[unix-history] / usr / src / sys / vm / vm_meter.c

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *	@(#)vm_meter.c	7.4 (Berkeley) %G%
 */

#include "param.h"
#include "systm.h"
#include "seg.h"
#include "dir.h"
#include "user.h"
#include "proc.h"
#include "text.h"
#include "vm.h"
#include "cmap.h"
#include "kernel.h"


int	maxslp = MAXSLP;
int	saferss = SAFERSS;

/*
 * The following parameters control operation of the page replacement
 * algorithm.  They are initialized to 0, and then computed at boot time
 * based on the size of the system.  If they are patched non-zero in
 * a loaded vmunix they are left alone and may thus be changed per system
 * using adb on the loaded system.
 */
int	maxpgio = 0;
int	minfree = 0;
int	desfree = 0;
int	lotsfree = 0;
int	slowscan = 0;
int	fastscan = 0;
int	klin = KLIN;
int	klseql = KLSEQL;
int	klsdist = KLSDIST;
int	kltxt = KLTXT;
int	klout = KLOUT;
int	multprog = -1;		/* so we don't count process 2 */

double	avenrun[3];		/* load average, of runnable procs */

/*
 * The main loop of the scheduling (swapping) process.
 *
 * The basic idea is:
 *	see if anyone wants to be swapped in;
 *	swap out processes until there is room;
 *	swap him in;
 *	repeat.
 * If the paging rate is too high, or the average free memory
 * is very low, then we do not consider swapping anyone in,
 * but rather look for someone to swap out.
 *
 * The runout flag is set whenever someone is swapped out.
 * Sched sleeps on it awaiting work.
 *
 * Sched sleeps on runin whenever it cannot find enough
 * core (by swapping out or otherwise) to fit the
 * selected swapped process.  It is awakened when the
 * core situation changes and in any case once per second.
 *
 * sched DOESN'T ACCOUNT FOR PAGE TABLE SIZE IN CALCULATIONS.
 */

#define	swappable(p) \
	(((p)->p_flag&(SSYS|SLOCK|SULOCK|SLOAD|SPAGE|SKEEP|SWEXIT|SPHYSIO))==SLOAD)

/* insure non-zero */
#define	nz(x)	(x != 0 ? x : 1)

#define	NBIG	4
#define	MAXNBIG	10
int	nbig = NBIG;

struct bigp {
	struct	proc *bp_proc;
	int	bp_pri;
	struct	bigp *bp_link;
} bigp[MAXNBIG], bplist;

sched()
{
	register struct proc *rp, *p, *inp;
	int outpri, inpri, rppri;
	int sleeper, desperate, deservin, needs, divisor;
	register struct bigp *bp, *nbp;
	int biggot, gives;

loop:
	wantin = 0;
	deservin = 0;
	sleeper = 0;
	p = 0;
	/*
	 * See if paging system is overloaded; if so swap someone out.
	 * Conditions for hard outswap are:
	 *	if need kernel map (mix it up).
	 * or
	 *	1. if there are at least 2 runnable processes (on the average)
	 * and	2. the paging rate is excessive or memory is now VERY low.
	 * and	3. the short (5-second) and longer (30-second) average
	 *	   memory is less than desirable.
	 */
	if (kmapwnt ||
	    (avenrun[0] >= 2 && imax(avefree, avefree30) < desfree &&
	    (rate.v_pgin + rate.v_pgout > maxpgio || avefree < minfree))) {
		desperate = 1;
		goto hardswap;
	}
	desperate = 0;
	/*
	 * Not desperate for core,
	 * look for someone who deserves to be brought in.
	 */
	outpri = -20000;
	for (rp = allproc; rp != NULL; rp = rp->p_nxt) switch(rp->p_stat) {

	case SRUN:
		if ((rp->p_flag&SLOAD) == 0) {
			rppri = rp->p_time -
			    rp->p_swrss / nz((maxpgio/2) * (klin * CLSIZE)) +
			    rp->p_slptime - (rp->p_nice-NZERO)*8;
			if (rppri > outpri) {
				if (rp->p_poip)
					continue;
				if (rp->p_textp && rp->p_textp->x_poip)
					continue;
				p = rp;
				outpri = rppri;
			}
		}
		continue;

	case SSLEEP:
	case SSTOP:
		if ((freemem < desfree || rp->p_rssize == 0) &&
		    rp->p_slptime > maxslp &&
		    (!rp->p_textp || (rp->p_textp->x_flag&XLOCK)==0) &&
		    swappable(rp)) {
			/*
			 * Kick out deadwood.
			 */
			rp->p_flag &= ~SLOAD;
			(void) swapout(rp, rp->p_dsize, rp->p_ssize);
		}
		continue;
	}

