freebsd-src/usr.bin/vmstat/vmstat.c
Jeff Roberson 6f2671750e Remove malloc_type's ks_limit.
Updated the kmemzones logic such that the ks_size bitmap can be used as an
index into it to report the size of the zone used.

Create the kern.malloc sysctl which replaces the kvm mechanism to report
similar data.  This will provide an easy place for statistics aggregation if
malloc_type statistics become per cpu data.

Add some code ifdef'd under MALLOC_PROFILING to facilitate a tool for sizing
the malloc buckets.
2002-04-15 04:05:53 +00:00

822 lines
21 KiB
C

/*
* Copyright (c) 1980, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1980, 1986, 1991, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif
#ifndef lint
static const char sccsid[] = "@(#)vmstat.c 8.1 (Berkeley) 6/6/93";
#endif
#include <sys/param.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/dkstat.h>
#include <sys/uio.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/signal.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#include <vm/vm_param.h>
#include <ctype.h>
#include <devstat.h>
#include <err.h>
#include <errno.h>
#include <kvm.h>
#include <limits.h>
#include <nlist.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <time.h>
#include <unistd.h>
static char da[] = "da";
static struct nlist namelist[] = {
#define X_CPTIME 0
{ "_cp_time" },
#define X_SUM 1
{ "_cnt" },
#define X_BOOTTIME 2
{ "_boottime" },
#define X_HZ 3
{ "_hz" },
#define X_STATHZ 4
{ "_stathz" },
#define X_NCHSTATS 5
{ "_nchstats" },
#define X_INTRNAMES 6
{ "_intrnames" },
#define X_EINTRNAMES 7
{ "_eintrnames" },
#define X_INTRCNT 8
{ "_intrcnt" },
#define X_EINTRCNT 9
{ "_eintrcnt" },
#ifdef notyet
#define X_DEFICIT 10
{ "_deficit" },
#define X_FORKSTAT 11
{ "_forkstat" },
#define X_REC 12
{ "_rectime" },
#define X_PGIN 13
{ "_pgintime" },
#define X_XSTATS 14
{ "_xstats" },
#define X_END 15
#else
#define X_END 10
#endif
{ "" },
};
struct statinfo cur, last;
int num_devices, maxshowdevs;
long generation;
struct device_selection *dev_select;
int num_selected;
struct devstat_match *matches;
int num_matches = 0;
int num_devices_specified, num_selections;
long select_generation;
char **specified_devices;
devstat_select_mode select_mode;
struct vmmeter sum, osum;
int winlines = 20;
int nflag = 0;
kvm_t *kd;
#define FORKSTAT 0x01
#define INTRSTAT 0x02
#define MEMSTAT 0x04
#define SUMSTAT 0x08
#define TIMESTAT 0x10
#define VMSTAT 0x20
#define ZMEMSTAT 0x40
static void cpustats(void);
static void devstats(void);
static void dosysctl(char *);
static void domem(void);
static void dointr(void);
static void dosum(void);
static void dovmstat(u_int, int);
static void dozmem(void);
static void kread(int, void *, size_t);
static void needhdr(int);
static void printhdr(void);
static void usage(void);
static long pct(long, long);
static long getuptime(void);
char **getdrivedata(char **);
int
main(argc, argv)
int argc;
char **argv;
{
int c, todo;
u_int interval;
int reps;
char *memf, *nlistf;
char errbuf[_POSIX2_LINE_MAX];
memf = nlistf = NULL;
interval = reps = todo = 0;
maxshowdevs = 2;
while ((c = getopt(argc, argv, "c:fiM:mN:n:p:stw:z")) != -1) {
switch (c) {
case 'c':
reps = atoi(optarg);
break;
case 'f':
errx(EX_USAGE, "sorry, -f is not (re)implemented yet");
break;
case 'i':
todo |= INTRSTAT;
break;
case 'M':
memf = optarg;
break;
case 'm':
todo |= MEMSTAT;
break;
case 'N':
nlistf = optarg;
break;
case 'n':
nflag = 1;
maxshowdevs = atoi(optarg);
if (maxshowdevs < 0)
errx(1, "number of devices %d is < 0",
maxshowdevs);
break;
case 'p':
if (buildmatch(optarg, &matches, &num_matches) != 0)
errx(1, "%s", devstat_errbuf);
break;
case 's':
todo |= SUMSTAT;
break;
case 't':
#ifdef notyet
todo |= TIMESTAT;
#else
errx(EX_USAGE, "sorry, -t is not (re)implemented yet");
#endif
break;
case 'w':
interval = atoi(optarg);
break;
case 'z':
todo |= ZMEMSTAT;
break;
case '?':
default:
usage();
}
}
argc -= optind;
argv += optind;
if (todo == 0)
todo = VMSTAT;
/*
* Discard setgid privileges if not the running kernel so that bad
* guys can't print interesting stuff from kernel memory.
