On Sat, 9 Feb 2019 18:50:33 -0800 Fenghua Yu <[email protected]> wrote:
Hi, > From: Sai Praneeth Prakhya <[email protected]> > > The callback starts a child process and puts the child pid in created > resctrl group with specified memory bandwidth in schemata. The child > starts running benchmark. > > Signed-off-by: Sai Praneeth Prakhya <[email protected]> > Signed-off-by: Arshiya Hayatkhan Pathan <[email protected]> > Signed-off-by: Fenghua Yu <[email protected]> > Signed-off-by: Babu Moger <[email protected]> > --- > tools/testing/selftests/resctrl/resctrl.h | 27 ++ > tools/testing/selftests/resctrl/resctrl_val.c | 582 > ++++++++++++++++++++++++++ > 2 files changed, 609 insertions(+) > > diff --git a/tools/testing/selftests/resctrl/resctrl.h > b/tools/testing/selftests/resctrl/resctrl.h > index 2e112934d48a..c286790ba24d 100644 > --- a/tools/testing/selftests/resctrl/resctrl.h > +++ b/tools/testing/selftests/resctrl/resctrl.h > @@ -3,6 +3,7 @@ > #ifndef RESCTRL_H > #define RESCTRL_H > #include <stdio.h> > +#include <stdarg.h> > #include <errno.h> > #include <sched.h> > #include <stdlib.h> > @@ -28,10 +29,35 @@ > exit(EXIT_FAILURE); \ > } while (0) > > +/* > + * resctrl_val_param: resctrl test parameters > + * @resctrl_val: Resctrl feature (Eg: mbm, mba.. etc) > + * @ctrlgrp: Name of the control monitor group (con_mon grp) > + * @mongrp: Name of the monitor group (mon grp) > + * @cpu_no: CPU number to which the benchmark would be binded > + * @span: Memory bytes accessed in each benchmark iteration > + * @mum_resctrlfs: Should the resctrl FS be remounted? > + * @filename: Name of file to which the o/p should be written > + * @bw_report: Bandwidth report type (reads vs writes) > + * @setup: Call back function to setup test environment > + */ > +struct resctrl_val_param { > + char *resctrl_val; > + char ctrlgrp[64]; > + char mongrp[64]; > + int cpu_no; > + int span; > + int mum_resctrlfs; > + char filename[64]; > + char *bw_report; > + int (*setup)(int num, ...); > +}; > + > pid_t bm_pid, ppid; > > int remount_resctrlfs(bool mum_resctrlfs); > int get_resource_id(int cpu_no, int *resource_id); > +int umount_resctrlfs(void); > int validate_bw_report_request(char *bw_report); > int validate_resctrl_feature_request(char *resctrl_val); > int taskset_benchmark(pid_t bm_pid, int cpu_no); > @@ -44,5 +70,6 @@ int perf_event_open(struct perf_event_attr *hw_event, pid_t > pid, int cpu, > int group_fd, unsigned long flags); > int run_fill_buf(unsigned long span, int malloc_and_init_memory, int > memflush, > int op, char *resctrl_va); > +int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param); > > #endif /* RESCTRL_H */ > diff --git a/tools/testing/selftests/resctrl/resctrl_val.c > b/tools/testing/selftests/resctrl/resctrl_val.c > index 2bb317715a2a..43c15e382892 100644 > --- a/tools/testing/selftests/resctrl/resctrl_val.c > +++ b/tools/testing/selftests/resctrl/resctrl_val.c > @@ -11,6 +11,7 @@ > */ > #include "resctrl.h" > > +#define MB (1024 * 1024) > #define UNCORE_IMC "uncore_imc" > #define READ_FILE_NAME "events/cas_count_read" > #define WRITE_FILE_NAME "events/cas_count_write" > @@ -48,6 +49,8 @@ struct imc_counter_config { > int fd; > }; > > +static char mbm_total_path[1024]; > +static int imcs; > static struct imc_counter_config imc_counters_config[MAX_IMCS][2]; > > void membw_initialize_perf_event_attr(int i, int j) > @@ -116,3 +119,582 @@ void get_event_and_umask(char *cas_count_cfg, int > count, bool op) > } > } > } > + > +static int open_perf_event(int i, int cpu_no, int j) > +{ > + imc_counters_config[i][j].fd = > + perf_event_open(&imc_counters_config[i][j].pe, -1, cpu_no, -1, > + PERF_FLAG_FD_CLOEXEC); > + > + if (imc_counters_config[i][j].fd == -1) { > + fprintf(stderr, "Error opening leader %llx\n", > + imc_counters_config[i][j].pe.config); > + > + return -1; > + } > + > + return 0; > +} > + > +/* Get