include/linux/sunrpc/timer.h

   1 /*
   2  *  linux/include/linux/sunrpc/timer.h
   3  *
   4  *  Declarations for the RPC transport timer.
   5  *
   6  *  Copyright (C) 2002 Trond Myklebust <trond.myklebust@fys.uio.no>
   7  */
   8
   9 #ifndef _LINUX_SUNRPC_TIMER_H
  10 #define _LINUX_SUNRPC_TIMER_H
  11
  12 #include <linux/atomic.h>
  13
  14 struct rpc_rtt {
  15         unsigned long timeo;    /* default timeout value */
  16         unsigned long srtt[5];  /* smoothed round trip time << 3 */
  17         unsigned long sdrtt[5]; /* smoothed medium deviation of RTT */
  18         int ntimeouts[5];       /* Number of timeouts for the last request */
  19 };
  20
  21
  22 extern void rpc_init_rtt(struct rpc_rtt *rt, unsigned long timeo);
  23 extern void rpc_update_rtt(struct rpc_rtt *rt, unsigned timer, long m);
  24 extern unsigned long rpc_calc_rto(struct rpc_rtt *rt, unsigned timer);
  25
  26 static inline void rpc_set_timeo(struct rpc_rtt *rt, int timer, int ntimeo)
  27 {
  28         int *t;
  29         if (!timer)
  30                 return;
  31         t = &rt->ntimeouts[timer-1];
  32         if (ntimeo < *t) {
  33                 if (*t > 0)
  34                         (*t)--;
  35         } else {
  36                 if (ntimeo > 8)
  37                         ntimeo = 8;
  38                 *t = ntimeo;
  39         }
  40 }
  41
  42 static inline int rpc_ntimeo(struct rpc_rtt *rt, int timer)
  43 {
  44         if (!timer)
  45                 return 0;
  46         return rt->ntimeouts[timer-1];
  47 }
  48
  49 #endif /* _LINUX_SUNRPC_TIMER_H */