ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_RESET, 0);67 ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_ENABLE, 0);68}69 70void membw_ioctl_perf_event_ioc_disable(int i, int j)71{72 ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_DISABLE, 0);73}74 75/*76 * get_event_and_umask: Parse config into event and umask77 * @cas_count_cfg: Config78 * @count: iMC number79 * @op: Operation (read/write)80 */81void get_event_and_umask(char *cas_count_cfg, int count, bool op)82{83 char *token[MAX_TOKENS];84 int i = 0;85 86 strcat(cas_count_cfg, ",");87 token[0] = strtok(cas_count_cfg, "=,");88 89 for (i = 1; i < MAX_TOKENS; i++)90 token[i] = strtok(NULL, "=,");91 92 for (i = 0; i < MAX_TOKENS; i++) {93 if (!token[i])94 break;95 if (strcmp(token[i], "event") == 0) {96 if (op == READ)97 imc_counters_config[count][READ].event =98 strtol(token[i + 1], NULL, 16);99 else100 imc_counters_config[count][WRITE].event =101 strtol(token[i + 1], NULL, 16);102 }103 if (strcmp(token[i], "umask") == 0) {104 if (op == READ)105 imc_counters_config[count][READ].umask =106 strtol(token[i + 1], NULL, 16);107 else108 imc_counters_config[count][WRITE].umask =109 strtol(token[i + 1], NULL, 16);110 }111 }112}113 114static int open_perf_event(int i, int cpu_no, int j)115{116 imc_counters_config[i][j].fd =117 perf_event_open(&imc_counters_config[i][j].pe, -1, cpu_no, -1,118 PERF_FLAG_FD_CLOEXEC);119 120 if (imc_counters_config[i][j].fd == -1) {121 fprintf(stderr, "Error opening leader %llx\n",122 imc_counters_config[i][j].pe.config);123 124 return -1;125 }126 127 return 0;128}129 130/* Get type and config (read and write) of an iMC counter */131static int read_from_imc_dir(char *imc_dir, int count)132{133 char cas_count_cfg[1024], imc_counter_cfg[1024], imc_counter_type[1024];134 FILE *fp;135 136 /* Get type of iMC counter */137 sprintf(imc_counter_type, "%s%s", imc_dir, "type");138 fp = fopen(imc_counter_type, "r");139 if (!fp) {140 ksft_perror("Failed to open iMC counter type file");141 142 return -1;143 }144 if (fscanf(fp, "%u", &imc_counters_config[count][READ].type) <= 0) {145 ksft_perror("Could not get iMC type");146 fclose(fp);147 148 return -1;149 }150 fclose(fp);151 152 imc_counters_config[count][WRITE].type =153 imc_counters_config[count][READ].type;154 155 /* Get read config */156 sprintf(imc_counter_cfg, "%s%s", imc_dir, READ_FILE_NAME);157 fp = fopen(imc_counter_cfg, "r");158 if (!fp) {159 ksft_perror("Failed to open iMC config file");160 161 return -1;162 }163 if (fscanf(fp, "%s", cas_count_cfg) <= 0) {164 ksft_perror("Could not get iMC cas count read");165 fclose(fp);166 167 return -1;168 }169 fclose(fp);170 171 get_event_and_umask(cas_count_cfg, count, READ);172 173 /* Get write config */174 sprintf(imc_counter_cfg, "%s%s", imc_dir, WRITE_FILE_NAME);175 fp = fopen(imc_counter_cfg, "r");176 if (!fp) {177 ksft_perror("Failed to open iMC config file");178 179 return -1;180 }181 if (fscanf(fp, "%s", cas_count_cfg) <= 0) {182 ksft_perror("Could not get iMC cas count write");183 fclose(fp);184 185 return -1;186 }187 fclose(fp);188 189 get_event_and_umask(cas_count_cfg, count, WRITE);190 191 return 0;192}193 194/*195 * A system can have 'n' number of iMC (Integrated Memory Controller)196 * counters, get that 'n'. For each iMC counter get it's type and config.197 * Also, each counter has two configs, one for read and the other for write.198 * A config again has two parts, event and umask.199 * Enumerate all these details into an array of structures.200 *201 * Return: >= 0 on success. < 0 on failure.202 */203static int num_of_imcs(void)204{205 char imc_dir[512], *temp;206 unsigned int count = 0;207 struct dirent *ep;208 int ret;209 DIR *dp;210 211 dp = opendir(DYN_PMU_PATH);212 if (dp) {213 while ((ep = readdir(dp))) {214 temp = strstr(ep->d_name, UNCORE_IMC);215 if (!temp)216 continue;217 218 /*219 * imc counters are