	/*
	 * If something came ready after we checked it,
	 * wantin will be set.  Otherwise,
	 * no one wants in, so nothing to do.
	 */
	if (outpri == -20000) {
		(void) splhigh();
		if (wantin == 0) {
			runout++;
			sleep((caddr_t)&runout, PSWP);
		}
		(void) spl0();
		goto loop;
	}
	/*
	 * Decide how deserving this guy is.  If he is deserving
	 * we will be willing to work harder to bring him in.
	 * Needs is an estimate of how much core he will need.
	 * If he has been out for a while, then we will
	 * bring him in with 1/2 the core he will need, otherwise
	 * we are conservative.
	 */
	deservin = 0;
	divisor = 1;
	if (outpri > maxslp/2) {
		deservin = 1;
		divisor = 2;
	}
	needs = p->p_swrss;
	if (p->p_textp && p->p_textp->x_ccount == 0)
		needs += p->p_textp->x_swrss;
	needs = imin(needs, lotsfree);
	if (freemem - deficit > needs / divisor) {
		deficit += needs;
		if (swapin(p))
			goto loop;
		deficit -= imin(needs, deficit);
	}

hardswap:
	/*
	 * Need resources (kernel map or memory), swap someone out.
	 * Select the nbig largest jobs, then the oldest of these
	 * is ``most likely to get booted.''
	 */
	inp = p;
	sleeper = 0;
	if (nbig > MAXNBIG)
		nbig = MAXNBIG;
	if (nbig < 1)
		nbig = 1;
	biggot = 0;
	bplist.bp_link = 0;
	for (rp = allproc; rp != NULL; rp = rp->p_nxt) {
		if (!swappable(rp))
			continue;
		if (rp == inp)
			continue;
		if (rp->p_textp && rp->p_textp->x_flag&XLOCK)
			continue;
		if (rp->p_slptime > maxslp &&
		    (rp->p_stat==SSLEEP&&rp->p_pri>PZERO||rp->p_stat==SSTOP)) {
			if (sleeper < rp->p_slptime) {
				p = rp;
				sleeper = rp->p_slptime;
			}
		} else if (!sleeper && (rp->p_stat==SRUN||rp->p_stat==SSLEEP)) {
			rppri = rp->p_rssize;
			if (rp->p_textp)
				rppri += rp->p_textp->x_rssize/rp->p_textp->x_ccount;
			if (biggot < nbig)
				nbp = &bigp[biggot++];
			else {
				nbp = bplist.bp_link;
				if (nbp->bp_pri > rppri)
					continue;
				bplist.bp_link = nbp->bp_link;
			}
			for (bp = &bplist; bp->bp_link; bp = bp->bp_link)
				if (rppri < bp->bp_link->bp_pri)
					break;
			nbp->bp_link = bp->bp_link;
			bp->bp_link = nbp;
			nbp->bp_pri = rppri;
			nbp->bp_proc = rp;
		}
	}
	if (!sleeper) {
		p = NULL;
		inpri = -1000;
		for (bp = bplist.bp_link; bp; bp = bp->bp_link) {
			rp = bp->bp_proc;
			rppri = rp->p_time+rp->p_nice-NZERO;
			if (rppri >= inpri) {
				p = rp;
				inpri = rppri;
			}
		}
	}
	/*
	 * If we found a long-time sleeper, or we are desperate and
	 * found anyone to swap out, or if someone deserves to come
	 * in and we didn't find a sleeper, but found someone who
	 * has been in core for a reasonable length of time, then
	 * we kick the poor luser out.
	 */
	if (sleeper || desperate && p || deservin && inpri > maxslp) {
		(void) splhigh();
		p->p_flag &= ~SLOAD;
		if (p->p_stat == SRUN)
			remrq(p);
		(void) spl0();
		if (desperate) {
			/*
			 * Want to give this space to the rest of
			 * the processes in core so give them a chance
			 * by increasing the deficit.
			 */
			gives = p->p_rssize;
			if (p->p_textp)
				gives += p->p_textp->x_rssize / p->p_textp->x_ccount;
			gives = imin(gives, lotsfree);
			deficit += gives;
		} else
			gives = 0;	/* someone else taketh away */
		if (swapout(p, p->p_dsize, p->p_ssize) == 0)
			deficit -= imin(gives, deficit);
		else
			goto loop;
	}
	/*
	 * Want to swap someone in, but can't
	 * so wait on runin.
	 */
	(void) splhigh();
	runin++;
	sleep((caddr_t)&runin, PSWP);
	(void) spl0();
	goto loop;
}

