| #include <math.h> |
| #include "json.h" |
| #include "idletime.h" |
| |
| static volatile struct idle_prof_common ipc; |
| |
| /* |
| * Get time to complete an unit work on a particular cpu. |
| * The minimum number in CALIBRATE_RUNS runs is returned. |
| */ |
| static double calibrate_unit(unsigned char *data) |
| { |
| unsigned long t, i, j, k; |
| struct timeval tps; |
| double tunit = 0.0; |
| |
| for (i = 0; i < CALIBRATE_RUNS; i++) { |
| |
| fio_gettime(&tps, NULL); |
| /* scale for less variance */ |
| for (j = 0; j < CALIBRATE_SCALE; j++) { |
| /* unit of work */ |
| for (k=0; k < page_size; k++) { |
| data[(k + j) % page_size] = k % 256; |
| /* |
| * we won't see STOP here. this is to match |
| * the same statement in the profiling loop. |
| */ |
| if (ipc.status == IDLE_PROF_STATUS_PROF_STOP) |
| return 0.0; |
| } |
| } |
| |
| t = utime_since_now(&tps); |
| if (!t) |
| continue; |
| |
| /* get the minimum time to complete CALIBRATE_SCALE units */ |
| if ((i == 0) || ((double)t < tunit)) |
| tunit = (double)t; |
| } |
| |
| return tunit / CALIBRATE_SCALE; |
| } |
| |
| static int set_cpu_affinity(struct idle_prof_thread *ipt) |
| { |
| #if defined(FIO_HAVE_CPU_AFFINITY) |
| os_cpu_mask_t cpu_mask; |
| |
| memset(&cpu_mask, 0, sizeof(cpu_mask)); |
| fio_cpu_set(&cpu_mask, ipt->cpu); |
| |
| if (fio_setaffinity(gettid(), cpu_mask)) { |
| log_err("fio: fio_setaffinity failed\n"); |
| return -1; |
| } |
| |
| return 0; |
| #else |
| log_err("fio: fio_setaffinity not supported\n"); |
| return -1; |
| #endif |
| } |
| |
| static void *idle_prof_thread_fn(void *data) |
| { |
| int retval; |
| unsigned long j, k; |
| struct idle_prof_thread *ipt = data; |
| |
| /* wait for all threads are spawned */ |
| pthread_mutex_lock(&ipt->init_lock); |
| |
| /* exit if any other thread failed to start */ |
| if (ipc.status == IDLE_PROF_STATUS_ABORT) |
| return NULL; |
| |
| retval = set_cpu_affinity(ipt); |
| if (retval == -1) { |
| ipt->state = TD_EXITED; |
| pthread_mutex_unlock(&ipt->init_lock); |
| return NULL; |
| } |
| |
| ipt->cali_time = calibrate_unit(ipt->data); |
| |
| /* delay to set IDLE class till now for better calibration accuracy */ |
| #if defined(CONFIG_SCHED_IDLE) |
| if ((retval = fio_set_sched_idle())) |
| log_err("fio: fio_set_sched_idle failed\n"); |
| #else |
| retval = -1; |
| log_err("fio: fio_set_sched_idle not supported\n"); |
| #endif |
| if (retval == -1) { |
| ipt->state = TD_EXITED; |
| pthread_mutex_unlock(&ipt->init_lock); |
| return NULL; |
| } |
| |
| ipt->state = TD_INITIALIZED; |
| |
| /* signal the main thread that calibration is done */ |
| pthread_cond_signal(&ipt->cond); |
| pthread_mutex_unlock(&ipt->init_lock); |
| |
| /* wait for other calibration to finish */ |
| pthread_mutex_lock(&ipt->start_lock); |
| |
| /* exit if other threads failed to initialize */ |
| if (ipc.status == IDLE_PROF_STATUS_ABORT) |
| return NULL; |
| |
| /* exit if we are doing calibration only */ |
| if (ipc.status == IDLE_PROF_STATUS_CALI_STOP) |
| return NULL; |
| |
| fio_gettime(&ipt->tps, NULL); |
| ipt->state = TD_RUNNING; |
| |
| j = 0; |
| while (1) { |