named as "uncore_imc_<n>", hence220 * increment the pointer to point to <n>. Note that221 * sizeof(UNCORE_IMC) would count for null character as222 * well and hence the last underscore character in223 * uncore_imc'_' need not be counted.224 */225 temp = temp + sizeof(UNCORE_IMC);226 227 /*228 * Some directories under "DYN_PMU_PATH" could have229 * names like "uncore_imc_free_running", hence, check if230 * first character is a numerical digit or not.231 */232 if (temp[0] >= '0' && temp[0] <= '9') {233 sprintf(imc_dir, "%s/%s/", DYN_PMU_PATH,234 ep->d_name);235 ret = read_from_imc_dir(imc_dir, count);236 if (ret) {237 closedir(dp);238 239 return ret;240 }241 count++;242 }243 }244 closedir(dp);245 if (count == 0) {246 ksft_print_msg("Unable to find iMC counters\n");247 248 return -1;249 }250 } else {251 ksft_perror("Unable to open PMU directory");252 253 return -1;254 }255 256 return count;257}258 259int initialize_mem_bw_imc(void)260{261 int imc, j;262 263 imcs = num_of_imcs();264 if (imcs <= 0)265 return imcs;266 267 /* Initialize perf_event_attr structures for all iMC's */268 for (imc = 0; imc < imcs; imc++) {269 for (j = 0; j < 2; j++)270 membw_initialize_perf_event_attr(imc, j);271 }272 273 return 0;274}275 276static void perf_close_imc_mem_bw(void)277{278 int mc;279 280 for (mc = 0; mc < imcs; mc++) {281 if (imc_counters_config[mc][READ].fd != -1)282 close(imc_counters_config[mc][READ].fd);283 if (imc_counters_config[mc][WRITE].fd != -1)284 close(imc_counters_config[mc][WRITE].fd);285 }286}287 288/*289 * perf_open_imc_mem_bw - Open perf fds for IMCs290 * @cpu_no: CPU number that the benchmark PID is bound to291 *292 * Return: = 0 on success. < 0 on failure.293 */294static int perf_open_imc_mem_bw(int cpu_no)295{296 int imc, ret;297 298 for (imc = 0; imc < imcs; imc++) {299 imc_counters_config[imc][READ].fd = -1;300 imc_counters_config[imc][WRITE].fd = -1;301 }302 303 for (imc = 0; imc < imcs; imc++) {304 ret = open_perf_event(imc, cpu_no, READ);305 if (ret)306 goto close_fds;307 ret = open_perf_event(imc, cpu_no, WRITE);308 if (ret)309 goto close_fds;310 }311 312 return 0;313 314close_fds:315 perf_close_imc_mem_bw();316 return -1;317}318 319/*320 * do_mem_bw_test - Perform memory bandwidth test321 *322 * Runs memory bandwidth test over one second period. Also, handles starting323 * and stopping of the IMC perf counters around the test.324 */325static void do_imc_mem_bw_test(void)326{327 int imc;328 329 for (imc = 0; imc < imcs; imc++) {330 membw_ioctl_perf_event_ioc_reset_enable(imc, READ);331 membw_ioctl_perf_event_ioc_reset_enable(imc, WRITE);332 }333 334 sleep(1);335 336 /* Stop counters after a second to get results (both read and write) */337 for (imc = 0; imc < imcs; imc++) {338 membw_ioctl_perf_event_ioc_disable(imc, READ);339 membw_ioctl_perf_event_ioc_disable(imc, WRITE);340 }341}342 343/*344 * get_mem_bw_imc - Memory bandwidth as reported by iMC counters345 * @bw_report: Bandwidth report type (reads, writes)346 *347 * Memory bandwidth utilized by a process on a socket can be calculated348 * using iMC counters. Perf events are used to read these counters.349 *350 * Return: = 0 on success. < 0 on failure.351 */352static int get_mem_bw_imc(const char *bw_report, float *bw_imc)353{354 float reads, writes, of_mul_read, of_mul_write;355 int imc;356 357 /* Start all iMC counters to log values (both read and write) */358 reads = 0, writes = 0, of_mul_read = 1, of_mul_write = 1;359 360 /*361 * Get results which are stored in struct type imc_counter_config362 * Take overflow into consideration before calculating total bandwidth.363 */364 for (imc = 0; imc < imcs; imc++) {365 struct imc_counter_config *r =366 &imc_counters_config[imc][READ];367 struct imc_counter_config *w =368 &imc_counters_config[imc][WRITE];369 370 if (read(r->fd, &r->return_value,371 sizeof(struct membw_read_format)) == -1) {372 