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

/*
 * Copyright (c) 1982 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *	@(#)vm_meter.c	6.7 (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);
			goto loop;
		}
		continue;
	}

	/*
	 * No one wants in, so nothing to do.
	 */
	if (outpri == -20000) {
		(void) splhigh();
		if (wantin) {
			wantin = 0;
			sleep((caddr_t)&lbolt, PSWP);
		} else {
			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);
		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) {
			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)
					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 KM	1	/*
	2	* Copyright (c) 1982 Regents of the University of California.
	3	* All rights reserved. The Berkeley software License Agreement
	4	* specifies the terms and conditions for redistribution.
	5	*
	6	* @(#)vm_meter.c 6.7 (Berkeley) %G%
	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
e3bf9f41	20	int maxslp = MAXSLP;
e3bf9f41	21	int saferss = SAFERSS;
27b135c8 BJ	22
	23	/*
	24	* The following parameters control operation of the page replacement
	25	* algorithm. They are initialized to 0, and then computed at boot time
	26	* based on the size of the system. If they are patched non-zero in
	27	* a loaded vmunix they are left alone and may thus be changed per system
	28	* using adb on the loaded system.
	29	*/
	30	int maxpgio = 0;
	31	int minfree = 0;
	32	int desfree = 0;
	33	int lotsfree = 0;
	34	int slowscan = 0;
	35	int fastscan = 0;
e3bf9f41	36	int klin = KLIN;
27b135c8	37	int klseql = KLSEQL;
4643e8eb	38	int klsdist = KLSDIST;
27b135c8	39	int kltxt = KLTXT;
e3bf9f41 BJ	40	int klout = KLOUT;
	41	int multprog = -1; /* so we don't count process 2 */
	42
	43	double avenrun[3]; /* load average, of runnable procs */
	44
	45	/*
	46	* The main loop of the scheduling (swapping) process.
	47	*
	48	* The basic idea is:
	49	* see if anyone wants to be swapped in;
	50	* swap out processes until there is room;
	51	* swap him in;
	52	* repeat.
	53	* If the paging rate is too high, or the average free memory
	54	* is very low, then we do not consider swapping anyone in,
	55	* but rather look for someone to swap out.
	56	*
	57	* The runout flag is set whenever someone is swapped out.
	58	* Sched sleeps on it awaiting work.
	59	*
	60	* Sched sleeps on runin whenever it cannot find enough
	61	* core (by swapping out or otherwise) to fit the
	62	* selected swapped process. It is awakened when the
	63	* core situation changes and in any case once per second.
	64	*
	65	* sched DOESN'T ACCOUNT FOR PAGE TABLE SIZE IN CALCULATIONS.
	66	*/
	67
	68	#define swappable(p) \
	69	(((p)->p_flag&(SSYS\|SLOCK\|SULOCK\|SLOAD\|SPAGE\|SKEEP\|SWEXIT\|SPHYSIO))==SLOAD)
	70
	71	/* insure non-zero */
	72	#define nz(x) (x != 0 ? x : 1)
	73
	74	#define NBIG 4
	75	#define MAXNBIG 10
	76	int nbig = NBIG;
	77
	78	struct bigp {
	79	struct proc *bp_proc;
	80	int bp_pri;
	81	struct bigp *bp_link;
	82	} bigp[MAXNBIG], bplist;
	83
	84	sched()
	85	{
	86	register struct proc rp, p, *inp;
	87	int outpri, inpri, rppri;
97afa637	88	int sleeper, desperate, deservin, needs, divisor;
e3bf9f41 BJ	89	register struct bigp bp, nbp;
	90	int biggot, gives;
	91
e3bf9f41	92	loop:
7eb2e67e	93	wantin = 0;
e3bf9f41 BJ	94	deservin = 0;
	95	sleeper = 0;
	96	p = 0;
27b135c8	97	/*
37324218	98	* See if paging system is overloaded; if so swap someone out.
27b135c8 BJ	99	* Conditions for hard outswap are:
	100	* if need kernel map (mix it up).
	101	* or
	102	* 1. if there are at least 2 runnable processes (on the average)
	103	* and 2. the paging rate is excessive or memory is now VERY low.
	104	* and 3. the short (5-second) and longer (30-second) average
	105	* memory is less than desirable.
