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