source: trunk/third/top/machine/m_netbsd132.c @ 16185

/*
 * top - a top users display for Unix
 *
 * SYNOPSIS:  For a NetBSD-1.3.2 (4.4BSD) system
 *          Note process resident sizes could be wrong, but ps shows
 *          zero for them too..
 *
 * DESCRIPTION:
 * Originally written for BSD4.4 system by Christos Zoulas.
 * Based on the FreeBSD 2.0 version by Steven Wallace && Wolfram Schneider
 * NetBSD-1.0 port by Arne Helme
 * NetBSD-1.3.2(sparc) port by moto kawasaki
 * .
 * This is the machine-dependent module for NetBSD-1.3.2
 * Works for:
 *    NetBSD-1.3.2
 *
 * LIBS: -lkvm
 *
 * CFLAGS: -DHAVE_GETOPT -D__NetBSD132__
 *
 * AUTHOR:  Christos Zoulas <christos@ee.cornell.edu>
 *          Steven Wallace  <swallace@freebsd.org>
 *          Wolfram Schneider <wosch@cs.tu-berlin.de>
 *        Arne Helme <arne@acm.org>
 *          moto kawasaki <kawasaki@sphere.ad.jp>
 *
 * $Id: m_netbsd132.c,v 1.1.1.1 2001-05-08 21:47:58 ghudson Exp $
 */



#define LASTPID      /**/  /* use last pid, compiler depended */
/* #define LASTPID_FIXED /**/
#define VM_REAL      /**/  /* use the same values as vmstat -s */
#define USE_SWAP    /**/  /* use swap usage (pstat -s),
                              need to much cpu time */
#ifdef __NetBSD132__
# undef USE_SWAP
#endif                        /* moto kawasaki */
/* #define DEBUG 1      /**/

#include <sys/types.h>
#include <sys/signal.h>
#include <sys/param.h>

#include "os.h"
#include <stdio.h>
#include <nlist.h>
#include <math.h>
#include <kvm.h>
#include <sys/errno.h>
#include <sys/sysctl.h>
#include <sys/dir.h>
#include <sys/dkstat.h>
#include <sys/file.h>
#include <sys/time.h>

#ifdef USE_SWAP
#include <stdlib.h>
#include <sys/map.h>
#include <sys/conf.h>
#endif

static int check_nlist __P((struct nlist *));
static int getkval __P((unsigned long, int *, int, char *));
extern char* printable __P((char *));

#include "top.h"
#include "machine.h"


/* get_process_info passes back a handle.  This is what it looks like: */

struct handle
{
    struct kinfo_proc **next_proc;    /* points to next valid proc pointer

    int remaining;            /* number of pointers remaining */
};

/* declarations for load_avg */
#include "loadavg.h"

#define PP(pp, field) ((pp)->kp_proc . field)
#define EP(pp, field) ((pp)->kp_eproc . field)
#define VP(pp, field) ((pp)->kp_eproc.e_vm . field)

/* define what weighted cpu is.  */
#define weighted_cpu(pct, pp) (PP((pp), p_swtime) == 0 ? 0.0 : \
                       ((pct) / (1.0 - exp(PP((pp), p_swtime) * logcpu))))

/* what we consider to be process size: */
#define PROCSIZE(pp) (VP((pp), vm_tsize) + VP((pp), vm_dsize) + VP((pp),
_ssize))

/* definitions for indices in the nlist array */


static struct nlist nlst[] = {
#define X_CCPU                0
    { "_ccpu" },              /* 0 */
#define X_CP_TIME     1
    { "_cp_time" },           /* 1 */
#define X_HZ          2
    { "_hz" },                        /* 2 */
#define X_STATHZ      3
    { "_stathz" },            /* 3 */
#define X_AVENRUN     4
    { "_averunnable" },               /* 4 */