| for (k = 0; k < page_size; k++) { |
| ipt->data[(k + j) % page_size] = k % 256; |
| if (ipc.status == IDLE_PROF_STATUS_PROF_STOP) { |
| fio_gettime(&ipt->tpe, NULL); |
| goto idle_prof_done; |
| } |
| } |
| j++; |
| } |
| |
| idle_prof_done: |
| |
| ipt->loops = j + (double) k / page_size; |
| ipt->state = TD_EXITED; |
| pthread_mutex_unlock(&ipt->start_lock); |
| |
| return NULL; |
| } |
| |
| /* calculate mean and standard deviation to complete an unit of work */ |
| static void calibration_stats(void) |
| { |
| int i; |
| double sum = 0.0, var = 0.0; |
| struct idle_prof_thread *ipt; |
| |
| for (i = 0; i < ipc.nr_cpus; i++) { |
| ipt = &ipc.ipts[i]; |
| sum += ipt->cali_time; |
| } |
| |
| ipc.cali_mean = sum/ipc.nr_cpus; |
| |
| for (i = 0; i < ipc.nr_cpus; i++) { |
| ipt = &ipc.ipts[i]; |
| var += pow(ipt->cali_time-ipc.cali_mean, 2); |
| } |
| |
| ipc.cali_stddev = sqrt(var/(ipc.nr_cpus-1)); |
| } |
| |
| void fio_idle_prof_init(void) |
| { |
| int i, ret; |
| struct timeval tp; |
| struct timespec ts; |
| pthread_attr_t tattr; |
| struct idle_prof_thread *ipt; |
| |
| ipc.nr_cpus = cpus_online(); |
| ipc.status = IDLE_PROF_STATUS_OK; |
| |
| if (ipc.opt == IDLE_PROF_OPT_NONE) |
| return; |
| |
| if ((ret = pthread_attr_init(&tattr))) { |
| log_err("fio: pthread_attr_init %s\n", strerror(ret)); |
| return; |
| } |
| if ((ret = pthread_attr_setscope(&tattr, PTHREAD_SCOPE_SYSTEM))) { |
| log_err("fio: pthread_attr_setscope %s\n", strerror(ret)); |
| return; |
| } |
| |
| ipc.ipts = malloc(ipc.nr_cpus * sizeof(struct idle_prof_thread)); |
| if (!ipc.ipts) { |
| log_err("fio: malloc failed\n"); |
| return; |
| } |
| |
| ipc.buf = malloc(ipc.nr_cpus * page_size); |
| if (!ipc.buf) { |
| log_err("fio: malloc failed\n"); |
| free(ipc.ipts); |
| return; |
| } |
| |
| /* |
| * profiling aborts on any single thread failure since the |
| * result won't be accurate if any cpu is not used. |
| */ |
| for (i = 0; i < ipc.nr_cpus; i++) { |
| ipt = &ipc.ipts[i]; |
| |
| ipt->cpu = i; |
| ipt->state = TD_NOT_CREATED; |
| ipt->data = (unsigned char *)(ipc.buf + page_size * i); |
| |
| if ((ret = pthread_mutex_init(&ipt->init_lock, NULL))) { |
| ipc.status = IDLE_PROF_STATUS_ABORT; |
| log_err("fio: pthread_mutex_init %s\n", strerror(ret)); |
| break; |
| } |
| |
| if ((ret = pthread_mutex_init(&ipt->start_lock, NULL))) { |
| ipc.status = IDLE_PROF_STATUS_ABORT; |
| log_err("fio: pthread_mutex_init %s\n", strerror(ret)); |
| break; |
| } |
| |
| if ((ret = pthread_cond_init(&ipt->cond, NULL))) { |
| ipc.status = IDLE_PROF_STATUS_ABORT; |
| log_err("fio: pthread_cond_init %s\n", strerror(ret)); |
| break; |
| } |
| |
| /* make sure all threads are spawned before they start */ |
| pthread_mutex_lock(&ipt->init_lock); |
| |
| /* make sure all threads finish init before profiling starts */ |
| pthread_mutex_lock(&ipt->start_lock); |
| |
| if ((ret = pthread_create(&ipt->thread, &tattr, idle_prof_thread_fn, ipt))) { |
| ipc.status = IDLE_PROF_STATUS_ABORT; |
| log_err("fio: pthread_create %s\n", strerror(ret)); |
| break; |
| } else |
| ipt->state = TD_CREATED; |
| |
