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

/*	vm_meter.c	6.5	85/03/03	*/

#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.
			 */
			(void) spl6();
			rp->p_flag &= ~SLOAD;
			if (rp->p_stat == SRUN)
				remrq(rp);
			(void) spl0();
			(void) swapout(rp, rp->p_dsize, rp->p_ssize);
			goto loop;
		}
		continue;
	}

	/*
	 * No one wants in, so nothing to do.
	 */
	if (outpri == -20000) {
		(void) spl6();
		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) spl6();
		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) spl6();
	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
a2faae5d	1	/* vm_meter.c 6.5 85/03/03 */
e3bf9f41	2
94368568 JB	3	#include "param.h"
	4	#include "systm.h"
	5	#include "seg.h"
	6	#include "dir.h"
	7	#include "user.h"
	8	#include "proc.h"
	9	#include "text.h"
	10	#include "vm.h"
	11	#include "cmap.h"
	12	#include "kernel.h"
e3bf9f41	13
e3bf9f41	14	int maxslp = MAXSLP;
e3bf9f41	15	int saferss = SAFERSS;
27b135c8 BJ	16
	17	/*
	18	* The following parameters control operation of the page replacement
	19	* algorithm. They are initialized to 0, and then computed at boot time
	20	* based on the size of the system. If they are patched non-zero in
	21	* a loaded vmunix they are left alone and may thus be changed per system
	22	* using adb on the loaded system.
	23	*/
	24	int maxpgio = 0;
	25	int minfree = 0;
	26	int desfree = 0;
	27	int lotsfree = 0;
	28	int slowscan = 0;
	29	int fastscan = 0;
e3bf9f41	30	int klin = KLIN;
27b135c8	31	int klseql = KLSEQL;
4643e8eb	32	int klsdist = KLSDIST;
27b135c8	33	int kltxt = KLTXT;
e3bf9f41 BJ	34	int klout = KLOUT;
	35	int multprog = -1; /* so we don't count process 2 */
	36
	37	double avenrun[3]; /* load average, of runnable procs */
	38
	39	/*
	40	* The main loop of the scheduling (swapping) process.
	41	*
	42	* The basic idea is:
	43	* see if anyone wants to be swapped in;
	44	* swap out processes until there is room;
	45	* swap him in;
	46	* repeat.
	47	* If the paging rate is too high, or the average free memory
	48	* is very low, then we do not consider swapping anyone in,
	49	* but rather look for someone to swap out.
	50	*
	51	* The runout flag is set whenever someone is swapped out.
	52	* Sched sleeps on it awaiting work.
	53	*
	54	* Sched sleeps on runin whenever it cannot find enough
	55	* core (by swapping out or otherwise) to fit the
	56	* selected swapped process. It is awakened when the
	57	* core situation changes and in any case once per second.
	58	*
	59	* sched DOESN'T ACCOUNT FOR PAGE TABLE SIZE IN CALCULATIONS.
	60	*/
	61
	62	#define swappable(p) \
	63	(((p)->p_flag&(SSYS\|SLOCK\|SULOCK\|SLOAD\|SPAGE\|SKEEP\|SWEXIT\|SPHYSIO))==SLOAD)
	64
	65	/* insure non-zero */
	66	#define nz(x) (x != 0 ? x : 1)
	67
	68	#define NBIG 4
	69	#define MAXNBIG 10
	70	int nbig = NBIG;
	71
	72	struct bigp {
	73	struct proc *bp_proc;
	74	int bp_pri;
	75	struct bigp *bp_link;
	76	} bigp[MAXNBIG], bplist;
	77
	78	sched()
	79	{
	80	register struct proc rp, p, *inp;
	81	int outpri, inpri, rppri;
97afa637	82	int sleeper, desperate, deservin, needs, divisor;
e3bf9f41 BJ	83	register struct bigp bp, nbp;
	84	int biggot, gives;
	85
e3bf9f41	86	loop:
7eb2e67e	87	wantin = 0;
e3bf9f41 BJ	88	deservin = 0;
	89	sleeper = 0;
	90	p = 0;
27b135c8	91	/*
37324218	92	* See if paging system is overloaded; if so swap someone out.
27b135c8 BJ	93	* Conditions for hard outswap are:
	94	* if need kernel map (mix it up).
	95	* or
	96	* 1. if there are at least 2 runnable processes (on the average)
	97	* and 2. the paging rate is excessive or memory is now VERY low.
	98	* and 3. the short (5-second) and longer (30-second) average
	99	* memory is less than desirable.