vmmeter()
{
	register unsigned *cp, *rp, *sp;

	deficit -= imin(deficit,
	    imax(deficit / 10, ((klin * CLSIZE) / 2) * maxpgio / 2));
	ave(avefree, freemem, 5);
	ave(avefree30, freemem, 30);
	/* v_pgin is maintained by clock.c */
	cp = &cnt.v_first; rp = &rate.v_first; sp = &sum.v_first;
	while (cp <= &cnt.v_last) {
		ave(*rp, *cp, 5);
		*sp += *cp;
		*cp = 0;
		rp++, cp++, sp++;
	}
	if (time.tv_sec % 5 == 0) {
		vmtotal();
		rate.v_swpin = cnt.v_swpin;
		sum.v_swpin += cnt.v_swpin;
		cnt.v_swpin = 0;
		rate.v_swpout = cnt.v_swpout;
		sum.v_swpout += cnt.v_swpout;
		cnt.v_swpout = 0;
	}
	if (avefree < minfree && runout || proc[0].p_slptime > maxslp/2) {
		runout = 0;
		runin = 0;
		wakeup((caddr_t)&runin);
		wakeup((caddr_t)&runout);
	}
}

/*
 * Schedule rate for paging.
 * Rate is linear interpolation between
 * slowscan with lotsfree and fastscan when out of memory.
 */
schedpaging()
{
	register int vavail;

	nscan = desscan = 0;
	vavail = freemem - deficit;
	if (vavail < 0)
		vavail = 0;
	if (freemem < lotsfree) {
		desscan = (slowscan * vavail + fastscan * (lotsfree - vavail)) /
			nz(lotsfree) / RATETOSCHEDPAGING;
		wakeup((caddr_t)&proc[2]);
	}
	timeout(schedpaging, (caddr_t)0, hz / RATETOSCHEDPAGING);
}

vmtotal()
{
	register struct proc *p;
	register struct text *xp;
	int nrun = 0;

	total.t_vmtxt = 0;
	total.t_avmtxt = 0;
	total.t_rmtxt = 0;
	total.t_armtxt = 0;
	for (xp = text; xp < textNTEXT; xp++)
		if (xp->x_iptr) {
			total.t_vmtxt += xp->x_size;
			total.t_rmtxt += xp->x_rssize;
			for (p = xp->x_caddr; p; p = p->p_xlink)
			switch (p->p_stat) {

			case SSTOP:
			case SSLEEP:
				if (p->p_slptime >= maxslp)
					continue;
				/* fall into... */

			case SRUN:
			case SIDL:
				total.t_avmtxt += xp->x_size;
				total.t_armtxt += xp->x_rssize;
				goto next;
			}
next:
			;
		}
	total.t_vm = 0;
	total.t_avm = 0;
	total.t_rm = 0;
	total.t_arm = 0;
	total.t_rq = 0;
	total.t_dw = 0;
	total.t_pw = 0;
	total.t_sl = 0;
	total.t_sw = 0;
	for (p = allproc; p != NULL; p = p->p_nxt) {
		if (p->p_flag & SSYS)
			continue;
		if (p->p_stat) {
			if (p->p_stat != SZOMB) {
				total.t_vm += p->p_dsize + p->p_ssize;
				total.t_rm += p->p_rssize;
			}
			switch (p->p_stat) {

