time.c

   1 #include <time.h>
   2 #include <sys/time.h>
   3
   4 #include "fio.h"
   5
   6 static struct timeval genesis;
   7
   8 unsigned long utime_since(struct timeval *s, struct timeval *e)
   9 {
  10         double sec, usec;
  11
  12         sec = e->tv_sec - s->tv_sec;
  13         usec = e->tv_usec - s->tv_usec;
  14         if (sec > 0 && usec < 0) {
  15                 sec--;
  16                 usec += 1000000;
  17         }
  18
  19         sec *= (double) 1000000;
  20
  21         return sec + usec;
  22 }
  23
  24 static unsigned long utime_since_now(struct timeval *s)
  25 {
  26         struct timeval t;
  27
  28         gettimeofday(&t, NULL);
  29         return utime_since(s, &t);
  30 }
  31
  32 unsigned long mtime_since(struct timeval *s, struct timeval *e)
  33 {
  34         double sec, usec;
  35
  36         sec = e->tv_sec - s->tv_sec;
  37         usec = e->tv_usec - s->tv_usec;
  38         if (sec > 0 && usec < 0) {
  39                 sec--;
  40                 usec += 1000000;
  41         }
  42
  43         sec *= (double) 1000;
  44         usec /= (double) 1000;
  45
  46         return sec + usec;
  47 }
  48
  49 unsigned long mtime_since_now(struct timeval *s)
  50 {
  51         struct timeval t;
  52
  53         gettimeofday(&t, NULL);
  54         return mtime_since(s, &t);
  55 }
  56
  57 unsigned long time_since_now(struct timeval *s)
  58 {
  59         return mtime_since_now(s) / 1000;
  60 }
  61
  62 /*
  63  * busy looping version for the last few usec
  64  */
  65 void __usec_sleep(unsigned int usec)
  66 {
  67         struct timeval start;
  68
  69         gettimeofday(&start, NULL);
  70         while (utime_since_now(&start) < usec)
  71                 nop;
  72 }
  73
  74 void usec_sleep(struct thread_data *td, unsigned long usec)
  75 {
  76         struct timespec req, rem;
  77
  78         req.tv_sec = usec / 1000000;
  79         req.tv_nsec = usec * 1000 - req.tv_sec * 1000000;
  80
  81         do {
  82                 if (usec < 5000) {
  83                         __usec_sleep(usec);
  84                         break;
  85                 }
  86
  87                 rem.tv_sec = rem.tv_nsec = 0;
  88                 if (nanosleep(&req, &rem) < 0)
  89                         break;
  90
  91                 if ((rem.tv_sec + rem.tv_nsec) == 0)
  92                         break;
  93
  94                 req.tv_nsec = rem.tv_nsec;
  95                 req.tv_sec = rem.tv_sec;
  96
  97                 usec = rem.tv_sec * 1000000 + rem.tv_nsec / 1000;
  98         } while (!td->terminate);
  99 }
 100
 101 void rate_throttle(struct thread_data *td, unsigned long time_spent,
 102                    unsigned int bytes)
 103 {
 104         unsigned long usec_cycle;
 105
 106         if (!td->rate)
 107                 return;
 108
 109         usec_cycle = td->rate_usec_cycle * (bytes / td->min_bs);
 110
 111         if (time_spent < usec_cycle) {
 112                 unsigned long s = usec_cycle - time_spent;
 113
 114                 td->rate_pending_usleep += s;
 115                 if (td->rate_pending_usleep >= 100000) {
 116                         usec_sleep(td, td->rate_pending_usleep);
 117                         td->rate_pending_usleep = 0;
 118                 }
 119         } else {
 120                 long overtime = time_spent - usec_cycle;
 121
 122                 td->rate_pending_usleep -= overtime;
 123         }
 124 }
 125
 126 unsigned long mtime_since_genesis(void)
 127 {
 128         return mtime_since_now(&genesis);
 129 }
 130
 131 void time_init(void)
 132 {
 133         gettimeofday(&genesis, NULL);
 134 }