linux/sunrpc/timer.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  *  linux/include/linux/sunrpc/timer.h
0004  *
0005  *  Declarations for the RPC transport timer.
0006  *
0007  *  Copyright (C) 2002 Trond Myklebust <trond.myklebust@fys.uio.no>
0008  */
0009
0010 #ifndef _LINUX_SUNRPC_TIMER_H
0011 #define _LINUX_SUNRPC_TIMER_H
0012
0013 #include <linux/atomic.h>
0014
0015 struct rpc_rtt {
0016     unsigned long timeo;    /* default timeout value */
0017     unsigned long srtt[5];  /* smoothed round trip time << 3 */
0018     unsigned long sdrtt[5]; /* smoothed medium deviation of RTT */
0019     int ntimeouts[5];   /* Number of timeouts for the last request */
0020 };
0021
0022
0023 extern void rpc_init_rtt(struct rpc_rtt *rt, unsigned long timeo);
0024 extern void rpc_update_rtt(struct rpc_rtt *rt, unsigned timer, long m);
0025 extern unsigned long rpc_calc_rto(struct rpc_rtt *rt, unsigned timer);
0026
0027 static inline void rpc_set_timeo(struct rpc_rtt *rt, int timer, int ntimeo)
0028 {
0029     int *t;
0030     if (!timer)
0031         return;
0032     t = &rt->ntimeouts[timer-1];
0033     if (ntimeo < *t) {
0034         if (*t > 0)
0035             (*t)--;
0036     } else {
0037         if (ntimeo > 8)
0038             ntimeo = 8;
0039         *t = ntimeo;
0040     }
0041 }
0042
0043 static inline int rpc_ntimeo(struct rpc_rtt *rt, int timer)
0044 {
0045     if (!timer)
0046         return 0;
0047     return rt->ntimeouts[timer-1];
0048 }
0049
0050 #endif /* _LINUX_SUNRPC_TIMER_H */