			case SSLEEP:
			case SSTOP:
				if (p->p_pri <= PZERO && p->p_stat == SSLEEP)
					nrun++;
				if (p->p_flag & SPAGE)
					total.t_pw++;
				else if (p->p_flag & SLOAD) {
					if (p->p_pri <= PZERO)
						total.t_dw++;
					else if (p->p_slptime < maxslp)
						total.t_sl++;
				} else if (p->p_slptime < maxslp)
					total.t_sw++;
				if (p->p_slptime < maxslp)
					goto active;
				break;

			case SRUN:
			case SIDL:
				nrun++;
				if (p->p_flag & SLOAD)
					total.t_rq++;
				else
					total.t_sw++;
active:
				total.t_avm += p->p_dsize + p->p_ssize;
				total.t_arm += p->p_rssize;
				break;
			}
		}
	}
	total.t_vm += total.t_vmtxt;
	total.t_avm += total.t_avmtxt;
	total.t_rm += total.t_rmtxt;
	total.t_arm += total.t_armtxt;
	total.t_free = avefree;
	loadav(avenrun, nrun);
}

/*
 * Constants for averages over 1, 5, and 15 minutes
 * when sampling at 5 second intervals.
 */
double	cexp[3] = {
	0.9200444146293232,	/* exp(-1/12) */
	0.9834714538216174,	/* exp(-1/60) */
	0.9944598480048967,	/* exp(-1/180) */
};

/*
 * Compute a tenex style load average of a quantity on
 * 1, 5 and 15 minute intervals.
 */
loadav(avg, n)
	register double *avg;
	int n;
{
	register int i;