#ifdef USE_SWAP
#define VM_SWAPMAP    5
      { "_swapmap" }, /* list of free swap areas */
#define VM_NSWAPMAP   6
      { "_nswapmap" },/* size of the swap map */
#define VM_SWDEVT     7
      { "_swdevt" },  /* list of swap devices and sizes */
#define VM_NSWAP      8
      { "_nswap" },   /* size of largest swap device */
#define VM_NSWDEV     9
      { "_nswdev" },  /* number of swap devices */
#define VM_DMMAX      10
      { "_dmmax" },   /* maximum size of a swap block */
#define VM_NISWAP     11
      { "_niswap" },
#define VM_NISWDEV    12
      { "_niswdev" },
#endif /* USE_SWAP */

#ifdef VM_REAL
#ifdef USE_SWAP
#define X_CNT           13
#else
#define X_CNT           5
#endif
    { "_cnt" },                       /* struct vmmeter cnt */
#endif

#ifdef LASTPID
#if (defined USE_SWAP && defined VM_REAL)
#define X_LASTPID     14
#elif (defined VM_REAL)
#define X_LASTPID     6
#else
#define X_LASTPID       5
#endif
#ifdef LASTPID_FIXED
    { "_nextpid" },
#else
    { "_nextpid.178" },               /* lastpid, compiler depended
                               * should be changed
                               * in /sys/kern/kern_fork.c */
#endif
#endif

    { 0 }
};

/*
 *  These definitions control the format of the per-process area
 */

static char header[] =
  "  PID X        PRI NICE   SIZE   RES STATE   TIME   WCPU    CPU COMMAND";
/* 0123456   -- field to fill in starts at header+6 */
#define UNAME_START 6

#define Proc_format \
      "%5d %-8.8s %3d %4d%7s %5s %-5s%7s %5.2f%% %5.2f%% %.14s"


/* process state names for the "STATE" column of the display */
/* the extra nulls in the string "run" are for adding a slash and
   the processor number when needed */

char *state_abbrev[] =
{
    "", "start", "run\0\0\0", "sleep", "stop", "zomb", "WAIT"
};


static kvm_t *kd;

/* values that we stash away in _init and use in later routines */

static double logcpu;

/* these are retrieved from the kernel in _init */

static          long hz;
static load_avg  ccpu;

/* these are offsets obtained via nlist and used in the get_ functions */

static unsigned long cp_time_offset;
static unsigned long avenrun_offset;
#ifdef LASTPID
static unsigned long lastpid_offset;
static long lastpid;
#endif
#ifdef VM_REAL
static unsigned long cnt_offset;
static long cnt;
#endif
/* these are for calculating cpu state percentages */

static long cp_time[CPUSTATES];
static long cp_old[CPUSTATES];
static long cp_diff[CPUSTATES];

/* these are for detailing the process states */

int process_states[7];
char *procstatenames[] = {
    "", " starting, ", " running, ", " sleeping, ", " stopped, ",
    " zombie, ", " ABANDONED, ",
    NULL
};

/* these are for detailing the cpu states */

int cpu_states[CPUSTATES];
char *cpustatenames[] = {
    "user", "nice", "system", "interrupt", "idle", NULL
};

/* these are for detailing the memory statistics */

int memory_stats[8];
char *memorynames[] = {
#ifndef VM_REAL
    "Real: ", "K/", "K ", "Virt: ", "K/",
    "K ", "Free: ", "K", NULL
#else
#if 0
    "K Act ", "K Inact ", "K Wired ", "K Free ", "% Swap, ",
    "K/", "K SWIO",
#else
    "K Act ", "K Inact ", "K Wired ", "K Free ", "% Swap, ",
    "Kin ", "Kout",
#endif
    NULL
#endif
};

/* these are for keeping track of the proc array */

static int nproc;
static int onproc = -1;
static int pref_len;
static struct kinfo_proc *pbase;
static struct kinfo_proc **pref;

/* these are for getting the memory statistics */

static int pageshift;         /* log base 2 of the pagesize */

/* define pagetok in terms of pageshift */

#define pagetok(size) ((size) << pageshift)

/* useful externals */
long percentages();

int
machine_init(statics)

struct statics *statics;

{
    register int i = 0;
    register int pagesize;

    if ((kd = kvm_open(NULL, NULL, NULL, O_RDONLY, "kvm_open")) == NULL)
      return -1;