*/
if (nlistf != NULL || memf != NULL)
setgid(getgid());
kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf);
if (kd == 0)
errx(1, "kvm_openfiles: %s", errbuf);
setgid(getgid());
if ((c = kvm_nlist(kd, namelist)) != 0) {
if (c > 0) {
warnx("undefined symbols:");
for (c = 0;
c < (int)(sizeof(namelist)/sizeof(namelist[0]));
c++)
if (namelist[c].n_type == 0)
(void)fprintf(stderr, " %s",
namelist[c].n_name);
(void)fputc('\n', stderr);
} else
warnx("kvm_nlist: %s", kvm_geterr(kd));
exit(1);
}
if (todo & VMSTAT) {
struct winsize winsize;
/*
* Make sure that the userland devstat version matches the
* kernel devstat version. If not, exit and print a
* message informing the user of his mistake.
*/
if (checkversion() < 0)
errx(1, "%s", devstat_errbuf);
argv = getdrivedata(argv);
winsize.ws_row = 0;
(void) ioctl(STDOUT_FILENO, TIOCGWINSZ, (char *)&winsize);
if (winsize.ws_row > 0)
winlines = winsize.ws_row;
}
#define BACKWARD_COMPATIBILITY
#ifdef BACKWARD_COMPATIBILITY
if (*argv) {
interval = atoi(*argv);
if (*++argv)
reps = atoi(*argv);
}
#endif
if (interval) {
if (!reps)
reps = -1;
} else if (reps)
interval = 1;
#ifdef notyet
if (todo & FORKSTAT)
doforkst();
#endif
if (todo & MEMSTAT)
domem();
if (todo & ZMEMSTAT)
dozmem();
if (todo & SUMSTAT)
dosum();
#ifdef notyet
if (todo & TIMESTAT)
dotimes();
#endif
if (todo & INTRSTAT)
dointr();
if (todo & VMSTAT)
dovmstat(interval, reps);
exit(0);
}
char **
getdrivedata(argv)
char **argv;
{
if ((num_devices = getnumdevs()) < 0)
errx(1, "%s", devstat_errbuf);
cur.dinfo = (struct devinfo *)malloc(sizeof(struct devinfo));
last.dinfo = (struct devinfo *)malloc(sizeof(struct devinfo));
bzero(cur.dinfo, sizeof(struct devinfo));
bzero(last.dinfo, sizeof(struct devinfo));
if (getdevs(&cur) == -1)
errx(1, "%s", devstat_errbuf);
num_devices = cur.dinfo->numdevs;
generation = cur.dinfo->generation;
specified_devices = (char **)malloc(sizeof(char *));
for (num_devices_specified = 0; *argv; ++argv) {
if (isdigit(**argv))
break;
num_devices_specified++;
specified_devices = (char **)realloc(specified_devices,
sizeof(char *) *
num_devices_specified);
specified_devices[num_devices_specified - 1] = *argv;
}
dev_select = NULL;
if (nflag == 0 && maxshowdevs < num_devices_specified)
maxshowdevs = num_devices_specified;
/*
* People are generally only interested in disk statistics when
* they're running vmstat. So, that's what we're going to give
* them if they don't specify anything by default. We'll also give
* them any other random devices in the system so that we get to
* maxshowdevs devices, if that many devices exist. If the user
* specifies devices on the command line, either through a pattern
* match or by naming them explicitly, we will give the user only
* those devices.
