time.c

   1 #include <time.h>
   2 #include <sys/time.h>
   3
   4 #include "fio.h"
   5
   6 static struct timeval genesis;
   7 static unsigned long ns_granularity;
   8
   9 /*
  10  * busy looping version for the last few usec
  11  */
  12 uint64_t usec_spin(unsigned int usec)
  13 {
  14         struct timeval start;
  15         uint64_t t;
  16
  17         fio_gettime(&start, NULL);
  18         while ((t = utime_since_now(&start)) < usec)
  19                 nop;
  20
  21         return t;
  22 }
  23
  24 uint64_t usec_sleep(struct thread_data *td, unsigned long usec)
  25 {
  26         struct timespec req;
  27         struct timeval tv;
  28         uint64_t t = 0;
  29
  30         do {
  31                 unsigned long ts = usec;
  32
  33                 if (usec < ns_granularity) {
  34                         t += usec_spin(usec);
  35                         break;
  36                 }
  37
  38                 ts = usec - ns_granularity;
  39
  40                 if (ts >= 1000000) {
  41                         req.tv_sec = ts / 1000000;
  42                         ts -= 1000000 * req.tv_sec;
  43                 } else
  44                         req.tv_sec = 0;
  45
  46                 req.tv_nsec = ts * 1000;
  47                 fio_gettime(&tv, NULL);
  48
  49                 if (nanosleep(&req, NULL) < 0)
  50                         break;
  51
  52                 ts = utime_since_now(&tv);
  53                 t += ts;
  54                 if (ts >= usec)
  55                         break;
  56
  57                 usec -= ts;
  58         } while (!td->terminate);
  59
  60         return t;
  61 }
  62
  63 uint64_t time_since_genesis(void)
  64 {
  65         return time_since_now(&genesis);
  66 }
  67
  68 uint64_t mtime_since_genesis(void)
  69 {
  70         return mtime_since_now(&genesis);
  71 }
  72
  73 uint64_t utime_since_genesis(void)
  74 {
  75         return utime_since_now(&genesis);
  76 }
  77
  78 int in_ramp_time(struct thread_data *td)
  79 {
  80         return td->o.ramp_time && !td->ramp_time_over;
  81 }
  82
  83 int ramp_time_over(struct thread_data *td)
  84 {
  85         struct timeval tv;
  86
  87         if (!td->o.ramp_time || td->ramp_time_over)
  88                 return 1;
  89
  90         fio_gettime(&tv, NULL);
  91         if (utime_since(&td->epoch, &tv) >= td->o.ramp_time) {
  92                 td->ramp_time_over = 1;
  93                 reset_all_stats(td);
  94                 td_set_runstate(td, TD_RAMP);
  95                 return 1;
  96         }
  97
  98         return 0;
  99 }
 100
 101 void fio_time_init(void)
 102 {
 103         int i;
 104
 105         fio_clock_init();
 106
 107         /*
 108          * Check the granularity of the nanosleep function
 109          */
 110         for (i = 0; i < 10; i++) {
 111                 struct timeval tv;
 112                 struct timespec ts;
 113                 unsigned long elapsed;
 114
 115                 fio_gettime(&tv, NULL);
 116                 ts.tv_sec = 0;
 117                 ts.tv_nsec = 1000;
 118
 119                 nanosleep(&ts, NULL);
 120                 elapsed = utime_since_now(&tv);
 121
 122                 if (elapsed > ns_granularity)
 123                         ns_granularity = elapsed;
 124         }
 125 }
 126
 127 void set_genesis_time(void)
 128 {
 129         fio_gettime(&genesis, NULL);
 130 }
 131
 132 void fill_start_time(struct timeval *t)
 133 {
 134         memcpy(t, &genesis, sizeof(genesis));
 135 }