freebsd-nq/usr.bin/top/machine.c

/*
 * top - a top users display for Unix
 *
 * DESCRIPTION:
 * Originally written for BSD4.4 system by Christos Zoulas.
 * Ported to FreeBSD 2.x by Steven Wallace && Wolfram Schneider
 * Order support hacked in from top-3.5beta6/machine/m_aix41.c
 *   by Monte Mitzelfelt (for latest top see http://www.groupsys.com/topinfo/)
 *
 * AUTHOR:  Christos Zoulas <christos@ee.cornell.edu>
 *          Steven Wallace  <swallace@FreeBSD.org>
 *          Wolfram Schneider <wosch@FreeBSD.org>
 *          Thomas Moestl <tmoestl@gmx.net>
 *          Eitan Adler <eadler@FreeBSD.org>
 *
 * $FreeBSD$
 */

#include <sys/errno.h>
#include <sys/fcntl.h>
#include <sys/param.h>
#include <sys/priority.h>
#include <sys/proc.h>
#include <sys/resource.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/user.h>

#include <assert.h>
#include <err.h>
#include <libgen.h>
#include <kvm.h>
#include <math.h>
#include <paths.h>
#include <stdio.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <vis.h>

#include "top.h"
#include "display.h"
#include "machine.h"
#include "loadavg.h"
#include "screen.h"
#include "utils.h"
#include "layout.h"

#define GETSYSCTL(name, var) getsysctl(name, &(var), sizeof(var))

extern struct timeval timeout;
static int smpmode;
enum displaymodes displaymode;
static const int namelength = 10;
/* TOP_JID_LEN based on max of 999999 */
#define TOP_JID_LEN 6
#define TOP_SWAP_LEN 5

/* 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 */
};


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

/* what we consider to be process size: */
#define PROCSIZE(pp) ((pp)->ki_size / 1024)

#define RU(pp)	(&(pp)->ki_rusage)

#define	PCTCPU(pp) (pcpu[pp - pbase])

/* 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 */

static const char *state_abbrev[] = {
	"", "START", "RUN\0\0\0", "SLEEP", "STOP", "ZOMB", "WAIT", "LOCK"
};


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 load_avg  ccpu;

/* these are used in the get_ functions */

static int lastpid;

/* 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 */

static const char *procstatenames[] = {
	"", " starting, ", " running, ", " sleeping, ", " stopped, ",
	" zombie, ", " waiting, ", " lock, ",
	NULL
};
static int process_states[nitems(procstatenames)];

/* these are for detailing the cpu states */

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

/* these are for detailing the memory statistics */

static const char *memorynames[] = {
	"K Active, ", "K Inact, ", "K Laundry, ", "K Wired, ", "K Buf, ",
	"K Free", NULL
};
static int memory_stats[nitems(memorynames)];

static const char *arcnames[] = {
	"K Total, ", "K MFU, ", "K MRU, ", "K Anon, ", "K Header, ", "K Other",
	NULL
};
static int arc_stats[nitems(arcnames)];

static const char *carcnames[] = {
	"K Compressed, ", "K Uncompressed, ", ":1 Ratio, ",
	NULL
};
static int carc_stats[nitems(carcnames)];

static const char *swapnames[] = {
	"K Total, ", "K Used, ", "K Free, ", "% Inuse, ", "K In, ", "K Out",
	NULL
};
static int swap_stats[nitems(swapnames)];

static int has_swap;

/* 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;
static struct kinfo_proc *previous_procs;
static struct kinfo_proc **previous_pref;
static int previous_proc_count = 0;
static int previous_proc_count_max = 0;
static int previous_thread;

/* data used for recalculating pctcpu */
static double *pcpu;
static struct timespec proc_uptime;
static struct timeval proc_wall_time;
static struct timeval previous_wall_time;
static uint64_t previous_interval = 0;

/* total number of io operations */
static long total_inblock;
static long total_oublock;
static long total_majflt;

/* these are for getting the memory statistics */

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

/* define pagetok in terms of pageshift */

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

/* swap usage */
#define ki_swap(kip) \
    ((kip)->ki_swrss > (kip)->ki_rssize ? (kip)->ki_swrss - (kip)->ki_rssize : 0)

/*
 * Sorting orders.  The first element is the default.
 */
static const char *ordernames[] = {
	"cpu", "size", "res", "time", "pri", "threads",
	"total", "read", "write", "fault", "vcsw", "ivcsw",
	"jid", "swap", "pid", NULL
};

/* Per-cpu time states */
static int maxcpu;
static int maxid;
static int ncpus;
static unsigned long cpumask;
static long *times;
static long *pcpu_cp_time;
static long *pcpu_cp_old;
static long *pcpu_cp_diff;
static int *pcpu_cpu_states;

static int compare_swap(const void *a, const void *b);
static int compare_jid(const void *a, const void *b);
static int compare_pid(const void *a, const void *b);
static int compare_tid(const void *a, const void *b);
static const char *format_nice(const struct kinfo_proc *pp);
static void getsysctl(const char *name, void *ptr, size_t len);
static int swapmode(int *retavail, int *retfree);
static void update_layout(void);
static int find_uid(uid_t needle, int *haystack);

static int
find_uid(uid_t needle, int *haystack)
{
	size_t i = 0;

	for (; i < TOP_MAX_UIDS; ++i)
		if ((uid_t)haystack[i] == needle)
			return 1;
	return (0);
}

void
toggle_pcpustats(void)
{

	if (ncpus == 1)
		return;
	update_layout();
}

/* Adjust display based on ncpus and the ARC state. */
static void
update_layout(void)
{

	y_mem = 3;
	y_arc = 4;
	y_carc = 5;
	y_swap = 3 + arc_enabled + carc_enabled + has_swap;
	y_idlecursor = 4 + arc_enabled + carc_enabled + has_swap;
	y_message = 4 + arc_enabled + carc_enabled + has_swap;
	y_header = 5 + arc_enabled + carc_enabled + has_swap;
	y_procs = 6 + arc_enabled + carc_enabled + has_swap;
	Header_lines = 6 + arc_enabled + carc_enabled + has_swap;