	for (i = 0; i < 3; i++)
		avg[i] = cexp[i] * avg[i] + n * (1.0 - cexp[i]);
}
Commit	Line	Data
da7c5cc6	1	/*
0880b18e	2	* Copyright (c) 1982, 1986 Regents of the University of California.
da7c5cc6 KM	3	* All rights reserved. The Berkeley software License Agreement
	4	* specifies the terms and conditions for redistribution.
	5	*
255473d5	6	* @(#)vm_meter.c 7.4 (Berkeley) %G%
da7c5cc6	7	*/
e3bf9f41	8
94368568 JB	9	#include "param.h"
	10	#include "systm.h"
	11	#include "seg.h"
	12	#include "dir.h"
	13	#include "user.h"
	14	#include "proc.h"
	15	#include "text.h"
	16	#include "vm.h"
	17	#include "cmap.h"
	18	#include "kernel.h"
e3bf9f41	19
69880c73 MK	20
69880c73 MK	21
e3bf9f41	22	int maxslp = MAXSLP;
e3bf9f41	23	int saferss = SAFERSS;
27b135c8 BJ	24
	25	/*
	26	* The following parameters control operation of the page replacement
	27	* algorithm. They are initialized to 0, and then computed at boot time
	28	* based on the size of the system. If they are patched non-zero in
	29	* a loaded vmunix they are left alone and may thus be changed per system
	30	* using adb on the loaded system.
	31	*/
	32	int maxpgio = 0;
	33	int minfree = 0;
	34	int desfree = 0;
	35	int lotsfree = 0;
	36	int slowscan = 0;
	37	int fastscan = 0;
e3bf9f41	38	int klin = KLIN;
27b135c8	39	int klseql = KLSEQL;
4643e8eb	40	int klsdist = KLSDIST;
27b135c8	41	int kltxt = KLTXT;
e3bf9f41 BJ	42	int klout = KLOUT;
	43	int multprog = -1; /* so we don't count process 2 */
	44
	45	double avenrun[3]; /* load average, of runnable procs */
	46
	47	/*
	48	* The main loop of the scheduling (swapping) process.
	49	*
	50	* The basic idea is:
	51	* see if anyone wants to be swapped in;
	52	* swap out processes until there is room;
	53	* swap him in;
	54	* repeat.
	55	* If the paging rate is too high, or the average free memory
	56	* is very low, then we do not consider swapping anyone in,
	57	* but rather look for someone to swap out.
	58	*
	59	* The runout flag is set whenever someone is swapped out.
	60	* Sched sleeps on it awaiting work.
	61	*
	62	* Sched sleeps on runin whenever it cannot find enough
	63	* core (by swapping out or otherwise) to fit the
	64	* selected swapped process. It is awakened when the
	65	* core situation changes and in any case once per second.
	66	*
	67	* sched DOESN'T ACCOUNT FOR PAGE TABLE SIZE IN CALCULATIONS.
	68	*/
	69
	70	#define swappable(p) \
	71	(((p)->p_flag&(SSYS\|SLOCK\|SULOCK\|SLOAD\|SPAGE\|SKEEP\|SWEXIT\|SPHYSIO))==SLOAD)
	72
	73	/* insure non-zero */
	74	#define nz(x) (x != 0 ? x : 1)
	75
	76	#define NBIG 4
	77	#define MAXNBIG 10
	78	int nbig = NBIG;
	79
	80	struct bigp {
	81	struct proc *bp_proc;
	82	int bp_pri;
	83	struct bigp *bp_link;
	84	} bigp[MAXNBIG], bplist;
	85
	86	sched()
	87	{
	88	register struct proc rp, p, *inp;
	89	int outpri, inpri, rppri;
97afa637	90	int sleeper, desperate, deservin, needs, divisor;
e3bf9f41 BJ	91	register struct bigp bp, nbp;
	92	int biggot, gives;
	93
e3bf9f41	94	loop:
7eb2e67e	95	wantin = 0;
e3bf9f41 BJ	96	deservin = 0;
	97	sleeper = 0;
	98	p = 0;
27b135c8	99	/*
37324218	100	* See if paging system is overloaded; if so swap someone out.
27b135c8 BJ	101	* Conditions for hard outswap are:
	102	* if need kernel map (mix it up).
	103	* or
	104	* 1. if there are at least 2 runnable processes (on the average)
	105	* and 2. the paging rate is excessive or memory is now VERY low.
