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nfsstat.c revision 1.19
      1 /*	$NetBSD: nfsstat.c,v 1.19 2004/08/26 13:29:05 yamt Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1983, 1989, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Rick Macklem at The University of Guelph.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #include <sys/cdefs.h>
     36 #ifndef lint
     37 __COPYRIGHT("@(#) Copyright (c) 1983, 1989, 1993\n\
     38 	The Regents of the University of California.  All rights reserved.\n");
     39 #endif /* not lint */
     40 
     41 #ifndef lint
     42 #if 0
     43 static char sccsid[] = "from: @(#)nfsstat.c	8.1 (Berkeley) 6/6/93";
     44 #else
     45 __RCSID("$NetBSD: nfsstat.c,v 1.19 2004/08/26 13:29:05 yamt Exp $");
     46 #endif
     47 #endif /* not lint */
     48 
     49 #include <sys/param.h>
     50 #include <sys/mount.h>
     51 #include <sys/sysctl.h>
     52 
     53 #include <nfs/rpcv2.h>
     54 #include <nfs/nfsproto.h>
     55 #include <nfs/nfs.h>
     56 
     57 #include <ctype.h>
     58 #include <err.h>
     59 #include <errno.h>
     60 #include <fcntl.h>
     61 #include <kvm.h>
     62 #include <limits.h>
     63 #include <nlist.h>
     64 #include <paths.h>
     65 #include <signal.h>
     66 #include <stdlib.h>
     67 #include <stdio.h>
     68 #include <string.h>
     69 #include <unistd.h>
     70 
     71 struct nlist nl[] = {
     72 #define	N_NFSSTAT	0
     73 	{ "_nfsstats" },
     74 	{ "" },
     75 };
     76 
     77 #define	MASK(a)	(1 << NFSPROC_##a)
     78 #define ALLMASK								\
     79 	(MASK(GETATTR) | MASK(SETATTR) | MASK(LOOKUP) | MASK(READ) |	\
     80 	MASK(WRITE) | MASK(RENAME)| MASK(ACCESS) | MASK(READDIR) |	\
     81 	MASK(READDIRPLUS))
     82 #define	OTHERMASK	(((1 << NFS_NPROCS) - 1) & ~ALLMASK)
     83 const struct shortprocs {
     84 	int mask;
     85 	const char *name;
     86 } shortprocs[] = {
     87 	{MASK(GETATTR),	"Getattr"},
     88 	{MASK(SETATTR),	"Setattr"},
     89 	{MASK(LOOKUP),	"Lookup"},
     90 	{MASK(READ),	"Read"},
     91 	{MASK(WRITE),	"Write"},
     92 	{MASK(RENAME),	"Rename"},
     93 	{MASK(ACCESS),	"Access"},
     94 	{MASK(READDIR) | MASK(READDIRPLUS), "Readdir"},
     95 	{OTHERMASK, "Others"},
     96 };
     97 
     98 #define	NSHORTPROC	(sizeof(shortprocs)/sizeof(shortprocs[0]))
     99 
    100 void	catchalarm __P((int));
    101 void	getstats __P((struct nfsstats *));
    102 void	intpr __P((void));
    103 int	main __P((int, char **));
    104 void	printhdr __P((void));
    105 void	sidewaysintpr __P((u_int));
    106 void	usage __P((void));
    107 
    108 kvm_t  *kd;
    109 int     printall, clientinfo, serverinfo;
    110 u_long	nfsstataddr;
    111 
    112 int
    113 main(argc, argv)
    114 	int argc;
    115 	char **argv;
    116 {
    117 	u_int interval;
    118 	int ch;
    119 	char *memf, *nlistf;
    120 	char errbuf[_POSIX2_LINE_MAX];
    121 
    122 	interval = 0;
    123 	memf = nlistf = NULL;
    124 	printall = 1;
    125 	while ((ch = getopt(argc, argv, "M:N:w:cs")) != -1)
    126 		switch(ch) {
    127 		case 'M':
    128 			memf = optarg;
    129 			break;
    130 		case 'N':
    131 			nlistf = optarg;
    132 			break;
    133 		case 'w':
    134 			interval = atoi(optarg);
    135 			break;
    136 		case 's':
    137 		        serverinfo = 1;
    138 			printall = 0;
    139 			break;
    140 		case 'c':
    141 		        clientinfo = 1;
    142 			printall = 0;
    143 			break;
    144 		case '?':
    145 		default:
    146 			usage();
    147 		}
    148 	argc -= optind;
    149 	argv += optind;
    150 
    151 #define	BACKWARD_COMPATIBILITY
    152 #ifdef	BACKWARD_COMPATIBILITY
    153 	if (*argv) {