	if (pcpu_stats) {
		y_mem += ncpus - 1;
		y_arc += ncpus - 1;
		y_carc += ncpus - 1;
		y_swap += ncpus - 1;
		y_idlecursor += ncpus - 1;
		y_message += ncpus - 1;
		y_header += ncpus - 1;
		y_procs += ncpus - 1;
		Header_lines += ncpus - 1;
	}
}

int
machine_init(struct statics *statics)
{
	int i, j, empty, pagesize;
	uint64_t arc_size;
	int carc_en, nswapdev;
	size_t size;

	size = sizeof(smpmode);
	if ((sysctlbyname("machdep.smp_active", &smpmode, &size,
	    NULL, 0) != 0 &&
	    sysctlbyname("kern.smp.active", &smpmode, &size,
	    NULL, 0) != 0) ||
	    size != sizeof(smpmode))
		smpmode = 0;

	size = sizeof(arc_size);
	if (sysctlbyname("kstat.zfs.misc.arcstats.size", &arc_size, &size,
	    NULL, 0) == 0 && arc_size != 0)
		arc_enabled = 1;
	size = sizeof(carc_en);
	if (arc_enabled &&
	    sysctlbyname("vfs.zfs.compressed_arc_enabled", &carc_en, &size,
	    NULL, 0) == 0 && carc_en == 1)
		carc_enabled = 1;

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

	size = sizeof(nswapdev);
	if (sysctlbyname("vm.nswapdev", &nswapdev, &size, NULL,
		0) == 0 && nswapdev != 0)
			has_swap = 1;

	GETSYSCTL("kern.ccpu", ccpu);

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

	pbase = NULL;
	pref = NULL;
	pcpu = NULL;
	nproc = 0;
	onproc = -1;

	/* get the page size 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;
	if (arc_enabled)
		statics->arc_names = arcnames;
	else
		statics->arc_names = NULL;
	if (carc_enabled)
		statics->carc_names = carcnames;
	else
		statics->carc_names = NULL;
	if (has_swap)
		statics->swap_names = swapnames;
	else
		statics->swap_names = NULL;
	statics->order_names = ordernames;

	/* Allocate state for per-CPU stats. */
	cpumask = 0;
	ncpus = 0;
	GETSYSCTL("kern.smp.maxcpus", maxcpu);
	times = calloc(maxcpu * CPUSTATES, sizeof(long));
	if (times == NULL)
		err(1, "calloc for kern.smp.maxcpus");
	size = sizeof(long) * maxcpu * CPUSTATES;
	if (sysctlbyname("kern.cp_times", times, &size, NULL, 0) == -1)
		err(1, "sysctlbyname kern.cp_times");
	pcpu_cp_time = calloc(1, size);
	maxid = (size / CPUSTATES / sizeof(long)) - 1;
	for (i = 0; i <= maxid; i++) {
		empty = 1;
		for (j = 0; empty && j < CPUSTATES; j++) {
			if (times[i * CPUSTATES + j] != 0)
				empty = 0;
		}
		if (!empty) {
			cpumask |= (1ul << i);
			ncpus++;
		}
	}
	assert(ncpus > 0);
	pcpu_cp_old = calloc(ncpus * CPUSTATES, sizeof(long));
	pcpu_cp_diff = calloc(ncpus * CPUSTATES, sizeof(long));
	pcpu_cpu_states = calloc(ncpus * CPUSTATES, sizeof(int));
	statics->ncpus = ncpus;

	update_layout();

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

char *
format_header(const char *uname_field)
{
	static struct sbuf* header = NULL;

	/* clean up from last time. */
	if (header != NULL) {
		sbuf_clear(header);
	} else {
		header = sbuf_new_auto();
	}

	switch (displaymode) {
	case DISP_CPU: {
		sbuf_printf(header, "  %s", ps.thread_id ? " THR" : "PID");
		sbuf_printf(header, "%*s", ps.jail ? TOP_JID_LEN : 0,
									ps.jail ? " JID" : "");
		sbuf_printf(header, " %-*.*s  ", namelength, namelength, uname_field);
		if (!ps.thread) {
			sbuf_cat(header, "THR ");
		}
		sbuf_cat(header, "PRI NICE   SIZE    RES ");
		if (ps.swap) {
			sbuf_printf(header, "%*s ", TOP_SWAP_LEN - 1, "SWAP");
		}
		sbuf_cat(header, "STATE    ");
		if (smpmode) {
			sbuf_cat(header, "C   ");
		}
		sbuf_cat(header, "TIME ");
		sbuf_printf(header, " %6s ", ps.wcpu ? "WCPU" : "CPU");
		sbuf_cat(header, "COMMAND");
		sbuf_finish(header);
		break;
	}
	case DISP_IO: {
		sbuf_printf(header, "  %s%*s %-*.*s",
			ps.thread_id ? " THR" : "PID",
		    ps.jail ? TOP_JID_LEN : 0, ps.jail ? " JID" : "",
		    namelength, namelength, uname_field);
		sbuf_cat(header, "   VCSW  IVCSW   READ  WRITE  FAULT  TOTAL PERCENT COMMAND");
		sbuf_finish(header);
		break;
	}
	case DISP_MAX:
		assert("displaymode must not be set to DISP_MAX");
	}

	return sbuf_data(header);
}

static int swappgsin = -1;
static int swappgsout = -1;


void
get_system_info(struct system_info *si)
{
	struct loadavg sysload;
	int mib[2];
	struct timeval boottime;
	uint64_t arc_stat, arc_stat2;
	int i, j;
	size_t size;

	/* get the CPU stats */
	size = (maxid + 1) * CPUSTATES * sizeof(long);
	if (sysctlbyname("kern.cp_times", pcpu_cp_time, &size, NULL, 0) == -1)
		err(1, "sysctlbyname kern.cp_times");
	GETSYSCTL("kern.cp_time", cp_time);
	GETSYSCTL("vm.loadavg", sysload);
	GETSYSCTL("kern.lastpid", lastpid);

	/* convert load averages to doubles */
	for (i = 0; i < 3; i++)
		si->load_avg[i] = (double)sysload.ldavg[i] / sysload.fscale;