	106	* and 3. the short (5-second) and longer (30-second) average
	107	* memory is less than desirable.
	108	*/
f3d75589 SL	109	if (kmapwnt \|\|
f3d75589 SL	110	(avenrun[0] >= 2 && imax(avefree, avefree30) < desfree &&
e3bf9f41	111	(rate.v_pgin + rate.v_pgout > maxpgio \|\| avefree < minfree))) {
97afa637	112	desperate = 1;
e3bf9f41 BJ	113	goto hardswap;
e3bf9f41 BJ	114	}
97afa637	115	desperate = 0;
e3bf9f41	116	/*
97afa637	117	* Not desperate for core,
e3bf9f41 BJ	118	* look for someone who deserves to be brought in.
	119	*/
	120	outpri = -20000;
1d348849	121	for (rp = allproc; rp != NULL; rp = rp->p_nxt) switch(rp->p_stat) {
e3bf9f41 BJ	122
	123	case SRUN:
	124	if ((rp->p_flag&SLOAD) == 0) {
27b135c8 BJ	125	rppri = rp->p_time -
27b135c8 BJ	126	rp->p_swrss / nz((maxpgio/2) * (klin * CLSIZE)) +
293c7069	127	rp->p_slptime - (rp->p_nice-NZERO)*8;
e3bf9f41 BJ	128	if (rppri > outpri) {
	129	if (rp->p_poip)
	130	continue;
	131	if (rp->p_textp && rp->p_textp->x_poip)
	132	continue;
	133	p = rp;
	134	outpri = rppri;
	135	}
	136	}
	137	continue;
	138
	139	case SSLEEP:
	140	case SSTOP:
	141	if ((freemem < desfree \|\| rp->p_rssize == 0) &&
	142	rp->p_slptime > maxslp &&
	143	(!rp->p_textp \|\| (rp->p_textp->x_flag&XLOCK)==0) &&
	144	swappable(rp)) {
	145	/*
	146	* Kick out deadwood.
e3bf9f41 BJ	147	*/
e3bf9f41 BJ	148	rp->p_flag &= ~SLOAD;
e650efcf	149	(void) swapout(rp, rp->p_dsize, rp->p_ssize);
e3bf9f41 BJ	150	}
	151	continue;
	152	}
	153
	154	/*
255473d5 MK	155	* If something came ready after we checked it,
	156	* wantin will be set. Otherwise,
	157	* no one wants in, so nothing to do.
e3bf9f41 BJ	158	*/
e3bf9f41 BJ	159	if (outpri == -20000) {
7d1e298f	160	(void) splhigh();
255473d5	161	if (wantin == 0) {
7eb2e67e BJ	162	runout++;
	163	sleep((caddr_t)&runout, PSWP);
	164	}
	165	(void) spl0();
e3bf9f41 BJ	166	goto loop;
e3bf9f41 BJ	167	}
e3bf9f41 BJ	168	/*
	169	* Decide how deserving this guy is. If he is deserving
	170	* we will be willing to work harder to bring him in.
	171	* Needs is an estimate of how much core he will need.
	172	* If he has been out for a while, then we will
	173	* bring him in with 1/2 the core he will need, otherwise
	174	* we are conservative.
	175	*/
	176	deservin = 0;
	177	divisor = 1;
	178	if (outpri > maxslp/2) {
	179	deservin = 1;
	180	divisor = 2;
	181	}
	182	needs = p->p_swrss;
	183	if (p->p_textp && p->p_textp->x_ccount == 0)
	184	needs += p->p_textp->x_swrss;
27b135c8	185	needs = imin(needs, lotsfree);
e3bf9f41 BJ	186	if (freemem - deficit > needs / divisor) {
	187	deficit += needs;
	188	if (swapin(p))
	189	goto loop;
	190	deficit -= imin(needs, deficit);
	191	}
	192
	193	hardswap:
	194	/*
	195	* Need resources (kernel map or memory), swap someone out.
	196	* Select the nbig largest jobs, then the oldest of these
	197	* is ``most likely to get booted.''
	198	*/
e3bf9f41 BJ	199	inp = p;
	200	sleeper = 0;
	201	if (nbig > MAXNBIG)
	202	nbig = MAXNBIG;
	203	if (nbig < 1)
	204	nbig = 1;
	205	biggot = 0;
	206	bplist.bp_link = 0;
1d348849	207	for (rp = allproc; rp != NULL; rp = rp->p_nxt) {
e3bf9f41 BJ	208	if (!swappable(rp))
e3bf9f41 BJ	209	continue;
e3bf9f41 BJ	210	if (rp == inp)
	211	continue;
	212	if (rp->p_textp && rp->p_textp->x_flag&XLOCK)
	213	continue;
	214	if (rp->p_slptime > maxslp &&