| if ((ret = pthread_detach(ipt->thread))) { |
| /* log error and let the thread spin */ |
| log_err("fio: pthread_detatch %s\n", strerror(ret)); |
| } |
| } |
| |
| /* |
| * let good threads continue so that they can exit |
| * if errors on other threads occurred previously. |
| */ |
| for (i = 0; i < ipc.nr_cpus; i++) { |
| ipt = &ipc.ipts[i]; |
| pthread_mutex_unlock(&ipt->init_lock); |
| } |
| |
| if (ipc.status == IDLE_PROF_STATUS_ABORT) |
| return; |
| |
| /* wait for calibration to finish */ |
| for (i = 0; i < ipc.nr_cpus; i++) { |
| ipt = &ipc.ipts[i]; |
| pthread_mutex_lock(&ipt->init_lock); |
| while ((ipt->state != TD_EXITED) && |
| (ipt->state!=TD_INITIALIZED)) { |
| fio_gettime(&tp, NULL); |
| ts.tv_sec = tp.tv_sec + 1; |
| ts.tv_nsec = tp.tv_usec * 1000; |
| pthread_cond_timedwait(&ipt->cond, &ipt->init_lock, &ts); |
| } |
| pthread_mutex_unlock(&ipt->init_lock); |
| |
| /* |
| * any thread failed to initialize would abort other threads |
| * later after fio_idle_prof_start. |
| */ |
| if (ipt->state == TD_EXITED) |
| ipc.status = IDLE_PROF_STATUS_ABORT; |
| } |
| |
| if (ipc.status != IDLE_PROF_STATUS_ABORT) |
| calibration_stats(); |
| else |
| ipc.cali_mean = ipc.cali_stddev = 0.0; |
| |
| if (ipc.opt == IDLE_PROF_OPT_CALI) |
| ipc.status = IDLE_PROF_STATUS_CALI_STOP; |
| } |
| |
| void fio_idle_prof_start(void) |
| { |
| int i; |
| struct idle_prof_thread *ipt; |
| |
| if (ipc.opt == IDLE_PROF_OPT_NONE) |
| return; |
| |
| /* unlock regardless abort is set or not */ |
| for (i = 0; i < ipc.nr_cpus; i++) { |
| ipt = &ipc.ipts[i]; |
| pthread_mutex_unlock(&ipt->start_lock); |
| } |
| } |
| |
| void fio_idle_prof_stop(void) |
| { |
| int i; |
| uint64_t runt; |
| struct timeval tp; |
| struct timespec ts; |
| struct idle_prof_thread *ipt; |
| |
| if (ipc.opt == IDLE_PROF_OPT_NONE) |
| return; |
| |
| if (ipc.opt == IDLE_PROF_OPT_CALI) |
| return; |
| |
| ipc.status = IDLE_PROF_STATUS_PROF_STOP; |
| |
| /* wait for all threads to exit from profiling */ |
| for (i = 0; i < ipc.nr_cpus; i++) { |
| ipt = &ipc.ipts[i]; |
| pthread_mutex_lock(&ipt->start_lock); |
| while ((ipt->state != TD_EXITED) && |
| (ipt->state!=TD_NOT_CREATED)) { |
| fio_gettime(&tp, NULL); |
| ts.tv_sec = tp.tv_sec + 1; |
| ts.tv_nsec = tp.tv_usec * 1000; |
| /* timed wait in case a signal is not received */ |
| pthread_cond_timedwait(&ipt->cond, &ipt->start_lock, &ts); |
| } |
| pthread_mutex_unlock(&ipt->start_lock); |
| |
| /* calculate idleness */ |
| if (ipc.cali_mean != 0.0) { |
| runt = utime_since(&ipt->tps, &ipt->tpe); |
| ipt->idleness = ipt->loops * ipc.cali_mean / runt; |
| } else |
| ipt->idleness = 0.0; |
| } |
| |
| /* |
| * memory allocations are freed via explicit fio_idle_prof_cleanup |
| * after profiling stats are collected by apps. |
| */ |
| } |
| |
| /* |
| * return system idle percentage when cpu is -1; |
| * return one cpu idle percentage otherwise. |
| */ |
| static double fio_idle_prof_cpu_stat(int cpu) |
| { |
| int i, nr_cpus = ipc.nr_cpus; |
| struct idle_prof_thread *ipt; |
| double p = 0.0; |
| |
| if (ipc.opt == IDLE_PROF_OPT_NONE) |
| return 0.0; |
| |