	/* convert cp_time counts to percentages */
	for (i = j = 0; i <= maxid; i++) {
		if ((cpumask & (1ul << i)) == 0)
			continue;
		percentages(CPUSTATES, &pcpu_cpu_states[j * CPUSTATES],
		    &pcpu_cp_time[j * CPUSTATES],
		    &pcpu_cp_old[j * CPUSTATES],
		    &pcpu_cp_diff[j * CPUSTATES]);
		j++;
	}
	percentages(CPUSTATES, cpu_states, cp_time, cp_old, cp_diff);

	/* sum memory & swap statistics */
	{
		static unsigned int swap_delay = 0;
		static int swapavail = 0;
		static int swapfree = 0;
		static long bufspace = 0;
		static uint64_t nspgsin, nspgsout;

		GETSYSCTL("vfs.bufspace", bufspace);
		GETSYSCTL("vm.stats.vm.v_active_count", memory_stats[0]);
		GETSYSCTL("vm.stats.vm.v_inactive_count", memory_stats[1]);
		GETSYSCTL("vm.stats.vm.v_laundry_count", memory_stats[2]);
		GETSYSCTL("vm.stats.vm.v_wire_count", memory_stats[3]);
		GETSYSCTL("vm.stats.vm.v_free_count", memory_stats[5]);
		GETSYSCTL("vm.stats.vm.v_swappgsin", nspgsin);
		GETSYSCTL("vm.stats.vm.v_swappgsout", nspgsout);
		/* convert memory stats to Kbytes */
		memory_stats[0] = pagetok(memory_stats[0]);
		memory_stats[1] = pagetok(memory_stats[1]);
		memory_stats[2] = pagetok(memory_stats[2]);
		memory_stats[3] = pagetok(memory_stats[3]);
		memory_stats[4] = bufspace / 1024;
		memory_stats[5] = pagetok(memory_stats[5]);
		memory_stats[6] = -1;

		/* first interval */
		if (swappgsin < 0) {
			swap_stats[4] = 0;
			swap_stats[5] = 0;
		}

		/* compute differences between old and new swap statistic */
		else {
			swap_stats[4] = pagetok(((nspgsin - swappgsin)));
			swap_stats[5] = pagetok(((nspgsout - swappgsout)));
		}

		swappgsin = nspgsin;
		swappgsout = nspgsout;

		/* call CPU heavy swapmode() only for changes */
		if (swap_stats[4] > 0 || swap_stats[5] > 0 || swap_delay == 0) {
			swap_stats[3] = swapmode(&swapavail, &swapfree);
			swap_stats[0] = swapavail;
			swap_stats[1] = swapavail - swapfree;
			swap_stats[2] = swapfree;
		}
		swap_delay = 1;
		swap_stats[6] = -1;
	}

	if (arc_enabled) {
		GETSYSCTL("kstat.zfs.misc.arcstats.size", arc_stat);
		arc_stats[0] = arc_stat >> 10;
		GETSYSCTL("vfs.zfs.mfu_size", arc_stat);
		arc_stats[1] = arc_stat >> 10;
		GETSYSCTL("vfs.zfs.mru_size", arc_stat);
		arc_stats[2] = arc_stat >> 10;
		GETSYSCTL("vfs.zfs.anon_size", arc_stat);
		arc_stats[3] = arc_stat >> 10;
		GETSYSCTL("kstat.zfs.misc.arcstats.hdr_size", arc_stat);
		GETSYSCTL("kstat.zfs.misc.arcstats.l2_hdr_size", arc_stat2);
		arc_stats[4] = (arc_stat + arc_stat2) >> 10;
		GETSYSCTL("kstat.zfs.misc.arcstats.bonus_size", arc_stat);
		arc_stats[5] = arc_stat >> 10;
		GETSYSCTL("kstat.zfs.misc.arcstats.dnode_size", arc_stat);
		arc_stats[5] += arc_stat >> 10;
		GETSYSCTL("kstat.zfs.misc.arcstats.dbuf_size", arc_stat);
		arc_stats[5] += arc_stat >> 10;
		si->arc = arc_stats;
	}
	if (carc_enabled) {
		GETSYSCTL("kstat.zfs.misc.arcstats.compressed_size", arc_stat);
		carc_stats[0] = arc_stat >> 10;
		carc_stats[2] = arc_stat >> 10; /* For ratio */
		GETSYSCTL("kstat.zfs.misc.arcstats.uncompressed_size", arc_stat);
		carc_stats[1] = arc_stat >> 10;
		si->carc = carc_stats;
	}

	/* set arrays and strings */
	if (pcpu_stats) {
		si->cpustates = pcpu_cpu_states;
		si->ncpus = ncpus;
	} else {
		si->cpustates = cpu_states;
		si->ncpus = 1;
	}
	si->memory = memory_stats;
	si->swap = swap_stats;


	if (lastpid > 0) {
		si->last_pid = lastpid;
	} else {
		si->last_pid = -1;
	}

	/*
	 * Print how long system has been up.
	 * (Found by looking getting "boottime" from the kernel)
	 */
	mib[0] = CTL_KERN;
	mib[1] = KERN_BOOTTIME;
	size = sizeof(boottime);
	if (sysctl(mib, nitems(mib), &boottime, &size, NULL, 0) != -1 &&
	    boottime.tv_sec != 0) {
		si->boottime = boottime;
	} else {
		si->boottime.tv_sec = -1;
	}
}

#define NOPROC	((void *)-1)

/*
 * We need to compare data from the old process entry with the new
 * process entry.
 * To facilitate doing this quickly we stash a pointer in the kinfo_proc
 * structure to cache the mapping.  We also use a negative cache pointer
 * of NOPROC to avoid duplicate lookups.
 * XXX: this could be done when the actual processes are fetched, we do
 * it here out of laziness.
 */
static const struct kinfo_proc *
get_old_proc(struct kinfo_proc *pp)
{
	const struct kinfo_proc * const *oldpp, *oldp;

