X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=helper_thread.c;h=b9b83db3057435f6fd2918d84cc3e96bdb7c4252;hb=ebd9b4dd690808f720712b9c1a1288ae0742f361;hp=40f99a5e8eba9bd33e56172031f80b143cd02e45;hpb=335210df931c79d59f93424e64c0623e59b18754;p=fio.git diff --git a/helper_thread.c b/helper_thread.c index 40f99a5e..b9b83db3 100644 --- a/helper_thread.c +++ b/helper_thread.c @@ -1,16 +1,27 @@ #include +#include +#ifdef CONFIG_HAVE_TIMERFD_CREATE +#include +#endif #ifdef CONFIG_VALGRIND_DEV #include #else #define DRD_IGNORE_VAR(x) do { } while (0) #endif +#ifdef WIN32 +#include "os/os-windows.h" +#endif + #include "fio.h" #include "smalloc.h" #include "helper_thread.h" #include "steadystate.h" #include "pshared.h" +static int sleep_accuracy_ms; +static int timerfd = -1; + enum action { A_EXIT = 1, A_RESET = 2, @@ -25,6 +36,13 @@ static struct helper_data { struct fio_sem *startup_sem; } *helper_data; +struct interval_timer { + const char *name; + struct timespec expires; + uint32_t interval_ms; + int (*func)(void); +}; + void helper_thread_destroy(void) { if (!helper_data) @@ -140,6 +158,23 @@ void helper_thread_exit(void) pthread_join(helper_data->thread, NULL); } +/* Resets timers and returns the time in milliseconds until the next event. */ +static int reset_timers(struct interval_timer timer[], int num_timers, + struct timespec *now) +{ + uint32_t msec_to_next_event = INT_MAX; + int i; + + for (i = 0; i < num_timers; ++i) { + timer[i].expires = *now; + timespec_add_msec(&timer[i].expires, timer[i].interval_ms); + msec_to_next_event = min_not_zero(msec_to_next_event, + timer[i].interval_ms); + } + + return msec_to_next_event; +} + /* * Waits for an action from fd during at least timeout_ms. `fd` must be in * non-blocking mode. @@ -152,6 +187,7 @@ static uint8_t wait_for_action(int fd, unsigned int timeout_ms) }; fd_set rfds, efds; uint8_t action = 0; + uint64_t exp; int res; res = read_from_pipe(fd, &action, sizeof(action)); @@ -161,7 +197,25 @@ static uint8_t wait_for_action(int fd, unsigned int timeout_ms) FD_SET(fd, &rfds); FD_ZERO(&efds); FD_SET(fd, &efds); - res = select(fd + 1, &rfds, NULL, &efds, &timeout); +#ifdef CONFIG_HAVE_TIMERFD_CREATE + { + /* + * If the timer frequency is 100 Hz, select() will round up + * `timeout` to the next multiple of 1 / 100 Hz = 10 ms. Hence + * use a high-resolution timer if possible to increase + * select() timeout accuracy. + */ + struct itimerspec delta = {}; + + delta.it_value.tv_sec = timeout.tv_sec; + delta.it_value.tv_nsec = timeout.tv_usec * 1000; + res = timerfd_settime(timerfd, 0, &delta, NULL); + assert(res == 0); + FD_SET(timerfd, &rfds); + } +#endif + res = select(max(fd, timerfd) + 1, &rfds, NULL, &efds, + timerfd >= 0 ? NULL : &timeout); if (res < 0) { log_err("fio: select() call in helper thread failed: %s", strerror(errno)); @@ -169,51 +223,98 @@ static uint8_t wait_for_action(int fd, unsigned int timeout_ms) } if (FD_ISSET(fd, &rfds)) read_from_pipe(fd, &action, sizeof(action)); + if (timerfd >= 0 && FD_ISSET(timerfd, &rfds)) { + res = read(timerfd, &exp, sizeof(exp)); + assert(res == sizeof(exp)); + } return action; } -static unsigned int task_helper(struct timespec *last, struct timespec *now, unsigned int period, void do_task()) +/* + * Verify whether or not timer @it has expired. If timer @it has expired, call + * @it->func(). @now is the current time. @msec_to_next_event is an + * input/output parameter that represents the time until the next event. + */ +static int eval_timer(struct interval_timer *it, const struct timespec *now, + unsigned int *msec_to_next_event) { - unsigned int next, since; - - since = mtime_since(last, now); - if (since >= period || period - since < 10) { - do_task(); - timespec_add_msec(last, since); - if (since > period) - next = period - (since - period); - else - next = period; - } else - next = period - since; - - return next; + int64_t delta_ms; + bool expired; + + /* interval == 0 means that the timer is disabled. */ + if (it->interval_ms == 0) + return 0; + + delta_ms = rel_time_since(now, &it->expires); + expired = delta_ms <= sleep_accuracy_ms; + if (expired) { + timespec_add_msec(&it->expires, it->interval_ms); + delta_ms = rel_time_since(now, &it->expires); + if (delta_ms < it->interval_ms - sleep_accuracy_ms || + delta_ms > it->interval_ms + sleep_accuracy_ms) { + dprint(FD_HELPERTHREAD, + "%s: delta = %" PRIi64 " <> %u. Clock jump?