89b899a0	215	(rp->p_stat==SSLEEP&&rp->p_pri>PZERO\|\|rp->p_stat==SSTOP)) {
e3bf9f41 BJ	216	if (sleeper < rp->p_slptime) {
	217	p = rp;
	218	sleeper = rp->p_slptime;
	219	}
	220	} else if (!sleeper && (rp->p_stat==SRUN\|\|rp->p_stat==SSLEEP)) {
	221	rppri = rp->p_rssize;
	222	if (rp->p_textp)
293c7069	223	rppri += rp->p_textp->x_rssize/rp->p_textp->x_ccount;
e3bf9f41 BJ	224	if (biggot < nbig)
	225	nbp = &bigp[biggot++];
	226	else {
	227	nbp = bplist.bp_link;
	228	if (nbp->bp_pri > rppri)
	229	continue;
	230	bplist.bp_link = nbp->bp_link;
	231	}
	232	for (bp = &bplist; bp->bp_link; bp = bp->bp_link)
	233	if (rppri < bp->bp_link->bp_pri)
	234	break;
	235	nbp->bp_link = bp->bp_link;
	236	bp->bp_link = nbp;
	237	nbp->bp_pri = rppri;
	238	nbp->bp_proc = rp;
	239	}
	240	}
	241	if (!sleeper) {
	242	p = NULL;
	243	inpri = -1000;
	244	for (bp = bplist.bp_link; bp; bp = bp->bp_link) {
	245	rp = bp->bp_proc;
	246	rppri = rp->p_time+rp->p_nice-NZERO;
	247	if (rppri >= inpri) {
	248	p = rp;
	249	inpri = rppri;
	250	}
	251	}
	252	}
	253	/*
97afa637	254	* If we found a long-time sleeper, or we are desperate and
e3bf9f41 BJ	255	* found anyone to swap out, or if someone deserves to come
	256	* in and we didn't find a sleeper, but found someone who
	257	* has been in core for a reasonable length of time, then
	258	* we kick the poor luser out.
	259	*/
97afa637	260	if (sleeper \|\| desperate && p \|\| deservin && inpri > maxslp) {
7d1e298f	261	(void) splhigh();
e3bf9f41 BJ	262	p->p_flag &= ~SLOAD;
	263	if (p->p_stat == SRUN)
	264	remrq(p);
7eb2e67e	265	(void) spl0();
97afa637	266	if (desperate) {
e3bf9f41 BJ	267	/*
	268	* Want to give this space to the rest of
	269	* the processes in core so give them a chance
	270	* by increasing the deficit.
	271	*/
	272	gives = p->p_rssize;
	273	if (p->p_textp)
	274	gives += p->p_textp->x_rssize / p->p_textp->x_ccount;
9eec1cb0	275	gives = imin(gives, lotsfree);
e3bf9f41 BJ	276	deficit += gives;
	277	} else
	278	gives = 0; /* someone else taketh away */
	279	if (swapout(p, p->p_dsize, p->p_ssize) == 0)
	280	deficit -= imin(gives, deficit);
69880c73 MK	281	else
69880c73 MK	282	goto loop;
e3bf9f41 BJ	283	}
	284	/*
	285	* Want to swap someone in, but can't
	286	* so wait on runin.
	287	*/
7d1e298f	288	(void) splhigh();
e3bf9f41 BJ	289	runin++;
e3bf9f41 BJ	290	sleep((caddr_t)&runin, PSWP);
7eb2e67e	291	(void) spl0();
e3bf9f41 BJ	292	goto loop;
	293	}
	294
	295	vmmeter()
	296	{
	297	register unsigned cp, rp, *sp;
	298
27b135c8 BJ	299	deficit -= imin(deficit,
27b135c8 BJ	300	imax(deficit / 10, ((klin * CLSIZE) / 2) * maxpgio / 2));
e3bf9f41	301	ave(avefree, freemem, 5);
27b135c8	302	ave(avefree30, freemem, 30);
e3bf9f41 BJ	303	/* v_pgin is maintained by clock.c */
	304	cp = &cnt.v_first; rp = &rate.v_first; sp = &sum.v_first;
	305	while (cp <= &cnt.v_last) {
	306	ave(rp, cp, 5);
	307	sp += cp;
	308	*cp = 0;
	309	rp++, cp++, sp++;
	310	}
c4206698	311	if (time.tv_sec % 5 == 0) {
e3bf9f41 BJ	312	vmtotal();
	313	rate.v_swpin = cnt.v_swpin;
	314	sum.v_swpin += cnt.v_swpin;
	315	cnt.v_swpin = 0;
	316	rate.v_swpout = cnt.v_swpout;
	317	sum.v_swpout += cnt.v_swpout;
	318	cnt.v_swpout = 0;
	319	}
	320	if (avefree < minfree && runout \|\| proc[0].p_slptime > maxslp/2) {
	321	runout = 0;
	322	runin = 0;
	323	wakeup((caddr_t)&runin);
	324	wakeup((caddr_t)&runout);
	325	}
	326	}
	327
c4206698 BJ	328	/*
