kernel-ark/include/linux/sunrpc/svcsock.h
Greg Banks 7b2b1fee30 [PATCH] knfsd: knfsd: cache ipmap per TCP socket
Speed up high call-rate workloads by caching the struct ip_map for the peer on
the connected struct svc_sock instead of looking it up in the ip_map cache
hashtable on every call.  This helps workloads using AUTH_SYS authentication
over TCP.

Testing was on a 4 CPU 4 NIC Altix using 4 IRIX clients, each with 16
synthetic client threads simulating an rsync (i.e.  recursive directory
listing) workload reading from an i386 RH9 install image (161480 regular files
in 10841 directories) on the server.  That tree is small enough to fill in the
server's RAM so no disk traffic was involved.  This setup gives a sustained
call rate in excess of 60000 calls/sec before being CPU-bound on the server.

Profiling showed strcmp(), called from ip_map_match(), was taking 4.8% of each
CPU, and ip_map_lookup() was taking 2.9%.  This patch drops both contribution
into the profile noise.

Note that the above result overstates this value of this patch for most
workloads.  The synthetic clients are all using separate IP addresses, so
there are 64 entries in the ip_map cache hash.  Because the kernel measured
contained the bug fixed in commit

commit 1f1e030bf7

and was running on 64bit little-endian machine, probably all of those 64
entries were on a single chain, thus increasing the cost of ip_map_lookup().

With a modern kernel you would need more clients to see the same amount of
performance improvement.  This patch has helped to scale knfsd to handle a
deployment with 2000 NFS clients.

Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04 07:55:16 -07:00

78 lines
2.4 KiB
C

/*
* linux/include/linux/sunrpc/svcsock.h
*
* RPC server socket I/O.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef SUNRPC_SVCSOCK_H
#define SUNRPC_SVCSOCK_H
#include <linux/sunrpc/svc.h>
/*
* RPC server socket.
*/
struct svc_sock {
struct list_head sk_ready; /* list of ready sockets */
struct list_head sk_list; /* list of all sockets */
struct socket * sk_sock; /* berkeley socket layer */
struct sock * sk_sk; /* INET layer */
struct svc_pool * sk_pool; /* current pool iff queued */
struct svc_serv * sk_server; /* service for this socket */
atomic_t sk_inuse; /* use count */
unsigned long sk_flags;
#define SK_BUSY 0 /* enqueued/receiving */
#define SK_CONN 1 /* conn pending */
#define SK_CLOSE 2 /* dead or dying */
#define SK_DATA 3 /* data pending */
#define SK_TEMP 4 /* temp (TCP) socket */
#define SK_DEAD 6 /* socket closed */
#define SK_CHNGBUF 7 /* need to change snd/rcv buffer sizes */
#define SK_DEFERRED 8 /* request on sk_deferred */
#define SK_OLD 9 /* used for temp socket aging mark+sweep */
#define SK_DETACHED 10 /* detached from tempsocks list */
atomic_t sk_reserved; /* space on outq that is reserved */
spinlock_t sk_defer_lock; /* protects sk_deferred */
struct list_head sk_deferred; /* deferred requests that need to
* be revisted */
struct mutex sk_mutex; /* to serialize sending data */
int (*sk_recvfrom)(struct svc_rqst *rqstp);
int (*sk_sendto)(struct svc_rqst *rqstp);
/* We keep the old state_change and data_ready CB's here */
void (*sk_ostate)(struct sock *);
void (*sk_odata)(struct sock *, int bytes);
void (*sk_owspace)(struct sock *);
/* private TCP part */
int sk_reclen; /* length of record */
int sk_tcplen; /* current read length */
time_t sk_lastrecv; /* time of last received request */
/* cache of various info for TCP sockets */
void *sk_info_authunix;
};
/*
* Function prototypes.
*/
int svc_makesock(struct svc_serv *, int, unsigned short);
void svc_delete_socket(struct svc_sock *);
int svc_recv(struct svc_rqst *, long);
int svc_send(struct svc_rqst *);
void svc_drop(struct svc_rqst *);
void svc_sock_update_bufs(struct svc_serv *serv);
int svc_sock_names(char *buf, struct svc_serv *serv, char *toclose);
int svc_addsock(struct svc_serv *serv,
int fd,
char *name_return,
int *proto);
#endif /* SUNRPC_SVCSOCK_H */