	/*
	 * If this is the first fetch of the kinfo_procs then we don't have
	 * any previous entries.
	 */
	if (previous_proc_count == 0)
		return (NULL);
	/* negative cache? */
	if (pp->ki_udata == NOPROC)
		return (NULL);
	/* cached? */
	if (pp->ki_udata != NULL)
		return (pp->ki_udata);
	/*
	 * Not cached,
	 * 1) look up based on pid.
	 * 2) compare process start.
	 * If we fail here, then setup a negative cache entry, otherwise
	 * cache it.
	 */
	oldpp = bsearch(&pp, previous_pref, previous_proc_count,
	    sizeof(*previous_pref), ps.thread ? compare_tid : compare_pid);
	if (oldpp == NULL) {
		pp->ki_udata = NOPROC;
		return (NULL);
	}
	oldp = *oldpp;
	if (memcmp(&oldp->ki_start, &pp->ki_start, sizeof(pp->ki_start)) != 0) {
		pp->ki_udata = NOPROC;
		return (NULL);
	}
	pp->ki_udata = __DECONST(void *, oldp);
	return (oldp);
}

/*
 * Return the total amount of IO done in blocks in/out and faults.
 * store the values individually in the pointers passed in.
 */
static long
get_io_stats(const struct kinfo_proc *pp, long *inp, long *oup, long *flp,
    long *vcsw, long *ivcsw)
{
	const struct kinfo_proc *oldp;
	static struct kinfo_proc dummy;
	long ret;

	oldp = get_old_proc(__DECONST(struct kinfo_proc *, pp));
	if (oldp == NULL) {
		memset(&dummy, 0, sizeof(dummy));
		oldp = &dummy;
	}
	*inp = RU(pp)->ru_inblock - RU(oldp)->ru_inblock;
	*oup = RU(pp)->ru_oublock - RU(oldp)->ru_oublock;
	*flp = RU(pp)->ru_majflt - RU(oldp)->ru_majflt;
	*vcsw = RU(pp)->ru_nvcsw - RU(oldp)->ru_nvcsw;
	*ivcsw = RU(pp)->ru_nivcsw - RU(oldp)->ru_nivcsw;
	ret =
	    (RU(pp)->ru_inblock - RU(oldp)->ru_inblock) +
	    (RU(pp)->ru_oublock - RU(oldp)->ru_oublock) +
	    (RU(pp)->ru_majflt - RU(oldp)->ru_majflt);
	return (ret);
}

/*
 * If there was a previous update, use the delta in ki_runtime over
 * the previous interval to calculate pctcpu.  Otherwise, fall back
 * to using the kernel's ki_pctcpu.
 */
static double
proc_calc_pctcpu(struct kinfo_proc *pp)
{
	const struct kinfo_proc *oldp;

	if (previous_interval != 0) {
		oldp = get_old_proc(pp);
		if (oldp != NULL)
			return ((double)(pp->ki_runtime - oldp->ki_runtime)
			    / previous_interval);

		/*
		 * If this process/thread was created during the previous
		 * interval, charge it's total runtime to the previous
		 * interval.
		 */
		else if (pp->ki_start.tv_sec > previous_wall_time.tv_sec ||
		    (pp->ki_start.tv_sec == previous_wall_time.tv_sec &&
		    pp->ki_start.tv_usec >= previous_wall_time.tv_usec))
			return ((double)pp->ki_runtime / previous_interval);
	}
	return (pctdouble(pp->ki_pctcpu));
}

/*
 * Return true if this process has used any CPU time since the
 * previous update.
 */
static int
proc_used_cpu(struct kinfo_proc *pp)
{
	const struct kinfo_proc *oldp;

	oldp = get_old_proc(pp);
	if (oldp == NULL)
		return (PCTCPU(pp) != 0);
	return (pp->ki_runtime != oldp->ki_runtime ||
	    RU(pp)->ru_nvcsw != RU(oldp)->ru_nvcsw ||
	    RU(pp)->ru_nivcsw != RU(oldp)->ru_nivcsw);
}

/*
 * Return the total number of block in/out and faults by a process.
 */
static long
get_io_total(const struct kinfo_proc *pp)
{
	long dummy;

	return (get_io_stats(pp, &dummy, &dummy, &dummy, &dummy, &dummy));
}

static struct handle handle;

void *
get_process_info(struct system_info *si, struct process_select *sel,
    int (*compare)(const void *, const void *))
{
	int i;
	int total_procs;
	long p_io;
	long p_inblock, p_oublock, p_majflt, p_vcsw, p_ivcsw;
	long nsec;
	int active_procs;
	struct kinfo_proc **prefp;
	struct kinfo_proc *pp;
	struct timespec previous_proc_uptime;

	/*
	 * If thread state was toggled, don't cache the previous processes.
	 */
	if (previous_thread != sel->thread)
		nproc = 0;
	previous_thread = sel->thread;

	/*
	 * Save the previous process info.
	 */
	if (previous_proc_count_max < nproc) {
		free(previous_procs);
		previous_procs = calloc(nproc, sizeof(*previous_procs));
		free(previous_pref);
		previous_pref = calloc(nproc, sizeof(*previous_pref));
		if (previous_procs == NULL || previous_pref == NULL) {
			fprintf(stderr, "top: Out of memory.\n");
			quit(TOP_EX_SYS_ERROR);
		}
		previous_proc_count_max = nproc;
	}
	if (nproc) {
		for (i = 0; i < nproc; i++)
			previous_pref[i] = &previous_procs[i];
		memcpy(previous_procs, pbase, nproc * sizeof(*previous_procs));
		qsort(previous_pref, nproc, sizeof(*previous_pref),
		    ps.thread ? compare_tid : compare_pid);
	}
	previous_proc_count = nproc;
	previous_proc_uptime = proc_uptime;
	previous_wall_time = proc_wall_time;
	previous_interval = 0;

	pbase = kvm_getprocs(kd, sel->thread ? KERN_PROC_ALL : KERN_PROC_PROC,
	    0, &nproc);
	gettimeofday(&proc_wall_time, NULL);
	if (clock_gettime(CLOCK_UPTIME, &proc_uptime) != 0)
		memset(&proc_uptime, 0, sizeof(proc_uptime));
	else if (previous_proc_uptime.tv_sec != 0 &&
	    previous_proc_uptime.tv_nsec != 0) {
		previous_interval = (proc_uptime.tv_sec -
		    previous_proc_uptime.tv_sec) * 1000000;
		nsec = proc_uptime.tv_nsec - previous_proc_uptime.tv_nsec;
		if (nsec < 0) {
			previous_interval -= 1000000;
			nsec += 1000000000;
		}
		previous_interval += nsec / 1000;
	}
	if (nproc > onproc) {
		pref = realloc(pref, sizeof(*pref) * nproc);
		pcpu = realloc(pcpu, sizeof(*pcpu) * nproc);
		onproc = nproc;
	}
	if (pref == NULL || pbase == NULL || pcpu == NULL) {
		fprintf(stderr, "top: Out of memory.\n");
		quit(TOP_EX_SYS_ERROR);
	}
	/* get a pointer to the states summary array */
	si->procstates = process_states;