    /* get the list of symbols we want to access in the kernel */
    (void) kvm_nlist(kd, nlst);
    if (nlst[0].n_type == 0)
    {
      fprintf(stderr, "top: nlist failed\n");
      return(-1);
    }

    /* make sure they were all found */
    if (i > 0 && check_nlist(nlst) > 0)
    {
      return(-1);
    }

    /* get the symbol values out of kmem */
    (void) getkval(nlst[X_STATHZ].n_value, (int *)(&hz), sizeof(hz), "!");
    if (!hz) {
      (void) getkval(nlst[X_HZ].n_value, (int *)(&hz), sizeof(hz),
                     nlst[X_HZ].n_name);
    }


#if (defined DEBUG)
    fprintf(stderr, "Hertz: %d\n", hz);
#endif

    (void) getkval(nlst[X_CCPU].n_value,   (int *)(&ccpu),    sizeof(ccpu),
          nlst[X_CCPU].n_name);

    /* stash away certain offsets for later use */
    cp_time_offset = nlst[X_CP_TIME].n_value;
    avenrun_offset = nlst[X_AVENRUN].n_value;
#ifdef LASTPID
    lastpid_offset =  nlst[X_LASTPID].n_value;
#endif
#ifdef VM_REAL
    cnt_offset = nlst[X_CNT].n_value;
#endif

    /* this is used in calculating WCPU -- calculate it ahead of time */
    logcpu = log(loaddouble(ccpu));

    pbase = NULL;
    pref = NULL;
    nproc = 0;
    onproc = -1;
    /* get the page size with "getpagesize" and calculate pageshift from it

    pagesize = getpagesize();
    pageshift = 0;
    while (pagesize > 1)
    {
      pageshift++;
      pagesize >>= 1;
    }

    /* we only need the amount of log(2)1024 for our conversion */
    pageshift -= LOG1024;

    /* fill in the statics information */
    statics->procstate_names = procstatenames;
    statics->cpustate_names = cpustatenames;
    statics->memory_names = memorynames;

    /* all done! */
    return(0);
}

char *format_header(uname_field)

register char *uname_field;

{
    register char *ptr;

    ptr = header + UNAME_START;
    while (*uname_field != '\0')
    {
      *ptr++ = *uname_field++;
    }

    return(header);
}

static int swappgsin = -1;
static int swappgsout = -1;
extern struct timeval timeout;

void
get_system_info(si)

struct system_info *si;

{
    long total;
    load_avg avenrun[3];

    /* get the cp_time array */
    (void) getkval(cp_time_offset, (int *)cp_time, sizeof(cp_time),
                 nlst[X_CP_TIME].n_name);
    (void) getkval(avenrun_offset, (int *)avenrun, sizeof(avenrun),
                 nlst[X_AVENRUN].n_name);

#ifdef LASTPID
    (void) getkval(lastpid_offset, (int *)(&lastpid), sizeof(lastpid),
                 "!");
#endif

    /* convert load averages to doubles */
    {
      register int i;
      register double *infoloadp;
      load_avg *avenrunp;

#ifdef notyet
      struct loadavg sysload;
      int size;
      getkerninfo(KINFO_LOADAVG, &sysload, &size, 0);
#endif

      infoloadp = si->load_avg;
      avenrunp = avenrun;
      for (i = 0; i < 3; i++)
      {
#ifdef notyet
          *infoloadp++ = ((double) sysload.ldavg[i]) / sysload.fscale;
#endif
          *infoloadp++ = loaddouble(*avenrunp++);
      }
    }

    /* convert cp_time counts to percentages */
    total = percentages(CPUSTATES, cpu_states, cp_time, cp_old, cp_diff);

    /* sum memory statistics */
    {

#ifndef VM_REAL
      struct vmtotal total;
      int size = sizeof(total);
      static int mib[] = { CTL_VM, VM_METER };