	100	*/
f3d75589 SL	101	if (kmapwnt \|\|
f3d75589 SL	102	(avenrun[0] >= 2 && imax(avefree, avefree30) < desfree &&
e3bf9f41	103	(rate.v_pgin + rate.v_pgout > maxpgio \|\| avefree < minfree))) {
97afa637	104	desperate = 1;
e3bf9f41 BJ	105	goto hardswap;
e3bf9f41 BJ	106	}
97afa637	107	desperate = 0;
e3bf9f41	108	/*
97afa637	109	* Not desperate for core,
e3bf9f41 BJ	110	* look for someone who deserves to be brought in.
	111	*/
	112	outpri = -20000;
1d348849	113	for (rp = allproc; rp != NULL; rp = rp->p_nxt) switch(rp->p_stat) {
e3bf9f41 BJ	114
	115	case SRUN:
	116	if ((rp->p_flag&SLOAD) == 0) {
27b135c8 BJ	117	rppri = rp->p_time -
27b135c8 BJ	118	rp->p_swrss / nz((maxpgio/2) * (klin * CLSIZE)) +
293c7069	119	rp->p_slptime - (rp->p_nice-NZERO)*8;
e3bf9f41 BJ	120	if (rppri > outpri) {
	121	if (rp->p_poip)
	122	continue;
	123	if (rp->p_textp && rp->p_textp->x_poip)
	124	continue;
	125	p = rp;
	126	outpri = rppri;
	127	}
	128	}
	129	continue;
	130
	131	case SSLEEP:
	132	case SSTOP:
	133	if ((freemem < desfree \|\| rp->p_rssize == 0) &&
	134	rp->p_slptime > maxslp &&
	135	(!rp->p_textp \|\| (rp->p_textp->x_flag&XLOCK)==0) &&
	136	swappable(rp)) {
	137	/*
	138	* Kick out deadwood.
e3bf9f41	139	*/
7eb2e67e	140	(void) spl6();
e3bf9f41 BJ	141	rp->p_flag &= ~SLOAD;
	142	if (rp->p_stat == SRUN)
	143	remrq(rp);
7eb2e67e	144	(void) spl0();
e650efcf	145	(void) swapout(rp, rp->p_dsize, rp->p_ssize);
e3bf9f41 BJ	146	goto loop;
	147	}
	148	continue;
	149	}
	150
	151	/*
	152	* No one wants in, so nothing to do.
	153	*/
	154	if (outpri == -20000) {
7eb2e67e BJ	155	(void) spl6();
	156	if (wantin) {
	157	wantin = 0;
	158	sleep((caddr_t)&lbolt, PSWP);
	159	} else {
	160	runout++;
	161	sleep((caddr_t)&runout, PSWP);
	162	}
	163	(void) spl0();
e3bf9f41 BJ	164	goto loop;
e3bf9f41 BJ	165	}
e3bf9f41 BJ	166	/*
	167	* Decide how deserving this guy is. If he is deserving
	168	* we will be willing to work harder to bring him in.
	169	* Needs is an estimate of how much core he will need.
	170	* If he has been out for a while, then we will
	171	* bring him in with 1/2 the core he will need, otherwise
	172	* we are conservative.
	173	*/
	174	deservin = 0;
	175	divisor = 1;
	176	if (outpri > maxslp/2) {
	177	deservin = 1;
	178	divisor = 2;
	179	}
	180	needs = p->p_swrss;
	181	if (p->p_textp && p->p_textp->x_ccount == 0)
	182	needs += p->p_textp->x_swrss;
27b135c8	183	needs = imin(needs, lotsfree);
e3bf9f41 BJ	184	if (freemem - deficit > needs / divisor) {
	185	deficit += needs;
	186	if (swapin(p))
	187	goto loop;
	188	deficit -= imin(needs, deficit);
	189	}
	190
	191	hardswap:
	192	/*
	193	* Need resources (kernel map or memory), swap someone out.
	194	* Select the nbig largest jobs, then the oldest of these
	195	* is ``most likely to get booted.''