*/
if ((num_devices_specified == 0) && (num_matches == 0)) {
if (buildmatch(da, &matches, &num_matches) != 0)
errx(1, "%s", devstat_errbuf);
select_mode = DS_SELECT_ADD;
} else
select_mode = DS_SELECT_ONLY;
/*
* At this point, selectdevs will almost surely indicate that the
* device list has changed, so we don't look for return values of 0
* or 1. If we get back -1, though, there is an error.
*/
if (selectdevs(&dev_select, &num_selected, &num_selections,
&select_generation, generation, cur.dinfo->devices,
num_devices, matches, num_matches, specified_devices,
num_devices_specified, select_mode,
maxshowdevs, 0) == -1)
errx(1, "%s", devstat_errbuf);
return(argv);
}
long
getuptime()
{
static time_t now, boottime;
time_t uptime;
if (boottime == 0)
kread(X_BOOTTIME, &boottime, sizeof(boottime));
(void)time(&now);
uptime = now - boottime;
if (uptime <= 0 || uptime > 60*60*24*365*10)
errx(1, "time makes no sense; namelist must be wrong");
return(uptime);
}
int hz, hdrcnt;
void
dovmstat(interval, reps)
u_int interval;
int reps;
{
struct vmtotal total;
time_t uptime, halfuptime;
struct devinfo *tmp_dinfo;
int mib[2];
size_t size;
uptime = getuptime();
halfuptime = uptime / 2;
(void)signal(SIGCONT, needhdr);
if (namelist[X_STATHZ].n_type != 0 && namelist[X_STATHZ].n_value != 0)
kread(X_STATHZ, &hz, sizeof(hz));
if (!hz)
kread(X_HZ, &hz, sizeof(hz));
for (hdrcnt = 1;;) {
if (!--hdrcnt)
printhdr();
kread(X_CPTIME, cur.cp_time, sizeof(cur.cp_time));
tmp_dinfo = last.dinfo;
last.dinfo = cur.dinfo;
cur.dinfo = tmp_dinfo;
last.busy_time = cur.busy_time;
/*
* Here what we want to do is refresh our device stats.
* getdevs() returns 1 when the device list has changed.
* If the device list has changed, we want to go through
* the selection process again, in case a device that we
* were previously displaying has gone away.
*/
switch (getdevs(&cur)) {
case -1:
errx(1, "%s", devstat_errbuf);
break;
case 1: {
int retval;
num_devices = cur.dinfo->numdevs;
generation = cur.dinfo->generation;
retval = selectdevs(&dev_select, &num_selected,
&num_selections, &select_generation,
generation, cur.dinfo->devices,
num_devices, matches, num_matches,
specified_devices,
num_devices_specified, select_mode,
maxshowdevs, 0);
switch (retval) {
case -1:
errx(1, "%s", devstat_errbuf);
break;
case 1:
printhdr();
break;
default:
break;
}
}
default:
break;
}
kread(X_SUM, &sum, sizeof(sum));
size = sizeof(total);
mib[0] = CTL_VM;
mib[1] = VM_METER;
if (sysctl(mib, 2, &total, &size, NULL, 0) < 0) {
(void)printf("Can't get kerninfo: %s\n",
strerror(errno));
bzero(&total, sizeof(total));
}
(void)printf("%2d %1d %1d",
total.t_rq - 1, total.t_dw + total.t_pw, total.t_sw);
#define vmstat_pgtok(a) ((a) * sum.v_page_size >> 10)
#define rate(x) (((x) + halfuptime) / uptime) /* round */
(void)printf(" %7ld %6ld ", (long)vmstat_pgtok(total.t_avm),
(long)vmstat_pgtok(total.t_free));
(void)printf("%4lu ",
(u_long)rate(sum.v_vm_faults - osum.v_vm_faults));
