--- /dev/null
+#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 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;
+
+#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 ((retval=fio_setaffinity(gettid(), cpu_mask)) == -1)
+ log_err("fio: fio_setaffinity failed\n");
+#else
+ retval = -1;
+ log_err("fio: fio_setaffinity not supported\n");
+#endif
+ 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(FIO_HAVE_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;
+}
+
+/* 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;
+}
+
+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(FIO_HAVE_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\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();
+
+ return;
+ }
+}
projects / fio.git / commitdiff