\n", + it->name, delta_ms, it->interval_ms); + delta_ms = it->interval_ms; + it->expires = *now; + timespec_add_msec(&it->expires, it->interval_ms); + } + } + *msec_to_next_event = min((unsigned int)delta_ms, *msec_to_next_event); + return expired ? it->func() : 0; } static void *helper_thread_main(void *data) { struct helper_data *hd = data; - unsigned int msec_to_next_event, next_log, next_si = status_interval; - unsigned int next_ss = STEADYSTATE_MSEC; - struct timespec ts, last_du, last_ss, last_si; + unsigned int msec_to_next_event, next_log; + struct interval_timer timer[] = { + { + .name = "disk_util", + .interval_ms = DISK_UTIL_MSEC, + .func = update_io_ticks, + }, + { + .name = "status_interval", + .interval_ms = status_interval, + .func = __show_running_run_stats, + }, + { + .name = "steadystate", + .interval_ms = steadystate_enabled ? STEADYSTATE_MSEC : + 0, + .func = steadystate_check, + } + }; + struct timespec ts; + long clk_tck; int ret = 0; + os_clk_tck(&clk_tck); + + dprint(FD_HELPERTHREAD, "clk_tck = %ld\n", clk_tck); + assert(clk_tck > 0); + sleep_accuracy_ms = (1000 + clk_tck - 1) / clk_tck; + +#ifdef CONFIG_HAVE_TIMERFD_CREATE + timerfd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK); + assert(timerfd >= 0); + sleep_accuracy_ms = 1; +#endif + sk_out_assign(hd->sk_out); /* Let another thread handle signals. */ block_signals(); fio_get_mono_time(&ts); - memcpy(&last_du, &ts, sizeof(ts)); - memcpy(&last_ss, &ts, sizeof(ts)); - memcpy(&last_si, &ts, sizeof(ts)); + msec_to_next_event = reset_timers(timer, FIO_ARRAY_SIZE(timer), &ts); fio_sem_up(hd->startup_sem); - msec_to_next_event = DISK_UTIL_MSEC; while (!ret && !hd->exit) { - uint64_t since_du; uint8_t action; + int i; action = wait_for_action(hd->pipe[0], msec_to_next_event); if (action == A_EXIT) @@ -221,46 +322,36 @@ static void *helper_thread_main(void *data) fio_get_mono_time(&ts); - if (action == A_RESET) { - last_du = ts; - last_ss = ts; - } + msec_to_next_event = INT_MAX; + + if (action == A_RESET) + msec_to_next_event = reset_timers(timer, + FIO_ARRAY_SIZE(timer), &ts); - since_du = mtime_since(&last_du, &ts); - if (since_du >= DISK_UTIL_MSEC || DISK_UTIL_MSEC - since_du < 10) { - ret = update_io_ticks(); - timespec_add_msec(&last_du, DISK_UTIL_MSEC); - msec_to_next_event = DISK_UTIL_MSEC; - if (since_du >= DISK_UTIL_MSEC) - msec_to_next_event -= (since_du - DISK_UTIL_MSEC); - } else - msec_to_next_event = DISK_UTIL_MSEC - since_du; + for (i = 0; i < FIO_ARRAY_SIZE(timer); ++i) + ret = eval_timer(&timer[i], &ts, &msec_to_next_event); if (action == A_DO_STAT) __show_running_run_stats(); - if (status_interval) { - next_si = task_helper(&last_si, &ts, status_interval, __show_running_run_stats); - msec_to_next_event = min(next_si, msec_to_next_event); - } - next_log = calc_log_samples(); if (!next_log) next_log = DISK_UTIL_MSEC; - if (steadystate_enabled) { - next_ss = task_helper(&last_ss, &ts, STEADYSTATE_MSEC, steadystate_check); - msec_to_next_event = min(next_ss, msec_to_next_event); - } - msec_to_next_event = min(next_log, msec_to_next_event); - dprint(FD_HELPERTHREAD, "next_si: %u, next_ss: %u, next_log: %u, msec_to_next_event: %u\n", - next_si, next_ss, next_log, msec_to_next_event); + dprint(FD_HELPERTHREAD, + "next_log: %u, msec_to_next_event: %u\n", + next_log, msec_to_next_event); if (!is_backend) print_thread_status(); } + if (timerfd >= 0) { + close(timerfd); + timerfd = -1; + } + fio_writeout_logs(false); sk_out_drop();