      /* get total -- systemwide main memory usage structure */
      if (sysctl(mib, 2, &total, &size, NULL, 0) < 0) {
          (void) fprintf(stderr, "top: sysctl failed: %s\n",
rerror(errno));
          bzero(&total, sizeof(total));
      }
      /* convert memory stats to Kbytes */
      memory_stats[0] = -1;
      memory_stats[1] = pagetok(total.t_arm);
      memory_stats[2] = pagetok(total.t_rm);
      memory_stats[3] = -1;
      memory_stats[4] = pagetok(total.t_avm);
      memory_stats[5] = pagetok(total.t_vm);
      memory_stats[6] = -1;
      memory_stats[7] = pagetok(total.t_free);
    }
#else
      struct vmmeter sum;
      static unsigned int swap_delay = 0;

        (void) getkval(cnt_offset, (int *)(&sum), sizeof(sum),
                 "_cnt");

      /* convert memory stats to Kbytes */
      memory_stats[0] = pagetok(sum.v_active_count);
      memory_stats[1] = pagetok(sum.v_inactive_count);
      memory_stats[2] = pagetok(sum.v_wire_count);
      memory_stats[3] = pagetok(sum.v_free_count);

        if (swappgsin < 0) {
          memory_stats[5] = 0;
          memory_stats[6] = 0;
      } else {
          memory_stats[5] = pagetok(((sum.v_pswpin - swappgsin)));
          memory_stats[6] = pagetok(((sum.v_pswpout - swappgsout)));
      }
        swappgsin = sum.v_pswpin;
      swappgsout = sum.v_pswpout;

#ifdef USE_SWAP
        if ((memory_stats[5] > 0 || memory_stats[6]) > 0 || swap_delay == 0)

          memory_stats[4] = swapmode();
      }
        /* swap_delay++; XXX Arne */
#else
        memory_stats[4] = 0;
#endif


      memory_stats[7] = -1;
    }
#endif
    /* set arrays and strings */
    si->cpustates = cpu_states;
    si->memory = memory_stats;
#ifdef LASTPID
    if(lastpid > 0) {
      si->last_pid = lastpid;
    } else {
      si->last_pid = -1;
    }
#else
    si->last_pid = -1;
#endif

}

static struct handle handle;

caddr_t get_process_info(si, sel, compare)

struct system_info *si;
struct process_select *sel;
int (*compare)();

{
    register int i;
    register int total_procs;
    register int active_procs;
    register struct kinfo_proc **prefp;
    register struct kinfo_proc *pp;

    /* these are copied out of sel for speed */
    int show_idle;
    int show_system;
    int show_uid;
    int show_command;


    pbase = kvm_getprocs(kd, KERN_PROC_ALL, 0, &nproc);
    if (nproc > onproc)
      pref = (struct kinfo_proc **) realloc(pref, sizeof(struct kinfo_proc

              * (onproc = nproc));
    if (pref == NULL || pbase == NULL) {
      (void) fprintf(stderr, "top: Out of memory.\n");
      quit(23);
    }
    /* get a pointer to the states summary array */
    si->procstates = process_states;

    /* set up flags which define what we are going to select */
    show_idle = sel->idle;
    show_system = sel->system;
    show_uid = sel->uid != -1;
    show_command = sel->command != NULL;

    /* count up process states and get pointers to interesting procs */
    total_procs = 0;
    active_procs = 0;
    memset((char *)process_states, 0, sizeof(process_states));
    prefp = pref;
    for (pp = pbase, i = 0; i < nproc; pp++, i++)
    {
      /*
       *  Place pointers to each valid proc structure in pref[].
       *  Process slots that are actually in use have a non-zero
       *  status field.  Processes with P_SYSTEM set are system
       *  processes---these get ignored unless show_sysprocs is set.
       */
      if (PP(pp, p_stat) != 0 &&
          (show_system || ((PP(pp, p_flag) & P_SYSTEM) == 0)))
      {
          total_procs++;
          process_states[(unsigned char) PP(pp, p_stat)]++;
          if ((PP(pp, p_stat) != SZOMB) &&
              (show_idle || (PP(pp, p_pctcpu) != 0) ||
               (PP(pp, p_stat) == SRUN)) &&
              (!show_uid || EP(pp, e_pcred.p_ruid) == (uid_t)sel->uid))
          {
              *prefp++ = pp;
              active_procs++;
          }
      }
    }