	106	*/
f3d75589 SL	107	if (kmapwnt \|\|
f3d75589 SL	108	(avenrun[0] >= 2 && imax(avefree, avefree30) < desfree &&
e3bf9f41	109	(rate.v_pgin + rate.v_pgout > maxpgio \|\| avefree < minfree))) {
97afa637	110	desperate = 1;
e3bf9f41 BJ	111	goto hardswap;
e3bf9f41 BJ	112	}
97afa637	113	desperate = 0;
e3bf9f41	114	/*
97afa637	115	* Not desperate for core,
e3bf9f41 BJ	116	* look for someone who deserves to be brought in.
	117	*/
	118	outpri = -20000;
1d348849	119	for (rp = allproc; rp != NULL; rp = rp->p_nxt) switch(rp->p_stat) {
e3bf9f41 BJ	120
	121	case SRUN:
	122	if ((rp->p_flag&SLOAD) == 0) {
27b135c8 BJ	123	rppri = rp->p_time -
27b135c8 BJ	124	rp->p_swrss / nz((maxpgio/2) * (klin * CLSIZE)) +
293c7069	125	rp->p_slptime - (rp->p_nice-NZERO)*8;
e3bf9f41 BJ	126	if (rppri > outpri) {
	127	if (rp->p_poip)
	128	continue;
	129	if (rp->p_textp && rp->p_textp->x_poip)
	130	continue;
	131	p = rp;
	132	outpri = rppri;
	133	}
	134	}
	135	continue;
	136
	137	case SSLEEP:
	138	case SSTOP:
	139	if ((freemem < desfree \|\| rp->p_rssize == 0) &&
	140	rp->p_slptime > maxslp &&
	141	(!rp->p_textp \|\| (rp->p_textp->x_flag&XLOCK)==0) &&
	142	swappable(rp)) {
	143	/*
	144	* Kick out deadwood.
e3bf9f41 BJ	145	*/
e3bf9f41 BJ	146	rp->p_flag &= ~SLOAD;
e650efcf	147	(void) swapout(rp, rp->p_dsize, rp->p_ssize);
e3bf9f41 BJ	148	goto loop;
	149	}
	150	continue;
	151	}
	152
	153	/*
	154	* No one wants in, so nothing to do.
	155	*/
	156	if (outpri == -20000) {
7d1e298f	157	(void) splhigh();
7eb2e67e BJ	158	if (wantin) {
	159	wantin = 0;
	160	sleep((caddr_t)&lbolt, PSWP);
	161	} else {
	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);
	281	goto loop;
	282	}
	283	/*
	284	* Want to swap someone in, but can't
	285	* so wait on runin.
	286	*/
7d1e298f	287	(void) splhigh();
e3bf9f41 BJ	288	runin++;
e3bf9f41 BJ	289	sleep((caddr_t)&runin, PSWP);
7eb2e67e	290	(void) spl0();
e3bf9f41 BJ	291	goto loop;
	292	}
	293
	294	vmmeter()
	295	{
	296	register unsigned cp, rp, *sp;
	297
27b135c8 BJ	298	deficit -= imin(deficit,
27b135c8 BJ	299	imax(deficit / 10, ((klin * CLSIZE) / 2) * maxpgio / 2));
e3bf9f41	300	ave(avefree, freemem, 5);
27b135c8	301	ave(avefree30, freemem, 30);
e3bf9f41 BJ	302	/* v_pgin is maintained by clock.c */
	303	cp = &cnt.v_first; rp = &rate.v_first; sp = &sum.v_first;
	304	while (cp <= &cnt.v_last) {
	305	ave(rp, cp, 5);
	306	sp += cp;
	307	*cp = 0;
	308	rp++, cp++, sp++;
	309	}
c4206698	310	if (time.tv_sec % 5 == 0) {
e3bf9f41 BJ	311	vmtotal();
	312	rate.v_swpin = cnt.v_swpin;
	313	sum.v_swpin += cnt.v_swpin;
	314	cnt.v_swpin = 0;
	315	rate.v_swpout = cnt.v_swpout;
	316	sum.v_swpout += cnt.v_swpout;
	317	cnt.v_swpout = 0;
	318	}
	319	if (avefree < minfree && runout \|\| proc[0].p_slptime > maxslp/2) {
	320	runout = 0;
	321	runin = 0;
	322	wakeup((caddr_t)&runin);
	323	wakeup((caddr_t)&runout);
	324	}
	325	}
	326
c4206698 BJ	327	/*
	328	* Schedule rate for paging.
	329	* Rate is linear interpolation between
	330	* slowscan with lotsfree and fastscan when out of memory.