    154 		interval = atoi(*argv);
    155 		if (*++argv) {
    156 			nlistf = *argv;
    157 			if (*++argv)
    158 				memf = *argv;
    159 		}
    160 	}
    161 #endif
    162 	if (nlistf || memf) {
    163 		if ((kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf))
    164 		    == 0)
    165 			errx(1, "kvm_openfiles: %s", errbuf);
    166 
    167 		if (kvm_nlist(kd, nl) != 0)
    168 			errx(1, "kvm_nlist: can't get names");
    169 		nfsstataddr = nl[N_NFSSTAT].n_value;
    170 	} else {
    171 		kd = NULL;
    172 	}
    173 
    174 	if (interval)
    175 		sidewaysintpr(interval);
    176 	else
    177 		intpr();
    178 	exit(0);
    179 }
    180 
    181 void
    182 getstats(ns)
    183 	struct nfsstats *ns;
    184 {
    185 	size_t size;
    186 	int mib[3];
    187 
    188 	if (kd) {
    189 		if (kvm_read(kd, (u_long)nfsstataddr, ns, sizeof(*ns))
    190 		    != sizeof(*ns))
    191 			errx(1, "kvm_read failed");
    192 	} else {
    193 		mib[0] = CTL_VFS;
    194 		mib[1] = 2;	/* XXX from CTL_VFS_NAMES in <sys/mount.h> */
    195 		mib[2] = NFS_NFSSTATS;
    196 
    197 		size = sizeof(*ns);
    198 		if (sysctl(mib, 3, ns, &size, NULL, 0) == -1)
    199 			err(1, "sysctl(NFS_NFSSTATS) failed");
    200 	}
    201 }
    202 
    203 /*
    204  * Print a description of the nfs stats.
    205  */
    206 void
    207 intpr()
    208 {
    209 	struct nfsstats nfsstats;
    210 	int64_t	total;
    211 	int	i;
    212 
    213 #define PCT(x,y)	((y) == 0 ? 0 : (int)((int64_t)(x) * 100 / (y)))
    214 #define NUMPCT(x,y)	(x), PCT(x, (x)+(y))
    215 #define	RPCSTAT(x)	(x), PCT(x, total)
    216 
    217 	getstats(&nfsstats);
    218 
    219 	if (printall || clientinfo) {
    220 		total = 0;
    221 		for (i = 0; i < NFS_NPROCS; i++)
    222 			total += nfsstats.rpccnt[i];
    223 		printf("Client Info:\n");
    224 		printf("RPC Counts: (%lld call%s)\n", (long long)total,
    225 		    total == 1 ? "" : "s");
    226 
    227 		printf("%10s  %14s  %14s  %14s  %14s\n",
    228 		    "null", "getattr", "setattr", "lookup", "access");
    229 		printf(
    230 	    "%10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%\n",
    231 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_NULL]),
    232 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_GETATTR]),
    233 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_SETATTR]),
    234 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_LOOKUP]),
    235 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_ACCESS]));
    236 		printf("%10s  %14s  %14s  %14s  %14s\n",
    237 		    "readlink", "read", "write", "create", "mkdir");
    238 		printf(
    239 	    "%10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%\n",
    240 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_READLINK]),
    241 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_READ]),
    242 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_WRITE]),
    243 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_CREATE]),
    244 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_MKDIR]));
    245 		printf("%10s  %14s  %14s  %14s  %14s\n",
    246 		    "symlink", "mknod", "remove", "rmdir", "rename");
    247 		printf(
    248 	    "%10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%\n",
    249 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_SYMLINK]),
    250 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_MKNOD]),
    251 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_REMOVE]),
    252 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_RMDIR]),
    253 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_RENAME]));
    254 		printf("%10s  %14s  %14s  %14s  %14s\n",