	/* count up process states and get pointers to interesting procs */
	total_procs = 0;
	active_procs = 0;
	total_inblock = 0;
	total_oublock = 0;
	total_majflt = 0;
	memset(process_states, 0, sizeof(process_states));
	prefp = pref;
	for (pp = pbase, i = 0; i < nproc; pp++, i++) {

		if (pp->ki_stat == 0)
			/* not in use */
			continue;

		if (!sel->self && pp->ki_pid == mypid && sel->pid == -1)
			/* skip self */
			continue;

		if (!sel->system && (pp->ki_flag & P_SYSTEM) && sel->pid == -1)
			/* skip system process */
			continue;

		p_io = get_io_stats(pp, &p_inblock, &p_oublock, &p_majflt,
		    &p_vcsw, &p_ivcsw);
		total_inblock += p_inblock;
		total_oublock += p_oublock;
		total_majflt += p_majflt;
		total_procs++;
		process_states[(unsigned char)pp->ki_stat]++;

		if (pp->ki_stat == SZOMB)
			/* skip zombies */
			continue;

		if (!sel->kidle && pp->ki_tdflags & TDF_IDLETD && sel->pid == -1)
			/* skip kernel idle process */
			continue;

		PCTCPU(pp) = proc_calc_pctcpu(pp);
		if (sel->thread && PCTCPU(pp) > 1.0)
			PCTCPU(pp) = 1.0;
		if (displaymode == DISP_CPU && !sel->idle &&
		    (!proc_used_cpu(pp) ||
		     pp->ki_stat == SSTOP || pp->ki_stat == SIDL))
			/* skip idle or non-running processes */
			continue;

		if (displaymode == DISP_IO && !sel->idle && p_io == 0)
			/* skip processes that aren't doing I/O */
			continue;

		if (sel->jid != -1 && pp->ki_jid != sel->jid)
			/* skip proc. that don't belong to the selected JID */
			continue;

		if (sel->uid[0] != -1 && !find_uid(pp->ki_ruid, sel->uid))
			/* skip proc. that don't belong to the selected UID */
			continue;

		if (sel->pid != -1 && pp->ki_pid != sel->pid)
			continue;

		*prefp++ = pp;
		active_procs++;
	}

	/* if requested, sort the "interesting" processes */
	if (compare != NULL)
		qsort(pref, active_procs, sizeof(*pref), compare);

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

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

char *
format_next_process(struct handle * xhandle, char *(*get_userid)(int), int flags)
{
	struct kinfo_proc *pp;
	const struct kinfo_proc *oldp;
	long cputime;
	char status[22];
	size_t state;
	struct rusage ru, *rup;
	long p_tot, s_tot;
	char *cmdbuf = NULL;
	char **args;
	static struct sbuf* procbuf = NULL;

	/* clean up from last time. */
	if (procbuf != NULL) {
		sbuf_clear(procbuf);
	} else {
		procbuf = sbuf_new_auto();
	}


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

	/* get the process's command name */
	if ((pp->ki_flag & P_INMEM) == 0) {
		/*
		 * Print swapped processes as <pname>
		 */
		size_t len;

		len = strlen(pp->ki_comm);
		if (len > sizeof(pp->ki_comm) - 3)
			len = sizeof(pp->ki_comm) - 3;
		memmove(pp->ki_comm + 1, pp->ki_comm, len);
		pp->ki_comm[0] = '<';
		pp->ki_comm[len + 1] = '>';
		pp->ki_comm[len + 2] = '\0';
	}

	/*
	 * Convert the process's runtime from microseconds to seconds.  This
	 * time includes the interrupt time although that is not wanted here.
	 * ps(1) is similarly sloppy.
	 */
	cputime = (pp->ki_runtime + 500000) / 1000000;

	/* generate "STATE" field */
	switch (state = pp->ki_stat) {
	case SRUN:
		if (smpmode && pp->ki_oncpu != NOCPU)
			sprintf(status, "CPU%d", pp->ki_oncpu);
		else
			strcpy(status, "RUN");
		break;
	case SLOCK:
		if (pp->ki_kiflag & KI_LOCKBLOCK) {
			sprintf(status, "*%.6s", pp->ki_lockname);
			break;
		}
		/* fall through */
	case SSLEEP:
		sprintf(status, "%.6s", pp->ki_wmesg);
		break;
	default:

		if (state < nitems(state_abbrev)) {
			sprintf(status, "%.6s", state_abbrev[state]);
		} else {
			sprintf(status, "?%5zu", state);
		}
		break;
	}

	cmdbuf = calloc(screen_width + 1, 1);
	if (cmdbuf == NULL) {
		warn("calloc(%d)", screen_width + 1);
		return NULL;
	}

	if (!(flags & FMT_SHOWARGS)) {
		if (ps.thread && pp->ki_flag & P_HADTHREADS &&
		    pp->ki_tdname[0]) {
			snprintf(cmdbuf, screen_width, "%s{%s%s}", pp->ki_comm,
			    pp->ki_tdname, pp->ki_moretdname);
		} else {
			snprintf(cmdbuf, screen_width, "%s", pp->ki_comm);
		}
	} else {
		if (pp->ki_flag & P_SYSTEM ||
		    (args = kvm_getargv(kd, pp, screen_width)) == NULL ||
		    !(*args)) {
			if (ps.thread && pp->ki_flag & P_HADTHREADS &&
		    	    pp->ki_tdname[0]) {
				snprintf(cmdbuf, screen_width,
				    "[%s{%s%s}]", pp->ki_comm, pp->ki_tdname,
				    pp->ki_moretdname);
			} else {
				snprintf(cmdbuf, screen_width,
				    "[%s]", pp->ki_comm);
			}
		} else {
			const char *src;
			char *dst, *argbuf;
			const char *cmd;
			size_t argbuflen;
			size_t len;

			argbuflen = screen_width * 4;
			argbuf = calloc(argbuflen + 1, 1);
			if (argbuf == NULL) {
				warn("calloc(%zu)", argbuflen + 1);
				free(cmdbuf);
				return NULL;
			}

			dst = argbuf;