ksft_perror("Couldn't get read bandwidth through iMC");373 return -1;374 }375 376 if (read(w->fd, &w->return_value,377 sizeof(struct membw_read_format)) == -1) {378 ksft_perror("Couldn't get write bandwidth through iMC");379 return -1;380 }381 382 __u64 r_time_enabled = r->return_value.time_enabled;383 __u64 r_time_running = r->return_value.time_running;384 385 if (r_time_enabled != r_time_running)386 of_mul_read = (float)r_time_enabled /387 (float)r_time_running;388 389 __u64 w_time_enabled = w->return_value.time_enabled;390 __u64 w_time_running = w->return_value.time_running;391 392 if (w_time_enabled != w_time_running)393 of_mul_write = (float)w_time_enabled /394 (float)w_time_running;395 reads += r->return_value.value * of_mul_read * SCALE;396 writes += w->return_value.value * of_mul_write * SCALE;397 }398 399 if (strcmp(bw_report, "reads") == 0) {400 *bw_imc = reads;401 return 0;402 }403 404 if (strcmp(bw_report, "writes") == 0) {405 *bw_imc = writes;406 return 0;407 }408 409 *bw_imc = reads + writes;410 return 0;411}412 413/*414 * initialize_mem_bw_resctrl: Appropriately populate "mbm_total_path"415 * @param: Parameters passed to resctrl_val()416 * @domain_id: Domain ID (cache ID; for MB, L3 cache ID)417 */418void initialize_mem_bw_resctrl(const struct resctrl_val_param *param,419 int domain_id)420{421 sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH,422 param->ctrlgrp, domain_id);423}424 425/*426 * Open file to read MBM local bytes from resctrl FS427 */428static FILE *open_mem_bw_resctrl(const char *mbm_bw_file)429{430 FILE *fp;431 432 fp = fopen(mbm_bw_file, "r");433 if (!fp)434 ksft_perror("Failed to open total memory bandwidth file");435 436 return fp;437}438 439/*440 * Get MBM Local bytes as reported by resctrl FS441 */442static int get_mem_bw_resctrl(FILE *fp, unsigned long *mbm_total)443{444 if (fscanf(fp, "%lu\n", mbm_total) <= 0) {445 ksft_perror("Could not get MBM local bytes");446 return -1;447 }448 return 0;449}450 451static pid_t bm_pid, ppid;452 453void ctrlc_handler(int signum, siginfo_t *info, void *ptr)454{455 /* Only kill child after bm_pid is set after fork() */456 if (bm_pid)457 kill(bm_pid, SIGKILL);458 umount_resctrlfs();459 if (current_test && current_test->cleanup)460 current_test->cleanup();461 ksft_print_msg("Ending\n\n");462 463 exit(EXIT_SUCCESS);464}465 466/*467 * Register CTRL-C handler for parent, as it has to kill468 * child process before exiting.469 */470int signal_handler_register(const struct resctrl_test *test)471{472 struct sigaction sigact = {};473 int ret = 0;474 475 bm_pid = 0;476 477 current_test = test;478 sigact.sa_sigaction = ctrlc_handler;479 sigemptyset(&sigact.sa_mask);480 sigact.sa_flags = SA_SIGINFO;481 if (sigaction(SIGINT, &sigact, NULL) ||482 sigaction(SIGTERM, &sigact, NULL) ||483 sigaction(SIGHUP, &sigact, NULL)) {484 ksft_perror("sigaction");485 ret = -1;486 }487 return ret;488}489 490/*491 * Reset signal handler to SIG_DFL.492 * Non-Value return because the caller should keep493 * the error code of other path even if sigaction fails.494 */495void signal_handler_unregister(void)496{497 struct sigaction sigact = {};498 499 current_test = NULL;500 sigact.sa_handler = SIG_DFL;501 sigemptyset(&sigact.sa_mask);502 if (sigaction(SIGINT, &sigact, NULL) ||503 sigaction(SIGTERM, &sigact, NULL) ||504 sigaction(SIGHUP, &sigact, NULL)) {505 ksft_perror("sigaction");506 }507}508 509static void parent_exit(pid_t ppid)510{511 kill(ppid, SIGKILL);512 umount_resctrlfs();513 exit(EXIT_FAILURE);514}515 516/*517 * print_results_bw: the memory bandwidth results are stored in a file518 * @filename: file that stores the results519 * @bm_pid: child pid that runs benchmark520 * @bw_imc: perf imc counter value521 * @bw_resc: memory bandwidth value522 *523 * Return: 0 on success, < 0 on error.524 */525static int print_results_bw(char *filename, pid_t bm_pid, float bw_imc,526 