	196	*/
e3bf9f41 BJ	197	inp = p;
	198	sleeper = 0;
	199	if (nbig > MAXNBIG)
	200	nbig = MAXNBIG;
	201	if (nbig < 1)
	202	nbig = 1;
	203	biggot = 0;
	204	bplist.bp_link = 0;
1d348849	205	for (rp = allproc; rp != NULL; rp = rp->p_nxt) {
e3bf9f41 BJ	206	if (!swappable(rp))
e3bf9f41 BJ	207	continue;
e3bf9f41 BJ	208	if (rp == inp)
	209	continue;
	210	if (rp->p_textp && rp->p_textp->x_flag&XLOCK)
	211	continue;
	212	if (rp->p_slptime > maxslp &&
89b899a0	213	(rp->p_stat==SSLEEP&&rp->p_pri>PZERO\|\|rp->p_stat==SSTOP)) {
e3bf9f41 BJ	214	if (sleeper < rp->p_slptime) {
	215	p = rp;
	216	sleeper = rp->p_slptime;
	217	}
	218	} else if (!sleeper && (rp->p_stat==SRUN\|\|rp->p_stat==SSLEEP)) {
	219	rppri = rp->p_rssize;
	220	if (rp->p_textp)
293c7069	221	rppri += rp->p_textp->x_rssize/rp->p_textp->x_ccount;
e3bf9f41 BJ	222	if (biggot < nbig)
	223	nbp = &bigp[biggot++];
	224	else {
	225	nbp = bplist.bp_link;
	226	if (nbp->bp_pri > rppri)
	227	continue;
	228	bplist.bp_link = nbp->bp_link;
	229	}
	230	for (bp = &bplist; bp->bp_link; bp = bp->bp_link)
	231	if (rppri < bp->bp_link->bp_pri)
	232	break;
	233	nbp->bp_link = bp->bp_link;
	234	bp->bp_link = nbp;
	235	nbp->bp_pri = rppri;
	236	nbp->bp_proc = rp;
	237	}
	238	}
	239	if (!sleeper) {
	240	p = NULL;
	241	inpri = -1000;
	242	for (bp = bplist.bp_link; bp; bp = bp->bp_link) {
	243	rp = bp->bp_proc;
	244	rppri = rp->p_time+rp->p_nice-NZERO;
	245	if (rppri >= inpri) {
	246	p = rp;
	247	inpri = rppri;
	248	}
	249	}
	250	}
	251	/*
97afa637	252	* If we found a long-time sleeper, or we are desperate and
e3bf9f41 BJ	253	* found anyone to swap out, or if someone deserves to come
	254	* in and we didn't find a sleeper, but found someone who
	255	* has been in core for a reasonable length of time, then
	256	* we kick the poor luser out.
	257	*/
97afa637	258	if (sleeper \|\| desperate && p \|\| deservin && inpri > maxslp) {
7eb2e67e	259	(void) spl6();
e3bf9f41 BJ	260	p->p_flag &= ~SLOAD;
	261	if (p->p_stat == SRUN)
	262	remrq(p);
7eb2e67e	263	(void) spl0();
97afa637	264	if (desperate) {
e3bf9f41 BJ	265	/*
	266	* Want to give this space to the rest of
	267	* the processes in core so give them a chance
	268	* by increasing the deficit.
	269	*/
	270	gives = p->p_rssize;
	271	if (p->p_textp)
	272	gives += p->p_textp->x_rssize / p->p_textp->x_ccount;
9eec1cb0	273	gives = imin(gives, lotsfree);
e3bf9f41 BJ	274	deficit += gives;
	275	} else
	276	gives = 0; /* someone else taketh away */
	277	if (swapout(p, p->p_dsize, p->p_ssize) == 0)
	278	deficit -= imin(gives, deficit);
	279	goto loop;
	280	}
	281	/*
	282	* Want to swap someone in, but can't
	283	* so wait on runin.
	284	*/
e650efcf	285	(void) spl6();
e3bf9f41 BJ	286	runin++;
e3bf9f41 BJ	287	sleep((caddr_t)&runin, PSWP);
7eb2e67e	288	(void) spl0();
e3bf9f41 BJ	289	goto loop;
	290	}
	291
	292	vmmeter()
	293	{
	294	register unsigned cp, rp, *sp;
	295
27b135c8 BJ	296	deficit -= imin(deficit,
27b135c8 BJ	297	imax(deficit / 10, ((klin * CLSIZE) / 2) * maxpgio / 2));
e3bf9f41	298	ave(avefree, freemem, 5);
27b135c8	299	ave(avefree30, freemem, 30);
e3bf9f41 BJ	300	/* v_pgin is maintained by clock.c */
	301	cp = &cnt.v_first; rp = &rate.v_first; sp = &sum.v_first;
	302	while (cp <= &cnt.v_last) {
	303	ave(rp, cp, 5);
	304	sp += cp;
	305	*cp = 0;
	306	rp++, cp++, sp++;
	307	}
c4206698	308	if (time.tv_sec % 5 == 0) {
e3bf9f41 BJ	309	vmtotal();
	310	rate.v_swpin = cnt.v_swpin;
	311	sum.v_swpin += cnt.v_swpin;
	312	cnt.v_swpin = 0;
	313	rate.v_swpout = cnt.v_swpout;
	314	sum.v_swpout += cnt.v_swpout;
	315	cnt.v_swpout = 0;
	316	}
	317	if (avefree < minfree && runout \|\| proc[0].p_slptime > maxslp/2) {
	318	runout = 0;
	319	runin = 0;
	320	wakeup((caddr_t)&runin);
	321	wakeup((caddr_t)&runout);
	322	}
	323	}
	324
c4206698 BJ	325	/*
	326	* Schedule rate for paging.