    255 		    "link", "readdir", "readdirplus", "fsstat", "fsinfo");
    256 		printf(
    257 	    "%10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%\n",
    258 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_LINK]),
    259 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_READDIR]),
    260 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_READDIRPLUS]),
    261 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_FSSTAT]),
    262 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_FSINFO]));
    263 		printf("%10s  %14s  %14s  %14s  %14s\n",
    264 		    "pathconf", "commit", "getlease", "vacated", "evicted");
    265 		printf(
    266 	    "%10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%\n",
    267 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_PATHCONF]),
    268 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_COMMIT]),
    269 		    RPCSTAT(nfsstats.rpccnt[NQNFSPROC_GETLEASE]),
    270 		    RPCSTAT(nfsstats.rpccnt[NQNFSPROC_VACATED]),
    271 		    RPCSTAT(nfsstats.rpccnt[NQNFSPROC_EVICTED]));
    272 		printf("%10s\n", "noop");
    273 		printf("%10d %2d%%\n",
    274 		    RPCSTAT(nfsstats.rpccnt[NFSPROC_NOOP]));
    275 
    276 		printf("RPC Info:\n");
    277 		printf("%10s  %14s  %14s  %14s  %14s\n",
    278 		    "timeout", "invalid", "unexpected", "retries", "requests");
    279 		printf("%10d  %14d  %14d  %14d  %14d\n",
    280 		    nfsstats.rpctimeouts,
    281 		    nfsstats.rpcinvalid,
    282 		    nfsstats.rpcunexpected,
    283 		    nfsstats.rpcretries,
    284 		    nfsstats.rpcrequests);
    285 
    286 		printf("Cache Info:\n");
    287 		printf("%10s  %14s  %14s  %14s  %14s\n",
    288 		    "attrcache", "lookupcache", "read", "write", "readlink");
    289 		printf(
    290 	    "%10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%\n",
    291 		    NUMPCT(nfsstats.attrcache_hits,
    292 			nfsstats.attrcache_misses),
    293 		    NUMPCT(nfsstats.lookupcache_hits,
    294 			nfsstats.lookupcache_misses),
    295 		    NUMPCT(nfsstats.biocache_reads - nfsstats.read_bios,
    296 			nfsstats.read_bios),
    297 		    NUMPCT(nfsstats.biocache_writes - nfsstats.write_bios,
    298 			nfsstats.write_bios),
    299 		    NUMPCT(nfsstats.biocache_readlinks - nfsstats.readlink_bios,
    300 			nfsstats.readlink_bios));
    301 		printf("%10s  %14s\n",
    302 		    "readdir", "direofcache");
    303 		printf("%10d %2d%%  %10d %2d%%\n",
    304 		    NUMPCT(nfsstats.biocache_readdirs - nfsstats.readdir_bios,
    305 			nfsstats.readdir_bios),
    306 		    NUMPCT(nfsstats.direofcache_hits,
    307 			nfsstats.direofcache_misses));
    308 	}
    309 
    310 	if (printall || (clientinfo && serverinfo))
    311 		printf("\n");
    312 
    313 	if (printall || serverinfo) {
    314 		total = 0;
    315 		for (i = 0; i < NFS_NPROCS; i++)
    316 			total += nfsstats.srvrpccnt[i];
    317 		printf("Server Info:\n");
    318 		printf("RPC Counts: (%lld call%s)\n", (long long)total,
    319 		    total == 1 ? "" : "s");
    320 
    321 		printf("%10s  %14s  %14s  %14s  %14s\n",
    322 		    "null", "getattr", "setattr", "lookup", "access");
    323 		printf(
    324 	    "%10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%\n",
    325 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_NULL]),
    326 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_GETATTR]),
    327 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_SETATTR]),
    328 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_LOOKUP]),
    329 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_ACCESS]));
    330 		printf("%10s  %14s  %14s  %14s  %14s\n",
    331 		    "readlink", "read", "write", "create", "mkdir");
    332 		printf(