			/* Extract cmd name from argv */
			cmd = basename(*args);

			for (; (src = *args++) != NULL; ) {
				if (*src == '\0')
					continue;
				len = (argbuflen - (dst - argbuf) - 1) / 4;
				strvisx(dst, src,
				    MIN(strlen(src), len),
				    VIS_NL | VIS_CSTYLE);
				while (*dst != '\0')
					dst++;
				if ((argbuflen - (dst - argbuf) - 1) / 4 > 0)
					*dst++ = ' '; /* add delimiting space */
			}
			if (dst != argbuf && dst[-1] == ' ')
				dst--;
			*dst = '\0';

			if (strcmp(cmd, pp->ki_comm) != 0) {
				if (ps.thread && pp->ki_flag & P_HADTHREADS &&
				    pp->ki_tdname[0])
					snprintf(cmdbuf, screen_width,
					    "%s (%s){%s%s}", argbuf,
					    pp->ki_comm, pp->ki_tdname,
					    pp->ki_moretdname);
				else
					snprintf(cmdbuf, screen_width,
					    "%s (%s)", argbuf, pp->ki_comm);
			} else {
				if (ps.thread && pp->ki_flag & P_HADTHREADS &&
				    pp->ki_tdname[0])
					snprintf(cmdbuf, screen_width,
					    "%s{%s%s}", argbuf, pp->ki_tdname,
					    pp->ki_moretdname);
				else
					strlcpy(cmdbuf, argbuf, screen_width);
			}
			free(argbuf);
		}
	}

	if (displaymode == DISP_IO) {
		oldp = get_old_proc(pp);
		if (oldp != NULL) {
			ru.ru_inblock = RU(pp)->ru_inblock -
			    RU(oldp)->ru_inblock;
			ru.ru_oublock = RU(pp)->ru_oublock -
			    RU(oldp)->ru_oublock;
			ru.ru_majflt = RU(pp)->ru_majflt - RU(oldp)->ru_majflt;
			ru.ru_nvcsw = RU(pp)->ru_nvcsw - RU(oldp)->ru_nvcsw;
			ru.ru_nivcsw = RU(pp)->ru_nivcsw - RU(oldp)->ru_nivcsw;
			rup = &ru;
		} else {
			rup = RU(pp);
		}
		p_tot = rup->ru_inblock + rup->ru_oublock + rup->ru_majflt;
		s_tot = total_inblock + total_oublock + total_majflt;

		sbuf_printf(procbuf, "%5d ", (ps.thread_id) ? pp->ki_tid : pp->ki_pid);

		if (ps.jail) {
			sbuf_printf(procbuf, "%*d ", TOP_JID_LEN - 1, pp->ki_jid);
		}
		sbuf_printf(procbuf, "%-*.*s", namelength, namelength, (*get_userid)(pp->ki_ruid));
		sbuf_printf(procbuf, "%6ld ", rup->ru_nvcsw);
		sbuf_printf(procbuf, "%6ld ", rup->ru_nivcsw);
		sbuf_printf(procbuf, "%6ld ", rup->ru_inblock);
		sbuf_printf(procbuf, "%6ld ", rup->ru_oublock);
		sbuf_printf(procbuf, "%6ld ", rup->ru_majflt);
		sbuf_printf(procbuf, "%6ld ", p_tot);
		sbuf_printf(procbuf, "%6.2f%% ", s_tot == 0 ? 0.0 : (p_tot * 100.0 / s_tot));

	} else {
		sbuf_printf(procbuf, "%5d ", (ps.thread_id) ? pp->ki_tid : pp->ki_pid);
		if (ps.jail) {
			sbuf_printf(procbuf, "%*d ", TOP_JID_LEN - 1, pp->ki_jid);
		}
		sbuf_printf(procbuf, "%-*.*s ", namelength, namelength, (*get_userid)(pp->ki_ruid));

		if (!ps.thread) {
			sbuf_printf(procbuf, "%4d ", pp->ki_numthreads);
		} else {
			sbuf_printf(procbuf, " ");
		}

		sbuf_printf(procbuf, "%3d ", pp->ki_pri.pri_level - PZERO);
		sbuf_printf(procbuf, "%4s", format_nice(pp));
		sbuf_printf(procbuf, "%7s ", format_k(PROCSIZE(pp)));
		sbuf_printf(procbuf, "%6s ", format_k(pagetok(pp->ki_rssize)));
		if (ps.swap) {
			sbuf_printf(procbuf, "%*s ",
				TOP_SWAP_LEN - 1,
				format_k(pagetok(ki_swap(pp))));
		}
		sbuf_printf(procbuf, "%-6.6s ", status);
		if (smpmode) {
			int cpu;
			if (state == SRUN && pp->ki_oncpu != NOCPU) {
				cpu = pp->ki_oncpu;
			} else {
				cpu = pp->ki_lastcpu;
			}
			sbuf_printf(procbuf, "%3d ", cpu);
		}
		sbuf_printf(procbuf, "%6s ", format_time(cputime));
		sbuf_printf(procbuf, "%6.2f%% ", ps.wcpu ? 100.0 * weighted_cpu(PCTCPU(pp), pp) : 100.0 * PCTCPU(pp));
	}
	sbuf_printf(procbuf, "%s", printable(cmdbuf));
	free(cmdbuf);
	return (sbuf_data(procbuf));
}

static void
getsysctl(const char *name, void *ptr, size_t len)
{
	size_t nlen = len;

	if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
		fprintf(stderr, "top: sysctl(%s...) failed: %s\n", name,
		    strerror(errno));
		quit(TOP_EX_SYS_ERROR);
	}
	if (nlen != len) {
		fprintf(stderr, "top: sysctl(%s...) expected %lu, got %lu\n",
		    name, (unsigned long)len, (unsigned long)nlen);
		quit(TOP_EX_SYS_ERROR);
	}
}

static const char *
format_nice(const struct kinfo_proc *pp)
{
	const char *fifo, *kproc;
	int rtpri;
	static char nicebuf[4 + 1];