	327	* Rate is linear interpolation between
	328	* slowscan with lotsfree and fastscan when out of memory.
	329	*/
	330	schedpaging()
e3bf9f41	331	{
a2faae5d	332	register int vavail;
e3bf9f41	333
e3bf9f41 BJ	334	nscan = desscan = 0;
	335	vavail = freemem - deficit;
	336	if (vavail < 0)
	337	vavail = 0;
e4d539fa	338	if (freemem < lotsfree) {
a2faae5d KM	339	desscan = (slowscan * vavail + fastscan * (lotsfree - vavail)) /
a2faae5d KM	340	nz(lotsfree) / RATETOSCHEDPAGING;
e4d539fa SL	341	wakeup((caddr_t)&proc[2]);
e4d539fa SL	342	}
b32450f4	343	timeout(schedpaging, (caddr_t)0, hz / RATETOSCHEDPAGING);
e3bf9f41 BJ	344	}
	345
	346	vmtotal()
	347	{
	348	register struct proc *p;
	349	register struct text *xp;
	350	int nrun = 0;
	351
	352	total.t_vmtxt = 0;
	353	total.t_avmtxt = 0;
	354	total.t_rmtxt = 0;
	355	total.t_armtxt = 0;
fcb2d36b	356	for (xp = text; xp < textNTEXT; xp++)
e3bf9f41 BJ	357	if (xp->x_iptr) {
	358	total.t_vmtxt += xp->x_size;
	359	total.t_rmtxt += xp->x_rssize;
	360	for (p = xp->x_caddr; p; p = p->p_xlink)
	361	switch (p->p_stat) {
	362
	363	case SSTOP:
	364	case SSLEEP:
	365	if (p->p_slptime >= maxslp)
	366	continue;
	367	/* fall into... */
	368
	369	case SRUN:
	370	case SIDL:
	371	total.t_avmtxt += xp->x_size;
	372	total.t_armtxt += xp->x_rssize;
	373	goto next;
	374	}
	375	next:
	376	;
	377	}
	378	total.t_vm = 0;
	379	total.t_avm = 0;
	380	total.t_rm = 0;
	381	total.t_arm = 0;
	382	total.t_rq = 0;
	383	total.t_dw = 0;
	384	total.t_pw = 0;
	385	total.t_sl = 0;
	386	total.t_sw = 0;
1d348849	387	for (p = allproc; p != NULL; p = p->p_nxt) {
e3bf9f41 BJ	388	if (p->p_flag & SSYS)
	389	continue;
	390	if (p->p_stat) {
	391	total.t_vm += p->p_dsize + p->p_ssize;
	392	total.t_rm += p->p_rssize;
	393	switch (p->p_stat) {
	394
	395	case SSLEEP:
	396	case SSTOP:
89b899a0	397	if (p->p_pri <= PZERO)
e3bf9f41 BJ	398	nrun++;
	399	if (p->p_flag & SPAGE)
	400	total.t_pw++;
	401	else if (p->p_flag & SLOAD) {
89b899a0	402	if (p->p_pri <= PZERO)
e3bf9f41 BJ	403	total.t_dw++;
	404	else if (p->p_slptime < maxslp)
	405	total.t_sl++;
	406	} else if (p->p_slptime < maxslp)
	407	total.t_sw++;
	408	if (p->p_slptime < maxslp)
	409	goto active;
	410	break;
	411
	412	case SRUN:
	413	case SIDL:
	414	nrun++;
	415	if (p->p_flag & SLOAD)
	416	total.t_rq++;
	417	else
	418	total.t_sw++;
	419	active:
	420	total.t_avm += p->p_dsize + p->p_ssize;
	421	total.t_arm += p->p_rssize;
	422	break;
	423	}
	424	}
	425	}
	426	total.t_vm += total.t_vmtxt;
	427	total.t_avm += total.t_avmtxt;
	428	total.t_rm += total.t_rmtxt;
	429	total.t_arm += total.t_armtxt;
	430	total.t_free = avefree;
	431	loadav(avenrun, nrun);
	432	}
	433
	434	/*
	435	* Constants for averages over 1, 5, and 15 minutes
	436	* when sampling at 5 second intervals.
	437	*/
	438	double cexp[3] = {
	439	0.9200444146293232, /* exp(-1/12) */
	440	0.9834714538216174, /* exp(-1/60) */
	441	0.9944598480048967, /* exp(-1/180) */
	442	};
	443
	444	/*
	445	* Compute a tenex style load average of a quantity on
	446	* 1, 5 and 15 minute intervals.
	447	*/
	448	loadav(avg, n)
	449	register double *avg;
	450	int n;
	451	{
	452	register int i;
	453
	454	for (i = 0; i < 3; i++)
	455	avg[i] = cexp[i] * avg[i] + n * (1.0 - cexp[i]);
	456	}