    /* if requested, sort the "interesting" processes */
    if (compare != NULL)
    {
      qsort((char *)pref, active_procs, sizeof(struct kinfo_proc *),
mpare);
    }

    /* remember active and total counts */
    si->p_total = total_procs;
    si->p_active = pref_len = active_procs;

    /* pass back a handle */
    handle.next_proc = pref;
    handle.remaining = active_procs;
    return((caddr_t)&handle);
}

char fmt[128];                /* static area where result is built */

char *format_next_process(handle, get_userid)

caddr_t handle;
char *(*get_userid)();

{
    register struct kinfo_proc *pp;
    register long cputime;
    register double pct;
    struct handle *hp;

    /* find and remember the next proc structure */
    hp = (struct handle *)handle;
    pp = *(hp->next_proc++);
    hp->remaining--;


    /* get the process's user struct and set cputime */
    if ((PP(pp, p_flag) & P_INMEM) == 0) {
      /*
       * Print swapped processes as <pname>
       */
      char *comm = PP(pp, p_comm);
#define COMSIZ sizeof(PP(pp, p_comm))
      char buf[COMSIZ];
      (void) strncpy(buf, comm, COMSIZ);
      comm[0] = '<';
      (void) strncpy(&comm[1], buf, COMSIZ - 2);
      comm[COMSIZ - 2] = '\0';
      (void) strncat(comm, ">", COMSIZ - 1);
      comm[COMSIZ - 1] = '\0';
    }

#if 0
    /* This does not produce the correct results */
    cputime = PP(pp, p_uticks) + PP(pp, p_sticks) + PP(pp, p_iticks);
#endif
    cputime = PP(pp, p_rtime).tv_sec; /* This does not count interrupts */

    /* calculate the base for cpu percentages */
    pct = pctdouble(PP(pp, p_pctcpu));

    /* format this entry */
    sprintf(fmt,
          Proc_format,
          PP(pp, p_pid),
          (*get_userid)(EP(pp, e_pcred.p_ruid)),
          PP(pp, p_priority) - PZERO,
          PP(pp, p_nice) - NZERO,
          format_k(pagetok(PROCSIZE(pp))),
          format_k(pagetok(VP(pp, vm_rssize))),
          state_abbrev[(unsigned char) PP(pp, p_stat)],
          format_time(cputime),
          10000.0 * weighted_cpu(pct, pp) / hz,
          10000.0 * pct / hz,
          printable(PP(pp, p_comm)));

    /* return the result */
    return(fmt);
}


/*
 * check_nlist(nlst) - checks the nlist to see if any symbols were not
 *            found.  For every symbol that was not found, a one-line
 *            message is printed to stderr.  The routine returns the
 *            number of symbols NOT found.
 */

static int check_nlist(nlst)

register struct nlist *nlst;

{
    register int i;

    /* check to see if we got ALL the symbols we requested */
    /* this will write one line to stderr for every symbol not found */

    i = 0;
    while (nlst->n_name != NULL)
    {
      if (nlst->n_type == 0)
      {
          /* this one wasn't found */
          (void) fprintf(stderr, "kernel: no symbol named `%s'\n",
                         nlst->n_name);
          i = 1;
      }
      nlst++;
    }

    return(i);
}


/*
 *  getkval(offset, ptr, size, refstr) - get a value out of the kernel.
 *    "offset" is the byte offset into the kernel for the desired value,
 *    "ptr" points to a buffer into which the value is retrieved,
 *    "size" is the size of the buffer (and the object to retrieve),
 *    "refstr" is a reference string used when printing error meessages,
 *        if "refstr" starts with a '!', then a failure on read will not
 *        be fatal (this may seem like a silly way to do things, but I
 *        really didn't want the overhead of another argument).
 *
 */

static int getkval(offset, ptr, size, refstr)

unsigned long offset;
int *ptr;
int size;
char *refstr;

{
    if (kvm_read(kd, offset, (char *) ptr, size) != size)
    {
      if (*refstr == '!')
      {
          return(0);
      }
      else
      {
          fprintf(stderr, "top: kvm_read for %s: %s\n",
              refstr, strerror(errno));
          quit(23);
      }
    }
    return(1);
}