	331	*/
	332	schedpaging()
e3bf9f41	333	{
a2faae5d	334	register int vavail;
e3bf9f41	335
e3bf9f41 BJ	336	nscan = desscan = 0;
	337	vavail = freemem - deficit;
	338	if (vavail < 0)
	339	vavail = 0;
e4d539fa	340	if (freemem < lotsfree) {
a2faae5d KM	341	desscan = (slowscan * vavail + fastscan * (lotsfree - vavail)) /
a2faae5d KM	342	nz(lotsfree) / RATETOSCHEDPAGING;
e4d539fa SL	343	wakeup((caddr_t)&proc[2]);
e4d539fa SL	344	}
b32450f4	345	timeout(schedpaging, (caddr_t)0, hz / RATETOSCHEDPAGING);
e3bf9f41 BJ	346	}
	347
	348	vmtotal()
	349	{
	350	register struct proc *p;
	351	register struct text *xp;
	352	int nrun = 0;
	353
	354	total.t_vmtxt = 0;
	355	total.t_avmtxt = 0;
	356	total.t_rmtxt = 0;
	357	total.t_armtxt = 0;
fcb2d36b	358	for (xp = text; xp < textNTEXT; xp++)
e3bf9f41 BJ	359	if (xp->x_iptr) {
	360	total.t_vmtxt += xp->x_size;
	361	total.t_rmtxt += xp->x_rssize;
	362	for (p = xp->x_caddr; p; p = p->p_xlink)
	363	switch (p->p_stat) {
	364
	365	case SSTOP:
	366	case SSLEEP:
	367	if (p->p_slptime >= maxslp)
	368	continue;
	369	/* fall into... */
	370
	371	case SRUN:
	372	case SIDL:
	373	total.t_avmtxt += xp->x_size;
	374	total.t_armtxt += xp->x_rssize;
	375	goto next;
	376	}
	377	next:
	378	;
	379	}
	380	total.t_vm = 0;
	381	total.t_avm = 0;
	382	total.t_rm = 0;
	383	total.t_arm = 0;
	384	total.t_rq = 0;
	385	total.t_dw = 0;
	386	total.t_pw = 0;
	387	total.t_sl = 0;
	388	total.t_sw = 0;
1d348849	389	for (p = allproc; p != NULL; p = p->p_nxt) {
e3bf9f41 BJ	390	if (p->p_flag & SSYS)
	391	continue;
	392	if (p->p_stat) {
	393	total.t_vm += p->p_dsize + p->p_ssize;
	394	total.t_rm += p->p_rssize;
	395	switch (p->p_stat) {
	396
	397	case SSLEEP:
	398	case SSTOP:
89b899a0	399	if (p->p_pri <= PZERO)
e3bf9f41 BJ	400	nrun++;
	401	if (p->p_flag & SPAGE)
	402	total.t_pw++;
	403	else if (p->p_flag & SLOAD) {
89b899a0	404	if (p->p_pri <= PZERO)
e3bf9f41 BJ	405	total.t_dw++;
	406	else if (p->p_slptime < maxslp)
	407	total.t_sl++;
	408	} else if (p->p_slptime < maxslp)
	409	total.t_sw++;
	410	if (p->p_slptime < maxslp)
	411	goto active;
	412	break;
	413
	414	case SRUN:
	415	case SIDL:
	416	nrun++;
	417	if (p->p_flag & SLOAD)
	418	total.t_rq++;
	419	else
	420	total.t_sw++;
	421	active:
	422	total.t_avm += p->p_dsize + p->p_ssize;
	423	total.t_arm += p->p_rssize;
	424	break;
	425	}
	426	}
	427	}
	428	total.t_vm += total.t_vmtxt;
	429	total.t_avm += total.t_avmtxt;
	430	total.t_rm += total.t_rmtxt;
	431	total.t_arm += total.t_armtxt;
	432	total.t_free = avefree;
	433	loadav(avenrun, nrun);
	434	}
	435
	436	/*
	437	* Constants for averages over 1, 5, and 15 minutes
	438	* when sampling at 5 second intervals.
	439	*/
	440	double cexp[3] = {
	441	0.9200444146293232, /* exp(-1/12) */
	442	0.9834714538216174, /* exp(-1/60) */
	443	0.9944598480048967, /* exp(-1/180) */
	444	};
	445
	446	/*
	447	* Compute a tenex style load average of a quantity on
	448	* 1, 5 and 15 minute intervals.
	449	*/
	450	loadav(avg, n)
	451	register double *avg;
	452	int n;
	453	{
	454	register int i;
	455
	456	for (i = 0; i < 3; i++)
	457	avg[i] = cexp[i] * avg[i] + n * (1.0 - cexp[i]);
	458	}