| if ((cpu >= nr_cpus) || (cpu < -1)) { |
| log_err("fio: idle profiling invalid cpu index\n"); |
| return 0.0; |
| } |
| |
| if (cpu == -1) { |
| for (i = 0; i < nr_cpus; i++) { |
| ipt = &ipc.ipts[i]; |
| p += ipt->idleness; |
| } |
| p /= nr_cpus; |
| } else { |
| ipt = &ipc.ipts[cpu]; |
| p = ipt->idleness; |
| } |
| |
| return p * 100.0; |
| } |
| |
| static void fio_idle_prof_cleanup(void) |
| { |
| if (ipc.ipts) { |
| free(ipc.ipts); |
| ipc.ipts = NULL; |
| } |
| |
| if (ipc.buf) { |
| free(ipc.buf); |
| ipc.buf = NULL; |
| } |
| } |
| |
| int fio_idle_prof_parse_opt(const char *args) |
| { |
| ipc.opt = IDLE_PROF_OPT_NONE; /* default */ |
| |
| if (!args) { |
| log_err("fio: empty idle-prof option string\n"); |
| return -1; |
| } |
| |
| #if defined(FIO_HAVE_CPU_AFFINITY) && defined(CONFIG_SCHED_IDLE) |
| if (strcmp("calibrate", args) == 0) { |
| ipc.opt = IDLE_PROF_OPT_CALI; |
| fio_idle_prof_init(); |
| fio_idle_prof_start(); |
| fio_idle_prof_stop(); |
| show_idle_prof_stats(FIO_OUTPUT_NORMAL, NULL); |
| return 1; |
| } else if (strcmp("system", args) == 0) { |
| ipc.opt = IDLE_PROF_OPT_SYSTEM; |
| return 0; |
| } else if (strcmp("percpu", args) == 0) { |
| ipc.opt = IDLE_PROF_OPT_PERCPU; |
| return 0; |
| } else { |
| log_err("fio: incorrect idle-prof option: %s\n", args); |
| return -1; |
| } |
| #else |
| log_err("fio: idle-prof not supported on this platform\n"); |
| return -1; |
| #endif |
| } |
| |
| void show_idle_prof_stats(int output, struct json_object *parent) |
| { |
| int i, nr_cpus = ipc.nr_cpus; |
| struct json_object *tmp; |
| char s[MAX_CPU_STR_LEN]; |
| |
| if (output == FIO_OUTPUT_NORMAL) { |
| if (ipc.opt > IDLE_PROF_OPT_CALI) |
| log_info("\nCPU idleness:\n"); |
| else if (ipc.opt == IDLE_PROF_OPT_CALI) |
| log_info("CPU idleness:\n"); |
| |
| if (ipc.opt >= IDLE_PROF_OPT_SYSTEM) |
| log_info(" system: %3.2f%%\n", fio_idle_prof_cpu_stat(-1)); |
| |
| if (ipc.opt == IDLE_PROF_OPT_PERCPU) { |
| log_info(" percpu: %3.2f%%", fio_idle_prof_cpu_stat(0)); |
| for (i = 1; i < nr_cpus; i++) |
| log_info(", %3.2f%%", fio_idle_prof_cpu_stat(i)); |
| log_info("\n"); |
| } |
| |
| if (ipc.opt >= IDLE_PROF_OPT_CALI) { |
| log_info(" unit work: mean=%3.2fus,", ipc.cali_mean); |
| log_info(" stddev=%3.2f\n", ipc.cali_stddev); |
| } |
| |
| /* dynamic mem allocations can now be freed */ |
| if (ipc.opt != IDLE_PROF_OPT_NONE) |
| fio_idle_prof_cleanup(); |
| |
| return; |
| } |
| |
| if ((ipc.opt != IDLE_PROF_OPT_NONE) && (output == FIO_OUTPUT_JSON)) { |
| if (!parent) |
| return; |
| |
| tmp = json_create_object(); |
| if (!tmp) |
| return; |
| |
| json_object_add_value_object(parent, "cpu_idleness", tmp); |
| json_object_add_value_float(tmp, "system", fio_idle_prof_cpu_stat(-1)); |
| |
| if (ipc.opt == IDLE_PROF_OPT_PERCPU) { |
| for (i = 0; i < nr_cpus; i++) { |
| snprintf(s, MAX_CPU_STR_LEN, "cpu-%d", i); |
| json_object_add_value_float(tmp, s, fio_idle_prof_cpu_stat(i)); |
| } |
| } |
| |
| json_object_add_value_float(tmp, "unit_mean", ipc.cali_mean); |
| json_object_add_value_float(tmp, "unit_stddev", ipc.cali_stddev); |
| |
| fio_idle_prof_cleanup(); |
| } |
| } |