	fifo = PRI_NEED_RR(pp->ki_pri.pri_class) ? "" : "F";
	kproc = (pp->ki_flag & P_KPROC) ? "k" : "";
	switch (PRI_BASE(pp->ki_pri.pri_class)) {
	case PRI_ITHD:
		return ("-");
	case PRI_REALTIME:
		/*
		 * XXX: the kernel doesn't tell us the original rtprio and
		 * doesn't really know what it was, so to recover it we
		 * must be more chummy with the implementation than the
		 * implementation is with itself.  pri_user gives a
		 * constant "base" priority, but is only initialized
		 * properly for user threads.  pri_native gives what the
		 * kernel calls the "base" priority, but it isn't constant
		 * since it is changed by priority propagation.  pri_native
		 * also isn't properly initialized for all threads, but it
		 * is properly initialized for kernel realtime and idletime
		 * threads.  Thus we use pri_user for the base priority of
		 * user threads (it is always correct) and pri_native for
		 * the base priority of kernel realtime and idletime threads
		 * (there is nothing better, and it is usually correct).
		 *
		 * The field width and thus the buffer are too small for
		 * values like "kr31F", but such values shouldn't occur,
		 * and if they do then the tailing "F" is not displayed.
		 */
		rtpri = ((pp->ki_flag & P_KPROC) ? pp->ki_pri.pri_native :
		    pp->ki_pri.pri_user) - PRI_MIN_REALTIME;
		snprintf(nicebuf, sizeof(nicebuf), "%sr%d%s",
		    kproc, rtpri, fifo);
		break;
	case PRI_TIMESHARE:
		if (pp->ki_flag & P_KPROC)
			return ("-");
		snprintf(nicebuf, sizeof(nicebuf), "%d", pp->ki_nice - NZERO);
		break;
	case PRI_IDLE:
		/* XXX: as above. */
		rtpri = ((pp->ki_flag & P_KPROC) ? pp->ki_pri.pri_native :
		    pp->ki_pri.pri_user) - PRI_MIN_IDLE;
		snprintf(nicebuf, sizeof(nicebuf), "%si%d%s",
		    kproc, rtpri, fifo);
		break;
	default:
		return ("?");
	}
	return (nicebuf);
}

/* comparison routines for qsort */

static int
compare_pid(const void *p1, const void *p2)
{
	const struct kinfo_proc * const *pp1 = p1;
	const struct kinfo_proc * const *pp2 = p2;

	assert((*pp2)->ki_pid >= 0 && (*pp1)->ki_pid >= 0);

	return ((*pp1)->ki_pid - (*pp2)->ki_pid);
}

static int
compare_tid(const void *p1, const void *p2)
{
	const struct kinfo_proc * const *pp1 = p1;
	const struct kinfo_proc * const *pp2 = p2;

	assert((*pp2)->ki_tid >= 0 && (*pp1)->ki_tid >= 0);

	return ((*pp1)->ki_tid - (*pp2)->ki_tid);
}

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


#define ORDERKEY_PCTCPU(a, b) do { \
	double diff; \
	if (ps.wcpu) \
		diff = weighted_cpu(PCTCPU((b)), (b)) - \
		    weighted_cpu(PCTCPU((a)), (a)); \
	else \
		diff = PCTCPU((b)) - PCTCPU((a)); \
	if (diff != 0) \
		return (diff > 0 ? 1 : -1); \
} while (0)

#define ORDERKEY_CPTICKS(a, b) do { \
	int64_t diff = (int64_t)(b)->ki_runtime - (int64_t)(a)->ki_runtime; \
	if (diff != 0) \
		return (diff > 0 ? 1 : -1); \
} while (0)

#define ORDERKEY_STATE(a, b) do { \
	int diff = sorted_state[(unsigned char)(b)->ki_stat] - sorted_state[(unsigned char)(a)->ki_stat]; \
	if (diff != 0) \
		return (diff > 0 ? 1 : -1); \
} while (0)

#define ORDERKEY_PRIO(a, b) do { \
	int diff = (int)(b)->ki_pri.pri_level - (int)(a)->ki_pri.pri_level; \
	if (diff != 0) \
		return (diff > 0 ? 1 : -1); \
} while (0)

#define	ORDERKEY_THREADS(a, b) do { \
	int diff = (int)(b)->ki_numthreads - (int)(a)->ki_numthreads; \
	if (diff != 0) \
		return (diff > 0 ? 1 : -1); \
} while (0)

#define ORDERKEY_RSSIZE(a, b) do { \
	long diff = (long)(b)->ki_rssize - (long)(a)->ki_rssize; \
	if (diff != 0) \
		return (diff > 0 ? 1 : -1); \
} while (0)

#define ORDERKEY_MEM(a, b) do { \
	long diff = (long)PROCSIZE((b)) - (long)PROCSIZE((a)); \
	if (diff != 0) \
		return (diff > 0 ? 1 : -1); \
} while (0)

#define ORDERKEY_JID(a, b) do { \
	int diff = (int)(b)->ki_jid - (int)(a)->ki_jid; \
	if (diff != 0) \
		return (diff > 0 ? 1 : -1); \
} while (0)

#define ORDERKEY_SWAP(a, b) do { \
	int diff = (int)ki_swap(b) - (int)ki_swap(a); \
	if (diff != 0) \
		return (diff > 0 ? 1 : -1); \
} while (0)

/* compare_cpu - the comparison function for sorting by cpu percentage */

static int
compare_cpu(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;

	ORDERKEY_PCTCPU(p1, p2);
	ORDERKEY_CPTICKS(p1, p2);
	ORDERKEY_STATE(p1, p2);
	ORDERKEY_PRIO(p1, p2);
	ORDERKEY_RSSIZE(p1, p2);
	ORDERKEY_MEM(p1, p2);

	return (0);
}

/* compare_size - the comparison function for sorting by total memory usage */

static int
compare_size(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;

	ORDERKEY_MEM(p1, p2);
	ORDERKEY_RSSIZE(p1, p2);
	ORDERKEY_PCTCPU(p1, p2);
	ORDERKEY_CPTICKS(p1, p2);
	ORDERKEY_STATE(p1, p2);
	ORDERKEY_PRIO(p1, p2);

	return (0);
}

/* compare_res - the comparison function for sorting by resident set size */

static int
compare_res(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;

