freebsd-skq/sys/fs/nfs/nfsrvcache.h
rmacklem 802b1728d8 Fix several performance related issues in the new NFS server's
DRC for NFS over TCP.
- Increase the size of the hash tables.
- Create a separate mutex for each hash list of the TCP hash table.
- Single thread the code that deletes stale cache entries.
- Add a tunable called vfs.nfsd.tcphighwater, which can be increased
  to allow the cache to grow larger, avoiding the overhead of frequent
  scans to delete stale cache entries.
  (The default value will result in frequent scans to delete stale cache
   entries, analagous to what the pre-patched code does.)
- Add a tunable called vfs.nfsd.cachetcp that can be used to disable
  DRC caching for NFS over TCP, since the old NFS server didn't DRC cache TCP.
It also adjusts the size of nfsrc_floodlevel dynamically, so that it is
always greater than vfs.nfsd.tcphighwater.

For UDP the algorithm remains the same as the pre-patched code, but the
tunable vfs.nfsd.udphighwater can be used to allow the cache to grow
larger and reduce the overhead caused by frequent scans for stale entries.
UDP also uses a larger hash table size than the pre-patched code.

Reported by:	wollman
Tested by:	wollman (earlier version of patch)
Submitted by:	ivoras (earlier patch)
Reviewed by:	jhb (earlier version of patch)
MFC after:	1 month
2013-08-14 21:11:26 +00:00

116 lines
3.6 KiB
C

/*-
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _NFS_NFSRVCACHE_H_
#define _NFS_NFSRVCACHE_H_
/*
* Definitions for the server recent request cache
*/
#define NFSRVCACHE_MAX_SIZE 2048
#define NFSRVCACHE_MIN_SIZE 64
#define NFSRVCACHE_HASHSIZE 500
/* Cache table entry. */
struct nfsrvcache {
LIST_ENTRY(nfsrvcache) rc_hash; /* Hash chain */
TAILQ_ENTRY(nfsrvcache) rc_lru; /* UDP lru chain */
u_int32_t rc_xid; /* rpc id number */
time_t rc_timestamp; /* Time done */
union {
mbuf_t repmb; /* Reply mbuf list OR */
int repstat; /* Reply status */
} rc_un;
union {
struct {
union nethostaddr haddr; /* Host address */
} udp;
struct {
u_int64_t sockref;
u_int32_t len;
u_int32_t tcpseq;
int16_t refcnt;
u_int16_t cksum;
time_t cachetime;
} ot;
} rc_un2;
u_int16_t rc_proc; /* rpc proc number */
u_int16_t rc_flag; /* Flag bits */
};
#define rc_reply rc_un.repmb
#define rc_status rc_un.repstat
#define rc_inet rc_un2.udp.haddr.had_inet.s_addr
#define rc_inet6 rc_un2.udp.haddr.had_inet6
#define rc_haddr rc_un2.udp.haddr
#define rc_sockref rc_un2.ot.sockref
#define rc_tcpseq rc_un2.ot.tcpseq
#define rc_refcnt rc_un2.ot.refcnt
#define rc_reqlen rc_un2.ot.len
#define rc_cksum rc_un2.ot.cksum
#define rc_cachetime rc_un2.ot.cachetime
/* Return values */
#define RC_DROPIT 0
#define RC_REPLY 1
#define RC_DOIT 2
/* Flag bits */
#define RC_LOCKED 0x0001
#define RC_WANTED 0x0002
#define RC_REPSTATUS 0x0004
#define RC_REPMBUF 0x0008
#define RC_UDP 0x0010
#define RC_INETIPV6 0x0020
#define RC_INPROG 0x0040
#define RC_TCPSEQ 0x0080
#define RC_NFSV2 0x0100
#define RC_NFSV3 0x0200
#define RC_NFSV4 0x0400
#define RC_NFSVERS (RC_NFSV2 | RC_NFSV3 | RC_NFSV4)
#define RC_REFCNT 0x0800
#define RC_SAMETCPCONN 0x1000
LIST_HEAD(nfsrvhashhead, nfsrvcache);
/* The fine-grained locked cache hash table for TCP. */
struct nfsrchash_bucket {
struct mtx mtx;
char lock_name[16];
struct nfsrvhashhead tbl;
};
#endif /* _NFS_NFSRVCACHE_H_ */