unsigned long bw_resc)527{528 unsigned long diff = fabs(bw_imc - bw_resc);529 FILE *fp;530 531 if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {532 printf("Pid: %d \t Mem_BW_iMC: %f \t ", (int)bm_pid, bw_imc);533 printf("Mem_BW_resc: %lu \t Difference: %lu\n", bw_resc, diff);534 } else {535 fp = fopen(filename, "a");536 if (!fp) {537 ksft_perror("Cannot open results file");538 539 return -1;540 }541 if (fprintf(fp, "Pid: %d \t Mem_BW_iMC: %f \t Mem_BW_resc: %lu \t Difference: %lu\n",542 (int)bm_pid, bw_imc, bw_resc, diff) <= 0) {543 ksft_print_msg("Could not log results\n");544 fclose(fp);545 546 return -1;547 }548 fclose(fp);549 }550 551 return 0;552}553 554/*555 * measure_mem_bw - Measures memory bandwidth numbers while benchmark runs556 * @uparams: User supplied parameters557 * @param: Parameters passed to resctrl_val()558 * @bm_pid: PID that runs the benchmark559 * @bw_report: Bandwidth report type (reads, writes)560 *561 * Measure memory bandwidth from resctrl and from another source which is562 * perf imc value or could be something else if perf imc event is not563 * available. Compare the two values to validate resctrl value. It takes564 * 1 sec to measure the data.565 */566int measure_mem_bw(const struct user_params *uparams,567 struct resctrl_val_param *param, pid_t bm_pid,568 const char *bw_report)569{570 unsigned long bw_resc, bw_resc_start, bw_resc_end;571 FILE *mem_bw_fp;572 float bw_imc;573 int ret;574 575 bw_report = get_bw_report_type(bw_report);576 if (!bw_report)577 return -1;578 579 mem_bw_fp = open_mem_bw_resctrl(mbm_total_path);580 if (!mem_bw_fp)581 return -1;582 583 ret = perf_open_imc_mem_bw(uparams->cpu);584 if (ret < 0)585 goto close_fp;586 587 ret = get_mem_bw_resctrl(mem_bw_fp, &bw_resc_start);588 if (ret < 0)589 goto close_imc;590 591 rewind(mem_bw_fp);592 593 do_imc_mem_bw_test();594 595 ret = get_mem_bw_resctrl(mem_bw_fp, &bw_resc_end);596 if (ret < 0)597 goto close_imc;598 599 ret = get_mem_bw_imc(bw_report, &bw_imc);600 if (ret < 0)601 goto close_imc;602 603 perf_close_imc_mem_bw();604 fclose(mem_bw_fp);605 606 bw_resc = (bw_resc_end - bw_resc_start) / MB;607 608 return print_results_bw(param->filename, bm_pid, bw_imc, bw_resc);609 610close_imc:611 perf_close_imc_mem_bw();612close_fp:613 fclose(mem_bw_fp);614 return ret;615}616 617/*618 * run_benchmark - Run a specified benchmark or fill_buf (default benchmark)619 * in specified signal. Direct benchmark stdio to /dev/null.620 * @signum: signal number621 * @info: signal info622 * @ucontext: user context in signal handling623 */624static void run_benchmark(int signum, siginfo_t *info, void *ucontext)625{626 int operation, ret, memflush;627 char **benchmark_cmd;628 size_t span;629 bool once;630 FILE *fp;631 632 benchmark_cmd = info->si_ptr;633 634 /*635 * Direct stdio of child to /dev/null, so that only parent writes to636 * stdio (console)637 */638 fp = freopen("/dev/null", "w", stdout);639 if (!fp) {640 ksft_perror("Unable to direct benchmark status to /dev/null");641 parent_exit(ppid);642 }643 644 if (strcmp(benchmark_cmd[0], "fill_buf") == 0) {645 /* Execute default fill_buf benchmark */646 span = strtoul(benchmark_cmd[1], NULL, 10);647 memflush = atoi(benchmark_cmd[2]);648 operation = atoi(benchmark_cmd[3]);649 if (!strcmp(benchmark_cmd[4], "true")) {650 once = true;651 } else if (!strcmp(benchmark_cmd[4], "false")) {652 once = false;653 } else {654 ksft_print_msg("Invalid once parameter\n");655 parent_exit(ppid);656 }657 658 if (run_fill_buf(span, memflush, operation, once))659 fprintf(stderr, "Error in running fill buffer\n");660 } else {661 /* Execute specified benchmark */662 ret = execvp(benchmark_cmd[0], benchmark_cmd);663 if (ret)664 ksft_perror("execvp");665 }666 667 fclose(stdout);668 ksft_print_msg("Unable to run specified benchmark\n");669 parent_exit(ppid);670}671 672/*673 * resctrl_val: execute