On the use of ‘top stack sets’ for the storage management of a paged stack machine

45 ON THE U~E~ OF "TOP STACK SETS' FOR THE STORAGE MANAGEMENT OF A PAGED STACK MACHINE

bw P.

M o c r e s and G . F .

Coulou~is

M£MBERS P r o J e c t D~ortment

of" C o ~ u ~ e r S c i e n c e and S t a t i s t i c s

Qu~n Mo~ Collese,

IJniv~sltw

of" London

Abstract The d e v e l o D ~ n t of" o s t o r a m e ~ n o m e s ~ t scheme f`or MEMBERS, on e m u l a t e d s t o c k machine i n c o r ~ o r o t l n m a v i r t u a l s t o r e and moainm, i s d e s c r i b e d . The a p p r o a c h used e ~ l o ~ s on o n o l o ~ u ~ o f~ t h e ' w o r k i n s s e t ' c o n c ~ t of" D e n n i n g . I n f o r m a t i o n c o n t a i n e d in t h e a c t i v a t i o n s t o c k £ o r each = r o c e s s i s used t o i d e n t i + ' ~ o ' T o o S t o c k S e t , ~'op t h e p r o c e s s . The s e t of" a l l t h e t o ~ s t o c k s e t s d e f ` i n e s t h e moses t h a t o r e h e l d in Main s t o p o m e . T h e a r c h i t e c t u r e of" t h e MEHBERS machine i n c o r m o r a t e s on o c t a v o t i o n s t o c k in w h i c h a o i n t e r s can b e d i s t i n m u i s h e d ~'roM other data. The basic Drosrammins lonsuome ~'or the ~chine i s d e s i s n e d t o e n c o u r o s e o m o d u l a r s t r u c t u r e .fop , r o m r e m s , s o t h e a c t i v a t i o n r e c o r d s in t h e s t o c k ~ o r t h e r e c e n t l w e n t e r e d a r o c e d u P e s c o n t a i n p o i n t e r s t o on o = , m r o x i n t o . t i o n 04~ t h e w o r k i n s set. The u s e o4" m i c r o ~ r o m r o m m i n s f"or t h e i ~ l ~ n t a t i o n o~ " t h e s t o r o s e manosen~-~nt s ~ s t ~ i s a l s o d i s c u s s e d and some arelimlnor~ estimates o~ its pQt'f"orw~unce ore siren.

1.

The MEMBERS M a c h i n e

MEMBER¢3 i s an e x p e r i m e n t a l e m u l a t e d machine [ 8 ] d e s i s n e d and b e i n g d e v e l o p e d a t QMC , w h i c h i s i n t e n d e d f o P s m a l l and a~dium s c a l e r e o l - t i ~ amDlications. This is currentlw beinn emulated using Micrc~rosro~MJinm o n a n I n t e r d c t t a Model 4 micro~rogroJnmOble c o m ~ u t e r , w i t h 4K 1 6 - b i t 0 . 4 M i c r o s e c o n d W P i t e o b l e C o n t r o l S t o r e (WCS), 3.2K x 16 b i t (64K b w t e s ) c o r e s t o r e ( 2 . 4 u s e c ) , 512 K b~t, e s of" drum s t o r e and a number alp aer i ~her ol s.

46

The machine was d ~ - s i ~ e d wit,h t h e v i e w t,hat t h e ~ i n emphasis~ would be not, on t h e n u m b ~ o~" o p e r a t , i o n s a v a i l a b l e r but on v e r s a t i l i t ~ a~ _ +'or a s d a t a s t r u c t u r e s a r e c o n c e r n e d . So t h e ~ c h m n e o ~ ? e r s a w h o l e r a n s e o+" ? a c i l i t , i e s ? o r r e p r e s e n t i n s and ~ a n i ~ u l a t , i n g d a t a s t r u c t , u r e s o÷" v a r i o u s d e s r e ~ s o¢ c o m D l e x i t w , chc~ckin~ t h e v a l i d i t ~ o~ o o e r o n d s and a d d r e s s e s s o a s t o s i r e e÷'÷'ect ive run-t, i ~ d i o g n o s t its, m a n it,or ing, chcuns ~ns p r o g r a m s at run-time b~ reco~pilins individual £unct,ions, etc. The above objectives are achieved b~ the architectural characteristics of the machine:

£ollowinm

main

(i) S t a c k - o r i e n t e d Instructions, m o ~ . l ~ o n e bwC.e I o n s . T h i s results in c o m p a c t code seg~nts, which is o f a r e o t i~ortonce ~or pagins. (ii) A Codeword T a b l e w h i c h i s a s o r t o£ a s o p h i s t i c a t e d ma~ins device, with structural in?oration on t h e l i n e s of" I I i ÷ ' ? e ' s B a s i c M a c h i n e c o d e w o r d s and B u r r o u g h s D~rscri=t,or Table [ 1 ] . (iii) A stac~( ~'or each ~ r o c e s s . S t o c k e l e ~ n t s are the r e s u l t s of" e v a l u ~ t i n ~ e ~ p r e s s i o n s and a r e 3 2 - b i t s l o n ~ .