(void)printf("%3lu ",
(u_long)rate(sum.v_reactivated - osum.v_reactivated));
(void)printf("%3lu ",
(u_long)rate(sum.v_swapin + sum.v_vnodein -
(osum.v_swapin + osum.v_vnodein)));
(void)printf("%3lu ",
(u_long)rate(sum.v_swapout + sum.v_vnodeout -
(osum.v_swapout + osum.v_vnodeout)));
(void)printf("%3lu ",
(u_long)rate(sum.v_tfree - osum.v_tfree));
(void)printf("%3lu ",
(u_long)rate(sum.v_pdpages - osum.v_pdpages));
devstats();
(void)printf("%4lu %4lu %3lu ",
(u_long)rate(sum.v_intr - osum.v_intr),
(u_long)rate(sum.v_syscall - osum.v_syscall),
(u_long)rate(sum.v_swtch - osum.v_swtch));
cpustats();
(void)printf("\n");
(void)fflush(stdout);
if (reps >= 0 && --reps <= 0)
break;
osum = sum;
uptime = interval;
/*
* We round upward to avoid losing low-frequency events
* (i.e., >= 1 per interval but < 1 per second).
*/
if (interval != 1)
halfuptime = (uptime + 1) / 2;
else
halfuptime = 0;
(void)sleep(interval);
}
}
void
printhdr()
{
int i, num_shown;
num_shown = (num_selected < maxshowdevs) ? num_selected : maxshowdevs;
(void)printf(" procs memory page%*s", 19, "");
if (num_shown > 1)
(void)printf(" disks %*s", num_shown * 4 - 7, "");
else if (num_shown == 1)
(void)printf("disk");
(void)printf(" faults cpu\n");
(void)printf(" r b w avm fre flt re pi po fr sr ");
for (i = 0; i < num_devices; i++)
if ((dev_select[i].selected)
&& (dev_select[i].selected <= maxshowdevs))
(void)printf("%c%c%d ", dev_select[i].device_name[0],
dev_select[i].device_name[1],
dev_select[i].unit_number);
(void)printf(" in sy cs us sy id\n");
hdrcnt = winlines - 2;
}
/*
* Force a header to be prepended to the next output.
*/
void
needhdr(dummy)
int dummy __unused;
{
hdrcnt = 1;
}
#ifdef notyet
void
dotimes()
{
u_int pgintime, rectime;
kread(X_REC, &rectime, sizeof(rectime));
kread(X_PGIN, &pgintime, sizeof(pgintime));
kread(X_SUM, &sum, sizeof(sum));
(void)printf("%u reclaims, %u total time (usec)\n",
sum.v_pgrec, rectime);
(void)printf("average: %u usec / reclaim\n", rectime / sum.v_pgrec);
(void)printf("\n");
(void)printf("%u page ins, %u total time (msec)\n",
sum.v_pgin, pgintime / 10);
(void)printf("average: %8.1f msec / page in\n",
pgintime / (sum.v_pgin * 10.0));
}
#endif
long
pct(top, bot)
long top, bot;
{
long ans;
if (bot == 0)
return(0);
ans = (quad_t)top * 100 / bot;
return (ans);
}
#define PCT(top, bot) pct((long)(top), (long)(bot))
void
dosum()
{
struct nchstats lnchstats;
long nchtotal;
kread(X_SUM, &sum, sizeof(sum));
(void)printf("%9u cpu context switches\n", sum.v_swtch);
(void)printf("%9u device interrupts\n", sum.v_intr);
(void)printf("%9u software interrupts\n", sum.v_soft);
(void)printf("%9u traps\n", sum.v_trap);
(void)printf("%9u system calls\n", sum.v_syscall);
(void)printf("%9u kernel threads created\n", sum.v_kthreads);
(void)printf("%9u fork() calls\n", sum.v_forks);
(void)printf("%9u vfork() calls\n", sum.v_vforks);
(void)printf("%9u rfork() calls\n", sum.v_rforks);