    333 	    "%10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%\n",
    334 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_READLINK]),
    335 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_READ]),
    336 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_WRITE]),
    337 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_CREATE]),
    338 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_MKDIR]));
    339 		printf("%10s  %14s  %14s  %14s  %14s\n",
    340 		    "symlink", "mknod", "remove", "rmdir", "rename");
    341 		printf(
    342 	    "%10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%\n",
    343 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_SYMLINK]),
    344 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_MKNOD]),
    345 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_REMOVE]),
    346 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_RMDIR]),
    347 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_RENAME]));
    348 		printf("%10s  %14s  %14s  %14s  %14s\n",
    349 		    "link", "readdir", "readdirplus", "fsstat", "fsinfo");
    350 		printf(
    351 	    "%10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%\n",
    352 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_LINK]),
    353 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_READDIR]),
    354 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_READDIRPLUS]),
    355 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_FSSTAT]),
    356 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_FSINFO]));
    357 		printf("%10s  %14s  %14s  %14s  %14s\n",
    358 		    "pathconf", "commit", "getlease", "vacated", "evicted");
    359 		printf(
    360 	    "%10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%  %10d %2d%%\n",
    361 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_PATHCONF]),
    362 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_COMMIT]),
    363 		    RPCSTAT(nfsstats.srvrpccnt[NQNFSPROC_GETLEASE]),
    364 		    RPCSTAT(nfsstats.srvrpccnt[NQNFSPROC_VACATED]),
    365 		    RPCSTAT(nfsstats.srvrpccnt[NQNFSPROC_EVICTED]));
    366 		printf("%10s\n", "noop");
    367 		printf("%10d %2d%%\n",
    368 		    RPCSTAT(nfsstats.srvrpccnt[NFSPROC_NOOP]));
    369 
    370 		printf("Server Errors:\n");
    371 		printf("%10s  %14s\n",
    372 		    "RPC errors", "faults");
    373 		printf("%10d  %14d\n",
    374 		    nfsstats.srvrpc_errs,
    375 		    nfsstats.srv_errs);
    376 		printf("Server Cache Stats:\n");
    377 		printf("%10s  %14s  %14s  %14s\n",
    378 		    "inprogress", "idem", "non-idem", "misses");
    379 		printf("%10d  %14d  %14d  %14d\n",
    380 		    nfsstats.srvcache_inproghits,
    381 		    nfsstats.srvcache_idemdonehits,
    382 		    nfsstats.srvcache_nonidemdonehits,
    383 		    nfsstats.srvcache_misses);
    384 		printf("Server Lease Stats:\n");
    385 		printf("%10s  %14s  %14s\n",
    386 		    "leases", "maxleases", "getleases");
    387 		printf("%10d  %14d  %14d\n",
    388 		    nfsstats.srvnqnfs_leases,
    389 		    nfsstats.srvnqnfs_maxleases,
    390 		    nfsstats.srvnqnfs_getleases);
    391 		printf("Server Write Gathering:\n");
    392 		printf("%10s  %14s  %14s\n",
    393 		    "writes", "write RPC", "OPs saved");
    394 		printf("%10d  %14d  %14d %2d%%\n",
    395 		    nfsstats.srvvop_writes,
    396 		    nfsstats.srvrpccnt[NFSPROC_WRITE],
    397 		    NUMPCT(
    398 		      nfsstats.srvrpccnt[NFSPROC_WRITE]-nfsstats.srvvop_writes,
    399 		      nfsstats.srvrpccnt[NFSPROC_WRITE]));
    400 	}
    401 }
    402 
    403 u_char	signalled;			/* set if alarm goes off "early" */
    404 
    405 /*
    406  * Print a running summary of nfs statistics.
