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 unsigned long utime_since(struct timeval *s, struct timeval *e)
  10 {
  11         long sec, usec, ret;
  12
  13         sec = e->tv_sec - s->tv_sec;
  14         usec = e->tv_usec - s->tv_usec;
  15         if (sec > 0 && usec < 0) {
  16                 sec--;
  17                 usec += 1000000;
  18         }
  19
  20         sec *= 1000000UL;
  21         ret = sec + usec;
  22
  23         /*
  24          * time warp bug on some kernels?
  25          */
  26         if (ret < 0)
  27                 ret = 0;
  28
  29         return ret;
  30 }
  31
  32 unsigned long utime_since_now(struct timeval *s)
  33 {
  34         struct timeval t;
  35
  36         fio_gettime(&t, NULL);
  37         return utime_since(s, &t);
  38 }
  39
  40 unsigned long mtime_since(struct timeval *s, struct timeval *e)
  41 {
  42         long sec, usec, ret;
  43
  44         sec = e->tv_sec - s->tv_sec;
  45         usec = e->tv_usec - s->tv_usec;
  46         if (sec > 0 && usec < 0) {
  47                 sec--;
  48                 usec += 1000000;
  49         }
  50
  51         sec *= 1000UL;
  52         usec /= 1000UL;
  53         ret = sec + usec;
  54
  55         /*
  56          * time warp bug on some kernels?
  57          */
  58         if (ret < 0)
  59                 ret = 0;
  60
  61         return ret;
  62 }
  63
  64 unsigned long mtime_since_now(struct timeval *s)
  65 {
  66         struct timeval t;
  67         void *p = __builtin_return_address(0);
  68
  69         fio_gettime(&t, p);
  70         return mtime_since(s, &t);
  71 }
  72
  73 unsigned long time_since_now(struct timeval *s)
  74 {
  75         return mtime_since_now(s) / 1000;
  76 }
  77
  78 /*
  79  * busy looping version for the last few usec
  80  */
  81 void __usec_sleep(unsigned int usec)
  82 {
  83         struct timeval start;
  84
  85         fio_gettime(&start, NULL);
  86         while (utime_since_now(&start) < usec)
  87                 nop;
  88 }
  89
  90 void usec_sleep(struct thread_data *td, unsigned long usec)
  91 {
  92         struct timespec req;
  93         struct timeval tv;
  94
  95         do {
  96                 unsigned long ts = usec;
  97
  98                 if (usec < ns_granularity) {
  99                         __usec_sleep(usec);
 100                         break;
 101                 }
 102
 103                 ts = usec - ns_granularity;
 104
 105                 if (ts >= 1000000) {
 106                         req.tv_sec = ts / 1000000;
 107                         ts -= 1000000 * req.tv_sec;
 108                 } else
 109                         req.tv_sec = 0;
 110
 111                 req.tv_nsec = ts * 1000;
 112                 fio_gettime(&tv, NULL);
 113
 114                 if (nanosleep(&req, NULL) < 0)
 115                         break;
 116
 117                 ts = utime_since_now(&tv);
 118                 if (ts >= usec)
 119                         break;
 120
 121                 usec -= ts;
 122         } while (!td->terminate);
 123 }
 124
 125 void rate_throttle(struct thread_data *td, unsigned long time_spent,
 126                    unsigned int bytes)
 127 {
 128         unsigned long usec_cycle;
 129         unsigned int bs;
 130
 131         if (!td->o.rate && !td->o.rate_iops)
 132                 return;
 133
 134         if (td_rw(td))
 135                 bs = td->o.rw_min_bs;
 136         else if (td_read(td))
 137                 bs = td->o.min_bs[DDIR_READ];
 138         else
 139                 bs = td->o.min_bs[DDIR_WRITE];
 140
 141         usec_cycle = td->rate_usec_cycle * (bytes / bs);
 142
 143         if (time_spent < usec_cycle) {
 144                 unsigned long s = usec_cycle - time_spent;
 145
 146                 td->rate_pending_usleep += s;
 147
 148                 if (td->rate_pending_usleep >= 100000) {
 149                         struct timeval t;
 150
 151                         fio_gettime(&t, NULL);
 152                         usec_sleep(td, td->rate_pending_usleep);
 153                         td->rate_pending_usleep -= utime_since_now(&t);
 154                 }
 155         } else {
 156                 long overtime = time_spent - usec_cycle;
 157
 158                 td->rate_pending_usleep -= overtime;
 159         }
 160 }
 161
 162 unsigned long mtime_since_genesis(void)
 163 {
 164         return mtime_since_now(&genesis);
 165 }
 166
 167 static void fio_init time_init(void)
 168 {
 169         int i;
 170
 171         /*
 172          * Check the granularity of the nanosleep function
 173          */
 174         for (i = 0; i < 10; i++) {
 175                 struct timeval tv;
 176                 struct timespec ts;
 177                 unsigned long elapsed;
 178
 179                 fio_gettime(&tv, NULL);
 180                 ts.tv_sec = 0;
 181                 ts.tv_nsec = 1000;
 182
 183                 nanosleep(&ts, NULL);
 184                 elapsed = utime_since_now(&tv);
 185
 186                 if (elapsed > ns_granularity)
 187                         ns_granularity = elapsed;
 188         }
 189 }
 190
 191 void set_genesis_time(void)
 192 {
 193         fio_gettime(&genesis, NULL);
 194 }
 195
 196 void fill_start_time(struct timeval *t)
 197 {
 198         memcpy(t, &genesis, sizeof(genesis));
 199 }