(void)printf("%9u swap pager pageins\n", sum.v_swapin);
(void)printf("%9u swap pager pages paged in\n", sum.v_swappgsin);
(void)printf("%9u swap pager pageouts\n", sum.v_swapout);
(void)printf("%9u swap pager pages paged out\n", sum.v_swappgsout);
(void)printf("%9u vnode pager pageins\n", sum.v_vnodein);
(void)printf("%9u vnode pager pages paged in\n", sum.v_vnodepgsin);
(void)printf("%9u vnode pager pageouts\n", sum.v_vnodeout);
(void)printf("%9u vnode pager pages paged out\n", sum.v_vnodepgsout);
(void)printf("%9u page daemon wakeups\n", sum.v_pdwakeups);
(void)printf("%9u pages examined by the page daemon\n", sum.v_pdpages);
(void)printf("%9u pages reactivated\n", sum.v_reactivated);
(void)printf("%9u copy-on-write faults\n", sum.v_cow_faults);
(void)printf("%9u copy-on-write optimized faults\n", sum.v_cow_optim);
(void)printf("%9u zero fill pages zeroed\n", sum.v_zfod);
(void)printf("%9u zero fill pages prezeroed\n", sum.v_ozfod);
(void)printf("%9u intransit blocking page faults\n", sum.v_intrans);
(void)printf("%9u total VM faults taken\n", sum.v_vm_faults);
(void)printf("%9u pages affected by kernel thread creation\n", sum.v_kthreadpages);
(void)printf("%9u pages affected by fork()\n", sum.v_forkpages);
(void)printf("%9u pages affected by vfork()\n", sum.v_vforkpages);
(void)printf("%9u pages affected by rfork()\n", sum.v_rforkpages);
(void)printf("%9u pages freed\n", sum.v_tfree);
(void)printf("%9u pages freed by daemon\n", sum.v_dfree);
(void)printf("%9u pages freed by exiting processes\n", sum.v_pfree);
(void)printf("%9u pages active\n", sum.v_active_count);
(void)printf("%9u pages inactive\n", sum.v_inactive_count);
(void)printf("%9u pages in VM cache\n", sum.v_cache_count);
(void)printf("%9u pages wired down\n", sum.v_wire_count);
(void)printf("%9u pages free\n", sum.v_free_count);
(void)printf("%9u bytes per page\n", sum.v_page_size);
kread(X_NCHSTATS, &lnchstats, sizeof(lnchstats));
nchtotal = lnchstats.ncs_goodhits + lnchstats.ncs_neghits +
lnchstats.ncs_badhits + lnchstats.ncs_falsehits +
lnchstats.ncs_miss + lnchstats.ncs_long;
(void)printf("%9ld total name lookups\n", nchtotal);
(void)printf(
"%9s cache hits (%ld%% pos + %ld%% neg) system %ld%% per-directory\n",
"", PCT(lnchstats.ncs_goodhits, nchtotal),
PCT(lnchstats.ncs_neghits, nchtotal),
PCT(lnchstats.ncs_pass2, nchtotal));
(void)printf("%9s deletions %ld%%, falsehits %ld%%, toolong %ld%%\n", "",
PCT(lnchstats.ncs_badhits, nchtotal),
PCT(lnchstats.ncs_falsehits, nchtotal),
PCT(lnchstats.ncs_long, nchtotal));
}
#ifdef notyet
void
doforkst()
{
struct forkstat fks;
kread(X_FORKSTAT, &fks, sizeof(struct forkstat));
(void)printf("%d forks, %d pages, average %.2f\n",
fks.cntfork, fks.sizfork, (double)fks.sizfork / fks.cntfork);
(void)printf("%d vforks, %d pages, average %.2f\n",
fks.cntvfork, fks.sizvfork, (double)fks.sizvfork / fks.cntvfork);
}
#endif
static void
devstats()
{
int dn, state;
long double transfers_per_second;