benchmark and measure memory bandwidth on674 * the benchmark675 * @test: test information structure676 * @uparams: user supplied parameters677 * @benchmark_cmd: benchmark command and its arguments678 * @param: parameters passed to resctrl_val()679 *680 * Return: 0 when the test was run, < 0 on error.681 */682int resctrl_val(const struct resctrl_test *test,683 const struct user_params *uparams,684 const char * const *benchmark_cmd,685 struct resctrl_val_param *param)686{687 struct sigaction sigact;688 int ret = 0, pipefd[2];689 char pipe_message = 0;690 union sigval value;691 int domain_id;692 693 if (strcmp(param->filename, "") == 0)694 sprintf(param->filename, "stdio");695 696 ret = get_domain_id(test->resource, uparams->cpu, &domain_id);697 if (ret < 0) {698 ksft_print_msg("Could not get domain ID\n");699 return ret;700 }701 702 /*703 * If benchmark wasn't successfully started by child, then child should704 * kill parent, so save parent's pid705 */706 ppid = getpid();707 708 if (pipe(pipefd)) {709 ksft_perror("Unable to create pipe");710 711 return -1;712 }713 714 /*715 * Fork to start benchmark, save child's pid so that it can be killed716 * when needed717 */718 fflush(stdout);719 bm_pid = fork();720 if (bm_pid == -1) {721 ksft_perror("Unable to fork");722 723 return -1;724 }725 726 if (bm_pid == 0) {727 /*728 * Mask all signals except SIGUSR1, parent uses SIGUSR1 to729 * start benchmark730 */731 sigfillset(&sigact.sa_mask);732 sigdelset(&sigact.sa_mask, SIGUSR1);733 734 sigact.sa_sigaction = run_benchmark;735 sigact.sa_flags = SA_SIGINFO;736 737 /* Register for "SIGUSR1" signal from parent */738 if (sigaction(SIGUSR1, &sigact, NULL)) {739 ksft_perror("Can't register child for signal");740 parent_exit(ppid);741 }742 743 /* Tell parent that child is ready */744 close(pipefd[0]);745 pipe_message = 1;746 if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <747 sizeof(pipe_message)) {748 ksft_perror("Failed signaling parent process");749 close(pipefd[1]);750 return -1;751 }752 close(pipefd[1]);753 754 /* Suspend child until delivery of "SIGUSR1" from parent */755 sigsuspend(&sigact.sa_mask);756 757 ksft_perror("Child is done");758 parent_exit(ppid);759 }760 761 ksft_print_msg("Benchmark PID: %d\n", (int)bm_pid);762 763 /*764 * The cast removes constness but nothing mutates benchmark_cmd within765 * the context of this process. At the receiving process, it becomes766 * argv, which is mutable, on exec() but that's after fork() so it767 * doesn't matter for the process running the tests.768 */769 value.sival_ptr = (void *)benchmark_cmd;770 771 /* Taskset benchmark to specified cpu */772 ret = taskset_benchmark(bm_pid, uparams->cpu, NULL);773 if (ret)774 goto out;775 776 /* Write benchmark to specified control&monitoring grp in resctrl FS */777 ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp);778 if (ret)779 goto out;780 781 if (param->init) {782 ret = param->init(param, domain_id);783 if (ret)784 goto out;785 }786 787 /* Parent waits for child to be ready. */788 close(pipefd[1]);789 while (pipe_message != 1) {790 if (read(pipefd[0], &pipe_message, sizeof(pipe_message)) <791 sizeof(pipe_message)) {792 ksft_perror("Failed reading message from child process");793 close(pipefd[0]);794 goto out;795 }796 }797 close(pipefd[0]);798 799 /* Signal child to start benchmark */800 if (sigqueue(bm_pid, SIGUSR1, value) == -1) {801 ksft_perror("sigqueue SIGUSR1 to child");802 ret = -1;803 goto out;804 }805 806 /* Give benchmark enough time to fully run */807 sleep(1);808 809 /* Test runs until the callback setup() tells the test to stop. */810 while (1) {811 ret = param->setup(test, uparams, param);812 if (ret == END_OF_TESTS) {813 ret = 0;814 break;815 }816 if (ret < 0)817 break;818 819 ret = param->measure(uparams, param, bm_pid);820 if (ret)821 break;822 }823 824out:825 kill(bm_pid, SIGKILL);826 827 return ret;828}829