/* comparison routine for qsort */

/*
 *  proc_compare - comparison function for "qsort"
 *    Compares the resource consumption of two processes using five
 *    distinct keys.  The keys (in descending order of importance) are:
 *    percent cpu, cpu ticks, state, resident set size, total virtual
 *    memory usage.  The process states are ordered as follows (from least
 *    to most important):  WAIT, zombie, sleep, stop, start, run.  The
 *    array declaration below maps a process state index into a number
 *    that reflects this ordering.
 */

static unsigned char sorted_state[] =
{
    0,        /* not used             */
    3,        /* sleep                */
    1,        /* ABANDONED (WAIT)     */
    6,        /* run                  */
    5,        /* start                */
    2,        /* zombie               */
    4 /* stop                 */
};

int
proc_compare(pp1, pp2)

struct proc **pp1;
struct proc **pp2;

{
    register struct kinfo_proc *p1;
    register struct kinfo_proc *p2;
    register int result;
    register pctcpu lresult;

    /* remove one level of indirection */
    p1 = *(struct kinfo_proc **) pp1;
    p2 = *(struct kinfo_proc **) pp2;

    /* compare percent cpu (pctcpu) */
    if ((lresult = PP(p2, p_pctcpu) - PP(p1, p_pctcpu)) == 0)
    {
      /* use cpticks to break the tie */
      if ((result = PP(p2, p_cpticks) - PP(p1, p_cpticks)) == 0)
      {
          /* use process state to break the tie */
          if ((result = sorted_state[(unsigned char) PP(p2, p_stat)] -
                        sorted_state[(unsigned char) PP(p1, p_stat)])  == 0)
          {
              /* use priority to break the tie */
              if ((result = PP(p2, p_priority) - PP(p1, p_priority)) == 0)
              {
                  /* use resident set size (rssize) to break the tie */
                  if ((result = VP(p2, vm_rssize) - VP(p1, vm_rssize)) == 0)
                  {
                      /* use total memory to break the tie */
                      result = PROCSIZE(p2) - PROCSIZE(p1);
                  }
              }
          }
      }
    }
    else
    {
      result = lresult < 0 ? -1 : 1;
    }

    return(result);
}


/*
 * proc_owner(pid) - returns the uid that owns process "pid", or -1 if
 *            the process does not exist.
 *            It is EXTREMLY IMPORTANT that this function work correctly.
 *            If top runs setuid root (as in SVR4), then this function
 *            is the only thing that stands in the way of a serious
 *            security problem.  It validates requests for the "kill"
 *            and "renice" commands.
 */

int proc_owner(pid)

int pid;

{
    register int cnt;
    register struct kinfo_proc **prefp;
    register struct kinfo_proc *pp;

    prefp = pref;
    cnt = pref_len;
    while (--cnt >= 0)
    {
      pp = *prefp++;
      if (PP(pp, p_pid) == (pid_t)pid)
      {
          return((int)EP(pp, e_pcred.p_ruid));
      }
    }
    return(-1);
}


#ifdef USE_SWAP
/*
 * swapmode is based on a program called swapinfo written
 * by Kevin Lahey <kml@rokkaku.atl.ga.us>.
 */

#define       SVAR(var) __STRING(var) /* to force expansion */
#define       KGET(idx,
r)                                                  \
      KGET1(idx, &var, sizeof(var), SVAR(var))
#define       KGET1(idx, p, s,
g)                                           \
      KGET2(nlst[idx].n_value, p, s, msg)
#define       KGET2(addr, p, s,
g)                                          \
      if (kvm_read(kd, (u_long)(addr), p, s) != s)                    \
              warnx("cannot read %s: %s", msg, kvm_geterr(kd))
#define       KGETRET(addr, p, s,
g)                                        \
      if (kvm_read(kd, (u_long)(addr), p, s) != s) {                  \
              warnx("cannot read %s: %s", msg, kvm_geterr(kd));       \
              return (0);                                             \
      }

int
swapmode()
{
      char *header;
      int hlen, nswap, nswdev, dmmax, nswapmap, niswap, niswdev;
      int s, e, div, i, l, avail, nfree, npfree, used;
      struct swdevt *sw;
      long blocksize, *perdev;
      struct map *swapmap, *kswapmap;
      struct mapent *mp, *freemp;

