LXR linux/include/linux/sunrpc/timer.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 *  linux/include/linux/sunrpc/timer.h
   4 *
   5 *  Declarations for the RPC transport timer.
   6 *
   7 *  Copyright (C) 2002 Trond Myklebust <trond.myklebust@fys.uio.no>
   8 */
   9
  10#ifndef _LINUX_SUNRPC_TIMER_H
  11#define _LINUX_SUNRPC_TIMER_H
  12
  13#include <linux/atomic.h>
  14
  15struct rpc_rtt {
  16        unsigned long timeo;    /* default timeout value */
  17        unsigned long srtt[5];  /* smoothed round trip time << 3 */
  18        unsigned long sdrtt[5]; /* smoothed medium deviation of RTT */
  19        int ntimeouts[5];       /* Number of timeouts for the last request */
  20};
  21
  22
  23extern void rpc_init_rtt(struct rpc_rtt *rt, unsigned long timeo);
  24extern void rpc_update_rtt(struct rpc_rtt *rt, unsigned timer, long m);
  25extern unsigned long rpc_calc_rto(struct rpc_rtt *rt, unsigned timer);
  26
  27static inline void rpc_set_timeo(struct rpc_rtt *rt, int timer, int ntimeo)
  28{
  29        int *t;
  30        if (!timer)
  31                return;
  32        t = &rt->ntimeouts[timer-1];
  33        if (ntimeo < *t) {
  34                if (*t > 0)
  35                        (*t)--;
  36        } else {
  37                if (ntimeo > 8)
  38                        ntimeo = 8;
  39                *t = ntimeo;
  40        }
  41}
  42
  43static inline int rpc_ntimeo(struct rpc_rtt *rt, int timer)
  44{
  45        if (!timer)
  46                return 0;
  47        return rt->ntimeouts[timer-1];
  48}
  49
  50#endif /* _LINUX_SUNRPC_TIMER_H */
  51