	ORDERKEY_RSSIZE(p1, p2);
	ORDERKEY_MEM(p1, p2);
	ORDERKEY_PCTCPU(p1, p2);
	ORDERKEY_CPTICKS(p1, p2);
	ORDERKEY_STATE(p1, p2);
	ORDERKEY_PRIO(p1, p2);

	return (0);
}

/* compare_time - the comparison function for sorting by total cpu time */

static int
compare_time(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const  *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *) arg2;

	ORDERKEY_CPTICKS(p1, p2);
	ORDERKEY_PCTCPU(p1, p2);
	ORDERKEY_STATE(p1, p2);
	ORDERKEY_PRIO(p1, p2);
	ORDERKEY_RSSIZE(p1, p2);
	ORDERKEY_MEM(p1, p2);

	return (0);
}

/* compare_prio - the comparison function for sorting by priority */

static int
compare_prio(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;

	ORDERKEY_PRIO(p1, p2);
	ORDERKEY_CPTICKS(p1, p2);
	ORDERKEY_PCTCPU(p1, p2);
	ORDERKEY_STATE(p1, p2);
	ORDERKEY_RSSIZE(p1, p2);
	ORDERKEY_MEM(p1, p2);

	return (0);
}

/* compare_threads - the comparison function for sorting by threads */
static int
compare_threads(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;

	ORDERKEY_THREADS(p1, p2);
	ORDERKEY_PCTCPU(p1, p2);
	ORDERKEY_CPTICKS(p1, p2);
	ORDERKEY_STATE(p1, p2);
	ORDERKEY_PRIO(p1, p2);
	ORDERKEY_RSSIZE(p1, p2);
	ORDERKEY_MEM(p1, p2);

	return (0);
}

/* compare_jid - the comparison function for sorting by jid */
static int
compare_jid(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;

	ORDERKEY_JID(p1, p2);
	ORDERKEY_PCTCPU(p1, p2);
	ORDERKEY_CPTICKS(p1, p2);
	ORDERKEY_STATE(p1, p2);
	ORDERKEY_PRIO(p1, p2);
	ORDERKEY_RSSIZE(p1, p2);
	ORDERKEY_MEM(p1, p2);

	return (0);
}

/* compare_swap - the comparison function for sorting by swap */
static int
compare_swap(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;

	ORDERKEY_SWAP(p1, p2);
	ORDERKEY_PCTCPU(p1, p2);
	ORDERKEY_CPTICKS(p1, p2);
	ORDERKEY_STATE(p1, p2);
	ORDERKEY_PRIO(p1, p2);
	ORDERKEY_RSSIZE(p1, p2);
	ORDERKEY_MEM(p1, p2);

	return (0);
}

/* assorted comparison functions for sorting by i/o */

static int
compare_iototal(const void *arg1, const void *arg2)
{
	const struct kinfo_proc * const p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc * const p2 = *(const struct kinfo_proc * const *)arg2;

	return (get_io_total(p2) - get_io_total(p1));
}

static int
compare_ioread(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;
	long dummy, inp1, inp2;

	(void) get_io_stats(p1, &inp1, &dummy, &dummy, &dummy, &dummy);
	(void) get_io_stats(p2, &inp2, &dummy, &dummy, &dummy, &dummy);

	return (inp2 - inp1);
}

static int
compare_iowrite(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;
	long dummy, oup1, oup2;

	(void) get_io_stats(p1, &dummy, &oup1, &dummy, &dummy, &dummy);
	(void) get_io_stats(p2, &dummy, &oup2, &dummy, &dummy, &dummy);

	return (oup2 - oup1);
}

static int
compare_iofault(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;
	long dummy, flp1, flp2;

	(void) get_io_stats(p1, &dummy, &dummy, &flp1, &dummy, &dummy);
	(void) get_io_stats(p2, &dummy, &dummy, &flp2, &dummy, &dummy);

	return (flp2 - flp1);
}

static int
compare_vcsw(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;
	long dummy, flp1, flp2;

	(void) get_io_stats(p1, &dummy, &dummy, &dummy, &flp1, &dummy);
	(void) get_io_stats(p2, &dummy, &dummy, &dummy, &flp2, &dummy);

	return (flp2 - flp1);
}

static int
compare_ivcsw(const void *arg1, const void *arg2)
{
	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;
	long dummy, flp1, flp2;

	(void) get_io_stats(p1, &dummy, &dummy, &dummy, &dummy, &flp1);
	(void) get_io_stats(p2, &dummy, &dummy, &dummy, &dummy, &flp2);

	return (flp2 - flp1);
}

int (*compares[])(const void *arg1, const void *arg2) = {
	compare_cpu,
	compare_size,
	compare_res,
	compare_time,
	compare_prio,
	compare_threads,
	compare_iototal,
	compare_ioread,
	compare_iowrite,
	compare_iofault,
	compare_vcsw,
	compare_ivcsw,
	compare_jid,
	compare_swap,
	NULL
};


static int
swapmode(int *retavail, int *retfree)
{
	int n;
	struct kvm_swap swapary[1];
	static int pagesize = 0;
	static unsigned long swap_maxpages = 0;

	*retavail = 0;
	*retfree = 0;

#define CONVERT(v)	((quad_t)(v) * pagesize / 1024)

	n = kvm_getswapinfo(kd, swapary, 1, 0);
	if (n < 0 || swapary[0].ksw_total == 0)
		return (0);

	if (pagesize == 0)
		pagesize = getpagesize();
	if (swap_maxpages == 0)
		GETSYSCTL("vm.swap_maxpages", swap_maxpages);

	/* ksw_total contains the total size of swap all devices which may
	   exceed the maximum swap size allocatable in the system */
	if ( swapary[0].ksw_total > swap_maxpages )
		swapary[0].ksw_total = swap_maxpages;

	*retavail = CONVERT(swapary[0].ksw_total);
	*retfree = CONVERT(swapary[0].ksw_total - swapary[0].ksw_used);

#undef CONVERT

	n = (int)(swapary[0].ksw_used * 100.0 / swapary[0].ksw_total);
	return (n);
}