	329	* Schedule rate for paging.
	330	* Rate is linear interpolation between
	331	* slowscan with lotsfree and fastscan when out of memory.
	332	*/
	333	schedpaging()
e3bf9f41	334	{
a2faae5d	335	register int vavail;
e3bf9f41	336
e3bf9f41 BJ	337	nscan = desscan = 0;
	338	vavail = freemem - deficit;
	339	if (vavail < 0)
	340	vavail = 0;
e4d539fa	341	if (freemem < lotsfree) {
a2faae5d KM	342	desscan = (slowscan * vavail + fastscan * (lotsfree - vavail)) /
a2faae5d KM	343	nz(lotsfree) / RATETOSCHEDPAGING;
e4d539fa SL	344	wakeup((caddr_t)&proc[2]);
e4d539fa SL	345	}
b32450f4	346	timeout(schedpaging, (caddr_t)0, hz / RATETOSCHEDPAGING);
e3bf9f41 BJ	347	}
	348
	349	vmtotal()
	350	{
	351	register struct proc *p;
	352	register struct text *xp;
	353	int nrun = 0;
	354
	355	total.t_vmtxt = 0;
	356	total.t_avmtxt = 0;
	357	total.t_rmtxt = 0;
	358	total.t_armtxt = 0;
fcb2d36b	359	for (xp = text; xp < textNTEXT; xp++)
e3bf9f41 BJ	360	if (xp->x_iptr) {
	361	total.t_vmtxt += xp->x_size;
	362	total.t_rmtxt += xp->x_rssize;
	363	for (p = xp->x_caddr; p; p = p->p_xlink)
	364	switch (p->p_stat) {
	365
	366	case SSTOP:
	367	case SSLEEP:
	368	if (p->p_slptime >= maxslp)
	369	continue;
	370	/* fall into... */
	371
	372	case SRUN:
	373	case SIDL:
	374	total.t_avmtxt += xp->x_size;
	375	total.t_armtxt += xp->x_rssize;
	376	goto next;
	377	}
	378	next:
	379	;
	380	}
	381	total.t_vm = 0;
	382	total.t_avm = 0;
	383	total.t_rm = 0;
	384	total.t_arm = 0;
	385	total.t_rq = 0;
	386	total.t_dw = 0;
	387	total.t_pw = 0;
	388	total.t_sl = 0;
	389	total.t_sw = 0;
1d348849	390	for (p = allproc; p != NULL; p = p->p_nxt) {
e3bf9f41 BJ	391	if (p->p_flag & SSYS)
	392	continue;
	393	if (p->p_stat) {
9745e17d KB	394	if (p->p_stat != SZOMB) {
	395	total.t_vm += p->p_dsize + p->p_ssize;
	396	total.t_rm += p->p_rssize;
	397	}
e3bf9f41 BJ	398	switch (p->p_stat) {
	399
	400	case SSLEEP:
	401	case SSTOP:
f419aceb	402	if (p->p_pri <= PZERO && p->p_stat == SSLEEP)
e3bf9f41 BJ	403	nrun++;
	404	if (p->p_flag & SPAGE)
	405	total.t_pw++;
	406	else if (p->p_flag & SLOAD) {
89b899a0	407	if (p->p_pri <= PZERO)
e3bf9f41 BJ	408	total.t_dw++;
	409	else if (p->p_slptime < maxslp)
	410	total.t_sl++;
	411	} else if (p->p_slptime < maxslp)
	412	total.t_sw++;
	413	if (p->p_slptime < maxslp)
	414	goto active;
	415	break;
	416
	417	case SRUN:
	418	case SIDL:
	419	nrun++;
	420	if (p->p_flag & SLOAD)
	421	total.t_rq++;
	422	else
	423	total.t_sw++;
	424	active:
	425	total.t_avm += p->p_dsize + p->p_ssize;
	426	total.t_arm += p->p_rssize;
	427	break;
	428	}
	429	}
	430	}
	431	total.t_vm += total.t_vmtxt;
	432	total.t_avm += total.t_avmtxt;
	433	total.t_rm += total.t_rmtxt;
	434	total.t_arm += total.t_armtxt;
	435	total.t_free = avefree;
	436	loadav(avenrun, nrun);
	437	}
	438
	439	/*
	440	* Constants for averages over 1, 5, and 15 minutes
	441	* when sampling at 5 second intervals.
	442	*/
	443	double cexp[3] = {
	444	0.9200444146293232, /* exp(-1/12) */
	445	0.9834714538216174, /* exp(-1/60) */
	446	0.9944598480048967, /* exp(-1/180) */
	447	};
	448
	449	/*
	450	* Compute a tenex style load average of a quantity on
	451	* 1, 5 and 15 minute intervals.
	452	*/
	453	loadav(avg, n)
	454	register double *avg;
	455	int n;
	456	{
	457	register int i;
	458
	459	for (i = 0; i < 3; i++)
	460	avg[i] = cexp[i] * avg[i] + n * (1.0 - cexp[i]);
	461	}