    407  * Repeat display every interval seconds, showing statistics
    408  * collected over that interval.  Assumes that interval is non-zero.
    409  * First line printed at top of screen is always cumulative.
    410  */
    411 void
    412 sidewaysintpr(interval)
    413 	u_int interval;
    414 {
    415 	struct nfsstats nfsstats;
    416 	int hdrcnt, oldmask;
    417 	struct stats {
    418 		int client[NSHORTPROC];
    419 		int server[NSHORTPROC];
    420 	} current, last;
    421 
    422 	(void)signal(SIGALRM, catchalarm);
    423 	signalled = 0;
    424 	(void)alarm(interval);
    425 	memset(&last, 0, sizeof(last));
    426 
    427 	for (hdrcnt = 1;;) {
    428 		int i;
    429 
    430 		if (!--hdrcnt) {
    431 			printhdr();
    432 			hdrcnt = 20;
    433 		}
    434 		getstats(&nfsstats);
    435 		memset(&current, 0, sizeof(current));
    436 		for (i = 0; i < NSHORTPROC; i++) {
    437 			int mask = shortprocs[i].mask;
    438 			int idx;
    439 
    440 			while ((idx = ffs(mask)) != 0) {
    441 				idx--;
    442 				mask &= ~(1 << idx);
    443 				current.client[i] += nfsstats.rpccnt[idx];
    444 				current.server[i] += nfsstats.srvrpccnt[idx];
    445 			}
    446 		}
    447 
    448 		if (printall || clientinfo) {
    449 			printf("Client:");
    450 			for (i = 0; i < NSHORTPROC; i++)
    451 				printf(" %7d",
    452 				    current.client[i] - last.client[i]);
    453 			printf("\n");
    454 		}
    455 		if (printall || serverinfo) {
    456 			printf("Server:");
    457 			for (i = 0; i < NSHORTPROC; i++)
    458 				printf(" %7d",
    459 				    current.server[i] - last.server[i]);
    460 			printf("\n");
    461 		}
    462 		memcpy(&last, &current, sizeof(last));
    463 		fflush(stdout);
    464 		oldmask = sigblock(sigmask(SIGALRM));
    465 		if (!signalled)
    466 			sigpause(0);
    467 		sigsetmask(oldmask);
    468 		signalled = 0;
    469 		(void)alarm(interval);
    470 	}
    471 	/*NOTREACHED*/
    472 }
    473 
    474 void
    475 printhdr()
    476 {
    477 	int i;
    478 
    479 	printf("        ");
    480 	for (i = 0; i < NSHORTPROC; i++)
    481 		printf("%7.7s ", shortprocs[i].name);
    482 	printf("\n");
    483 	fflush(stdout);
    484 }
    485 
    486 /*
    487  * Called if an interval expires before sidewaysintpr has completed a loop.
    488  * Sets a flag to not wait for the alarm.
    489  */
    490 void
    491 catchalarm(dummy)
    492 	int dummy;
    493 {
    494 
    495 	signalled = 1;
    496 }
    497 
    498 void
    499 usage()
    500 {
    501 
    502 	(void)fprintf(stderr,
    503 		  "usage: nfsstat [-cs] [-M core] [-N system] [-w interval]\n");
    504 	exit(1);
    505 }
    506