      KGET(VM_NSWAP, nswap);
      KGET(VM_NSWDEV, nswdev);
      KGET(VM_DMMAX, dmmax);
      KGET(VM_NSWAPMAP, nswapmap);
      KGET(VM_SWAPMAP, kswapmap);     /* kernel `swapmap' is a pointer */
      if ((sw = malloc(nswdev * sizeof(*sw))) == NULL ||
          (perdev = malloc(nswdev * sizeof(*perdev))) == NULL ||
          (freemp = mp = malloc(nswapmap * sizeof(*mp))) == NULL)
              err(1, "malloc");
      KGET1(VM_SWDEVT, sw, nswdev * sizeof(*sw), "swdevt");
      KGET2((long)kswapmap, mp, nswapmap * sizeof(*mp), "swapmap");

      /* Supports sequential swap */
      if (nlst[VM_NISWAP].n_value != 0) {
              KGET(VM_NISWAP, niswap);
              KGET(VM_NISWDEV, niswdev);
      } else {
              niswap = nswap;
              niswdev = nswdev;
      }

      /* First entry in map is `struct map'; rest are mapent's. */
      swapmap = (struct map *)mp;
      if (nswapmap != swapmap->m_limit - (struct mapent *)kswapmap)
              errx(1, "panic: nswapmap goof");

      /* Count up swap space. */
      nfree = 0;
      memset(perdev, 0, nswdev * sizeof(*perdev));
      for (mp++; mp->m_addr != 0; mp++) {
              s = mp->m_addr;                 /* start of swap region */
              e = mp->m_addr + mp->m_size;    /* end of region */
              nfree += mp->m_size;

              /*
               * Swap space is split up among the configured disks.
               *
               * For interleaved swap devices, the first dmmax blocks
               * of swap space some from the first disk, the next dmmax
               * blocks from the next, and so on up to niswap blocks.
               *
               * Sequential swap devices follow the interleaved devices
               * (i.e. blocks starting at niswap) in the order in which
               * they appear in the swdev table.  The size of each device
               * will be a multiple of dmmax.
               *
               * The list of free space joins adjacent free blocks,
               * ignoring device boundries.  If we want to keep track
               * of this information per device, we'll just have to
               * extract it ourselves.  We know that dmmax-sized chunks
               * cannot span device boundaries (interleaved or sequential)
               * so we loop over such chunks assigning them to devices.
               */
              i = -1;
              while (s < e) {         /* XXX this is inefficient */
                      int bound = roundup(s+1, dmmax);

                      if (bound > e)
                              bound = e;
                      if (bound <= niswap) {
                              /* Interleaved swap chunk. */
                              if (i == -1)
                                      i = (s / dmmax) % niswdev;
                              perdev[i] += bound - s;
                              if (++i >= niswdev)
                                      i = 0;
                      } else {
                              /* Sequential swap chunk. */
                              if (i < niswdev) {
                                      i = niswdev;
                                      l = niswap + sw[i].sw_nblks;
                              }
                              while (s >= l) {
                                      /* XXX don't die on bogus blocks */
                                      if (i == nswdev-1)
                                              break;
                                      l += sw[++i].sw_nblks;
                              }
                              perdev[i] += bound - s;
                      }
                      s = bound;
              }
      }

      header = getbsize(&hlen, &blocksize);
      div = blocksize / 512;
      avail = npfree = 0;
      for (i = 0; i < nswdev; i++) {
              int xsize, xfree;

              xsize = sw[i].sw_nblks;
              xfree = perdev[i];
              used = xsize - xfree;
              npfree++;
              avail += xsize;
      }

      /*
       * If only one partition has been set up via swapon(8), we don't
       * need to bother with totals.
       */
      used = avail - nfree;
      free (sw); free (freemp); free (perdev);
      return  (int)(((double)used / (double)avail * 100.0) + 0.5);
}


#endif