long double busy_seconds;
long tmp;
for (state = 0; state < CPUSTATES; ++state) {
tmp = cur.cp_time[state];
cur.cp_time[state] -= last.cp_time[state];
last.cp_time[state] = tmp;
}
busy_seconds = compute_etime(cur.busy_time, last.busy_time);
for (dn = 0; dn < num_devices; dn++) {
int di;
if ((dev_select[dn].selected == 0)
|| (dev_select[dn].selected > maxshowdevs))
continue;
di = dev_select[dn].position;
if (devstat_compute_statistics(&cur.dinfo->devices[di],
&last.dinfo->devices[di], busy_seconds,
DSM_TRANSFERS_PER_SECOND, &transfers_per_second,
DSM_NONE) != 0)
errx(1, "%s", devstat_errbuf);
(void)printf("%3.0Lf ", transfers_per_second);
}
}
void
cpustats()
{
int state;
double lpct, total;
total = 0;
for (state = 0; state < CPUSTATES; ++state)
total += cur.cp_time[state];
if (total)
lpct = 100.0 / total;
else
lpct = 0.0;
(void)printf("%2.0f ", (cur.cp_time[CP_USER] +
cur.cp_time[CP_NICE]) * lpct);
(void)printf("%2.0f ", (cur.cp_time[CP_SYS] +
cur.cp_time[CP_INTR]) * lpct);
(void)printf("%2.0f", cur.cp_time[CP_IDLE] * lpct);
}
void
dointr()
{
u_long *intrcnt, uptime;
u_int64_t inttotal;
int nintr, inamlen;
char *intrname;
uptime = getuptime();
nintr = namelist[X_EINTRCNT].n_value - namelist[X_INTRCNT].n_value;
inamlen =
namelist[X_EINTRNAMES].n_value - namelist[X_INTRNAMES].n_value;
intrcnt = malloc((size_t)nintr);
intrname = malloc((size_t)inamlen);
if (intrcnt == NULL || intrname == NULL)
errx(1, "malloc");
kread(X_INTRCNT, intrcnt, (size_t)nintr);
kread(X_INTRNAMES, intrname, (size_t)inamlen);
(void)printf("interrupt total rate\n");
inttotal = 0;
nintr /= sizeof(long);
while (--nintr >= 0) {
if (*intrcnt)
(void)printf("%-12s %20lu %10lu\n", intrname,
*intrcnt, *intrcnt / uptime);
intrname += strlen(intrname) + 1;
inttotal += *intrcnt++;
}
(void)printf("Total %20llu %10llu\n", inttotal,
inttotal / (u_int64_t) uptime);
}
void
domem(void)
{
dosysctl("kern.malloc");
}
void
dozmem(void)
{
dosysctl("vm.zone");
}
void
dosysctl(char *name)
{
char *buf;
size_t bufsize;
buf = NULL;
bufsize = 1024;
for (;;) {
if ((buf = realloc(buf, bufsize)) == NULL)
err(1, "realloc()");
if (sysctlbyname(name, buf, &bufsize, 0, NULL) == 0)
break;
if (errno != ENOMEM)
err(1, "sysctl()");
bufsize *= 2;
}
buf[bufsize] = '\0'; /* play it safe */
(void)printf("%s\n\n", buf);
free(buf);
}
/*
* kread reads something from the kernel, given its nlist index.
*/
void
kread(nlx, addr, size)
int nlx;
void *addr;
size_t size;
{
char *sym;
if (namelist[nlx].n_type == 0 || namelist[nlx].n_value == 0) {
sym = namelist[nlx].n_name;
if (*sym == '_')
++sym;
errx(1, "symbol %s not defined", sym);
}
if (kvm_read(kd, namelist[nlx].n_value, addr, size) != (int)size) {
sym = namelist[nlx].n_name;
if (*sym == '_')
++sym;
errx(1, "%s: %s", sym, kvm_geterr(kd));
}
}
void
usage()
{
(void)fprintf(stderr, "%s%s",
"usage: vmstat [-imsz] [-c count] [-M core] [-N system] [-w wait]\n",
" [-n devs] [disks]\n");
exit(1);
}