type and config (read and write) of an iMC counter */ > +static int read_from_imc_dir(char *imc_dir, int count) > +{ > + char cas_count_cfg[1024], imc_counter_cfg[1024], imc_counter_type[1024]; > + FILE *fp; > + > + /* Get type of iMC counter */ > + sprintf(imc_counter_type, "%s%s", imc_dir, "type"); > + fp = fopen(imc_counter_type, "r"); > + if (!fp) { > + perror("Failed to open imc counter type file"); > + > + return -1; > + } > + if (fscanf(fp, "%u", &imc_counters_config[count][READ].type) <= 0) { > + perror("Could not get imc type"); > + fclose(fp); > + > + return -1; > + } > + fclose(fp); > + > + imc_counters_config[count][WRITE].type = > + imc_counters_config[count][READ].type; > + > + /* Get read config */ > + sprintf(imc_counter_cfg, "%s%s", imc_dir, READ_FILE_NAME); > + fp = fopen(imc_counter_cfg, "r"); > + if (!fp) { > + perror("Failed to open imc config file"); > + > + return -1; > + } > + if (fscanf(fp, "%s", cas_count_cfg) <= 0) { > + perror("Could not get imc cas count read"); > + fclose(fp); > + > + return -1; > + } > + fclose(fp); > + > + get_event_and_umask(cas_count_cfg, count, READ); > + > + /* Get write config */ > + sprintf(imc_counter_cfg, "%s%s", imc_dir, WRITE_FILE_NAME); > + fp = fopen(imc_counter_cfg, "r"); > + if (!fp) { > + perror("Failed to open imc config file"); > + > + return -1; > + } > + if (fscanf(fp, "%s", cas_count_cfg) <= 0) { > + perror("Could not get imc cas count write"); > + fclose(fp); > + > + return -1; > + } > + fclose(fp); > + > + get_event_and_umask(cas_count_cfg, count, WRITE); > + > + return 0; > +} > + > +/* > + * A system can have 'n' number of iMC (Integrated Memory Controller) > + * counters, get that 'n'. For each iMC counter get it's type and config. > + * Also, each counter has two configs, one for read and the other for write. > + * A config again has two parts, event and umask. > + * Enumerate all these details into an array of structures. > + * > + * Return: >= 0 on success. < 0 on failure. > + */ > +static int num_of_imcs(void) > +{ > + unsigned int count = 0; > + char imc_dir[1024]; > + struct dirent *ep; > + int ret; > + DIR *dp; > + > + dp = opendir(DYN_PMU_PATH); > + if (dp) { Changing this to: if (!dp) { and handling the error case first makes this more readable and avoids the indentation. > + while ((ep = readdir(dp))) { > + if (strstr(ep->d_name, UNCORE_IMC)) { > + sprintf(imc_dir, "%s/%s/", DYN_PMU_PATH, > + ep->d_name); > + ret = read_from_imc_dir(imc_dir, count); > + if (ret) { > + closedir(dp); > + > + return ret; > + } > + count++; > + } > + } > + closedir(dp); > + if (count == 0) { > + perror("Unable find iMC counters!\n"); > + > + return -1; > + } > + } else { > + perror("Unable to open PMU directory!\n"); > + > + return -1; > + } > + > + return count; > +} > + > +static int initialize_mem_bw_imc(void) > +{ > + int imc, j; > + > + imcs = num_of_imcs(); > + if (imcs <= 0) > + return imcs; > + > + /* Initialize perf_event_attr structures for all iMC's */ > + for (imc = 0; imc < imcs; imc++) { > + for (j = 0; j < 2; j++) > + membw_initialize_perf_event_attr(imc, j); > + } > + > + return 0; > +} > + > +/* > + * get_mem_bw_imc: Memory band width as reported by iMC counters > + * @cpu_no: CPU number that the benchmark PID is binded to > + * @bw_report: Bandwidth report type (reads, writes) > + * > + * Memory B/W utilized by a process on a socket can be calculated using > + * iMC counters. Perf events are used to read these counters. > + * > + * Return: >= 0 on success. < 0 on failure. > + */ > +static float get_mem_bw_imc(int cpu_no, char *bw_report) > +{ > + float reads, writes, of_mul_read, of_mul_write; > + int imc, j, ret; > + > + /* Start all iMC counters to log values (both read and write) */ > + reads = 0, writes = 0, of_mul_read = 1, of_mul_write = 1; > + for (imc = 0; imc < imcs; imc++) { > + for (j = 0; j < 2; j++) { > + ret = open_perf_event(imc, cpu_no, j); > + if (ret) > + return -1; > + } > + for (j = 0; j < 2; j++) > + membw_ioctl_perf_event_ioc_reset_enable(imc, j); > + } > + > + sleep(1); > + > + /* Stop counters after a second to get results (both read and write) */ > + for (imc = 0; imc < imcs; imc++) { > + for (j = 0; j < 2; j++) > + membw_ioctl_perf_event_ioc_disable(imc, j); > + } > + > + /* > + * Get results which are stored in struct type imc_counter_config > + * Take over flow into consideration before calculating total b/w > + */ > + for (imc = 0; imc < imcs; imc++) { > + struct imc_counter_config *r = > + &imc_counters_config[imc][READ]; > + struct imc_counter_config *w = > + &imc_counters_config[imc][WRITE]; > + > + if (read(r->fd, &r->return_value, > + sizeof(struct membw_read_format)) == -1) { > + perror("Couldn't get read b/w through iMC"); > + > + return -1; > + } > + > + if (read(w->fd, &w->return_value, > + sizeof(struct membw_read_format)) == -1) { > + perror("Couldn't get write bw through iMC"); > + > + return -1; > + } > + > + __u64 r_time_enabled = r->return_value.time_enabled; > + __u64 r_time_running = r->return_value.time_running; > + > + if (r_time_enabled != r_time_running) > + of_mul_read = (float)r_time_enabled / > + (float)r_time_running; > + > + __u64 w_time_enabled = w->return_value.time_enabled; > + __u64 w_time_running = w->return_value.time_running; > + > + if (w_time_enabled != w_time_running) > + of_mul_write = (float)w_time_enabled / > + (float)w_time_running; > + reads += r->return_value.value * of_mul_read * SCALE; > + writes += w->return_value.value * of_mul_write * SCALE; > + } > + > + for (imc = 0; imc < imcs; imc++) { > + close(imc_counters_config[imc][READ].fd); > + close(imc_counters_config[imc][WRITE].fd); > + } > + > + if (strcmp(bw_report, "reads") == 0) > + return reads; > + > + if (strcmp(bw_report, "writes") == 0) > + return writes; > + > + return (reads + writes); > +} > + > +void set_mbm_path(const char *ctrlgrp, const char *mongrp, int resource_id) > +{ > + if (ctrlgrp && mongrp) > + sprintf(mbm_total_path, CON_MON_MBM_LOCAL_BYTES_PATH, > + RESCTRL_PATH, ctrlgrp, mongrp, resource_id); > + else if (!ctrlgrp && mongrp) > + sprintf(mbm_total_path, MON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, > + mongrp, resource_id); > + else if (ctrlgrp && !mongrp) > + sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, > + ctrlgrp, resource_id); > + else if (!ctrlgrp && !mongrp) > + sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH, RESCTRL_PATH, > + resource_id); > +} > + > +/* > + * initialize_mem_bw_resctrl: Appropriately populate "mbm_total_path" > + * @ctrlgrp: Name of the control monitor group (con_mon grp) > + * @mongrp: Name of the monitor group (mon grp) > + * @cpu_no: CPU number that the benchmark PID is binded to > + * @resctrl_val: Resctrl feature (Eg: mbm, mba.. etc) > + */ > +static void initialize_mem_bw_resctrl(const char *ctrlgrp, const char > *mongrp, > + int cpu_no, char *resctrl_val) > +{ > + int resource_id; > + > + if (get_resource_id(cpu_no, &resource_id) < 0) { > + perror("Could not get resource_id"); > + return; > + } > + > + if (strcmp(resctrl_val, "mbm") == 0) > + set_mbm_path(ctrlgrp, mongrp, resource_id); > + > + if ((strcmp(resctrl_val, "mba") == 0)) { > + if (ctrlgrp) > + sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, > + RESCTRL_PATH, ctrlgrp, resource_id); > + else > + sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH, > + RESCTRL_PATH, resource_id); > + } > +} > + > +/* > + * Get MBM Local bytes as reported by resctrl FS > + * For MBM, > + * 1. If con_mon grp and mon grp are given, then read from con_mon grp's mon > grp > + * 2. If only con_mon grp is given, then read from con_mon grp > + * 3. If both are not given, then read from root con_mon grp > + * For MBA, > + * 1. If con_mon grp is given, then read from it > + * 2. If con_mon grp is not given, then read from root con_mon grp > + */ > +static unsigned long get_mem_bw_resctrl(void) > +{ > + unsigned long mbm_total = 0; > + FILE *fp; > + > + fp = fopen(mbm_total_path, "r"); > + if (!fp) { > + perror("Failed to open total bw file"); > + > + return -1; > + } > + if (fscanf(fp, "%lu", &mbm_total) <= 0) { > + perror("Could not get mbm local bytes"); > + fclose(fp); > + > + return -1; > + } > + fclose(fp); > + > + return mbm_total; > +} > + > +pid_t bm_pid, ppid; > + > +static void ctrlc_handler(int signum, siginfo_t *info, void *ptr) > +{ > + kill(bm_pid, SIGKILL); > + printf("Ending\n\n"); > + > + exit(EXIT_SUCCESS); > +} > + > +/* > + * print_results_bw: the memory bandwidth results are stored in a file > + * @filename: file that stores the results > + * @bm_pid: child pid that runs benchmark > + * @bw_imc: perf imc counter value > + * @bw_resc: memory bandwidth value > + * > + * Return: 0 on success. non-zero on failure. > + */ > +static int print_results_bw(char *filename, int bm_pid, float bw_imc, > + unsigned long bw_resc) > +{ > + unsigned long diff = labs(bw_imc - bw_resc); Since bw_imc is float (why, actually?) this should be fabs(). clang complains about it. > + FILE *fp; > + > + if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) { > + printf("Pid: %d \t Mem_BW_iMC: %f \t ", bm_pid, bw_imc); > + printf("Mem_BW_resc: %lu \t Difference: %lu\n", bw_resc, diff); > + } else { > + fp = fopen(filename, "a"); > + if (!fp) { > + perror("Cannot open results file"); > + > + return errno; > + } > + if (fprintf(fp, "Pid: %d \t Mem_BW_iMC: %f \t Mem_BW_resc: %lu > \t Difference: %lu\n", > + bm_pid, bw_imc, bw_resc, diff) <= 0) { > + fclose(fp); > + perror("Could not log results."); > + > + return errno; > + } > + fclose(fp); > + } > + > + return 0; > +} > + > +static int > +measure_vals(struct resctrl_val_param *param, unsigned long *bw_resc_start) > +{ > + unsigned long bw_imc, bw_resc, bw_resc_end; > + int ret; > + > + /* > + * Measure memory bandwidth from resctrl and from > + * another source which is perf imc value or could > + * be something else if perf imc event is not available. > + * Compare the two values to validate resctrl value. > + * It takes 1sec to measure the data. > + */ > + bw_imc = get_mem_bw_imc(param->cpu_no, param->bw_report); > + if (bw_imc <= 0) > + return bw_imc; > + > + bw_resc_end = get_mem_bw_resctrl(); > + if (bw_resc_end <= 0) > + return bw_resc_end; > + > + bw_resc = (bw_resc_end - *bw_resc_start) / MB; > + ret = print_results_bw(param->filename, bm_pid, bw_imc, bw_resc); > + if (ret) > + return ret; > + > + *bw_resc_start = bw_resc_end; > + > + return 0; > +} > + > +/* > + * resctrl_val: execute benchmark and measure memory bandwidth on > + * the benchmark > + * @benchmark_cmd: benchmark command and its arguments > + * @param: parameters passed to resctrl_val() > + * > + * Return: 0 on success. non-zero on failure. > + */ > +int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param) > +{ > + int ret = 0, pipefd[2], pipe_message = 0; If I get this correctly, we just need to pipe for asynchronous signalling. So can't we actually use a signal() call here? At least we should make this pipe_message a single char. This avoids some nasty problems with read() and write() possibly returning early. > + char *resctrl_val = param->resctrl_val; > + unsigned long bw_resc_start = 0; > + struct sigaction sigact; > + union sigval value; > + FILE *fp; > + > + if (strcmp(param->filename, "") == 0) > + sprintf(param->filename, "stdio"); > + > + if (strcmp(param->bw_report, "") == 0) > + param->bw_report = "total"; > + > + if ((strcmp(resctrl_val, "mba")) == 0 || > + (strcmp(resctrl_val, "mbm")) == 0) { > + ret = validate_bw_report_request(param->bw_report); > + if (ret) > + return ret; > + } > + > + ret = remount_resctrlfs(param->mum_resctrlfs); > + if (ret) > + return ret; > + > + /* > + * If benchmark wasn't successfully started by child, then child should > + * kill parent, so save parent's pid > + */ > + ppid = getpid(); > + > + /* File based synchronization between parent and child */ > + fp = fopen("sig", "w"); > + if (!fp) { > + perror("Failed to open sig file"); > + > + return -1; > + } > + if (fprintf(fp, "%d\n", 0) <= 0) { > + perror("Unable to establish sync bw parent & child"); > + fclose(fp); > + > + return -1; > + } > + fclose(fp); > + > + if (pipe(pipefd)) { > + perror("Unable to create pipe"); > + > + return -1; > + } > + > + /* > + * Fork to start benchmark, save child's pid so that it can be killed > + * when needed > + */ > + bm_pid = fork(); > + if (bm_pid == -1) { > + perror("Unable to fork"); > + > + return -1; > + } > + > + if (bm_pid == 0) { > + /* > + * Mask all signals except SIGUSR1, parent uses SIGUSR1 to > + * start benchmark > + */ > + sigfillset(&sigact.sa_mask); > + sigdelset(&sigact.sa_mask, SIGUSR1); > + > + sigact.sa_sigaction = run_benchmark; > + sigact.sa_flags = SA_SIGINFO; > + > + /* Register for "SIGUSR1" signal from parent */ > + if (sigaction(SIGUSR1, &sigact, NULL)) > + PARENT_EXIT("Can't register child for signal"); > + > + /* Tell parent that child is ready */ > + close(pipefd[0]); > + pipe_message = 1; > + write(pipefd[1], &pipe_message, sizeof(pipe_message)); gcc -O complains about an unchecked return value of write() here. We could just compare against sizeof(pipe_message) and bail out if it's smaller. > + close(pipefd[1]); > + > + /* Suspend child until delivery of "SIGUSR1" from parent */ > + sigsuspend(&sigact.sa_mask); > + > + PARENT_EXIT("Child is done"); > + } > + > + printf("Benchmark PID: %d\n", bm_pid); > + > + /* > + * Register CTRL-C handler for parent, as it has to kill benchmark > + * before exiting > + */ > + sigact.sa_sigaction = ctrlc_handler; > + sigemptyset(&sigact.sa_mask); > + sigact.sa_flags = SA_SIGINFO; > + if (sigaction(SIGINT, &sigact, NULL) || > + sigaction(SIGHUP, &sigact, NULL)) { > + perror("Can't register parent for CTRL-C handler"); > + ret = errno; > + goto out; > + } > + > + value.sival_ptr = benchmark_cmd; > + > + /* Taskset benchmark to specified cpu */ > + ret = taskset_benchmark(bm_pid, param->cpu_no); > + if (ret) > + goto out; > + > + /* Write benchmark to specified control&monitoring grp in resctrl FS */ > + ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp, > + resctrl_val); > + if (ret) > + goto out; > + > + if ((strcmp(resctrl_val, "mbm") == 0) || > + (strcmp(resctrl_val, "mba") == 0)) { > + ret = initialize_mem_bw_imc(); > + if (ret) > + goto out; > + > + initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp, > + param->cpu_no, resctrl_val); > + } > + > + /* Parent waits for child to be ready. */ > + close(pipefd[1]); > + while (pipe_message != 1) > + read(pipefd[0], &pipe_message, sizeof(pipe_message)); Same thing with checking the return value here. Cheers, Andre. > + close(pipefd[0]); > + > + /* Signal child to start benchmark */ > + if (sigqueue(bm_pid, SIGUSR1, value) == -1) { > + perror("Unable to signal child to start execution"); > + ret = errno; > + goto out; > + } > + > + /* Give benchmark enough time to fully run */ > + sleep(1); > + > + /* Test runs until the callback setup() tells the test to stop. */ > + while (1) { > + if (strcmp(resctrl_val, "mbm") == 0) { > + ret = param->setup(1, param); > + if (ret) { > + ret = 0; > + break; > + } > + > + ret = measure_vals(param, &bw_resc_start); > + if (ret) > + break; > + } else if ((strcmp(resctrl_val, "mba") == 0)) { > + ret = param->setup(1, param); > + if (ret) { > + ret = 0; > + break; > + } > + > + ret = measure_vals(param, &bw_resc_start); > + if (ret) > + break; > + } else { > + break; > + } > + } > + > +out: > + kill(bm_pid, SIGKILL); > + umount_resctrlfs(); > + > + return ret; > +}