MEMBER,~ b a s i c l = n ~ u a ~ e i s c a l l e d FLUII~. T h i s i s e q u i p p e d w i t h o ~ e r o ~ o r ~ and f ' u n c t , i o n s which w e r e c o n s i d e r e d a~rc~riate in ~ r e a l - t . i ~ a ~ l icat, ion e n v i r o n m e n t . The Ioneua~e can be ~t.ended b~ oddin~ n e w +'unct,ions a n d £ a c i l i t i e s t o c a t e r £or s~ecial real-t,i~e o~plicat,ions like ti~--sharins £or co~uter-ed~ca~ional purposes, o n l i n e i n t e r p r e t iv e s c i e n t , i £ i c com~utation, vrocess and ~lant control, etc. FLUID con serve bo~h a s a command l a n s u a ~ e and a s o n o r ~ o l p r o ~ r a m m i n s l a n s u o ~ e . From a st,erase manasement =oint, o~" v i e w t h e M E M B E R S hard.are h a s ~ 4 K b,~te~ o £ c o r e s t o r e a n d 1 9 2 K b~Jtes of" d r u m s t o r e i n t e s r a t e d b~ t h e s t o r a g e m~na~ement s ~ s t ~ in a t o ~ o l o£ ~K b ~ t e s o~ v i r t u a l s t o r e o r ~ a n i s e d in 4 v o l u ~ e s o~ 64K b ~ e s eocho Each v o l u ~ e c o n s i s t s o+" 256 ~ a s e £ r a ~ s o~ 256 b ~ e s e a c h .

~ i n c e ~ r o ~ r a m ~ , r e f ' e r e n c e s t o s t o r a s e in t h e MEMBERS m a c h i n e a r e d i r e c t e d t h r o u g h t h e codeword t a b l e , a v i r t , u a l a d d r e s s i s ~ a r t , l g s ~ b o l i c ( i . e . s e ~ e n t , names t r a n s l a t e i n t o codeword t a b l e r e ~ e r e n c e s ) and need no~ h a v e an~ n u ~ r i c representation that i s a c c e s s i b l e ? o r m a n i p u l a t i o n b~ p r o s r a ~ s . I n such s ~ s t e ~ s , t h e a d d r e s s a b l e ~ t , o r e i s s a i d t o be s ~ b o l i c c t l l w sesment,ed. S i n c e s e s m e n t s ma~ be o~" a r b i t r o r ~ l e n s t h , t h e = a e i n s s ~ s t e ~ i s r e q u i r e d = u r e l ~ a s a means o¢ i n t e e r a t i n s t h e t w o s t o r a m e l e v e l s ( i . e . c o r e and drum) and n o t t o p r o v i d e on e~tended v irt,uol address s~oce.

2.

A Sl~orase Monasement s c h e ~ The s ~ o r a s e ~ n a s e ~ n t

~ o r t h e MEMBERS ~ c h i n e

o~ MEMBERS i s b a s ~

on t h e

'workins

47 ~d~'

principle

E4].

The ~in reasons tF'or t h e c h o i c e o~" t h e w o r k i n s set. appro~ch derive from the definition of the workins set. Efficienc~ o~" t h e ~ k i n e set approach in weneral is a function o~ the desree o~" I O ¢ : C L l i L ~ [ 4 p 7 3 on aPPlication protrom exhibits a n d o f t h e econom,..J o'f" i ~ l e m e n t a t i o n on a sive~n machine. In MEH]EeER~ , be/oh o~" t h e s e require~ent.s can be ~t. First, FLUID, the promro~inm lonmuome for ~ , has o structure that enhances locol itw b~ encour-asins the mromroJmN~r to br~o~ do~n the coMputinm ~unction into relativelw small procedures. Each procedure constitutes a ma~ent, and ~ of t h e semments a r e l e s s t h a n a p o s e in l e n g t h . (Monw MEMBERS i n s t r u c t ions a r e onl~ one b ~ . e l e n t o , so a p o s e can occomodate u~ t o 256 i n s t r u c t i o n s . ) As f o r a s i m p l e m e n t a t i o n i s c o n c e r n e d , t h e p r i n c i p a l p r o b l e m i s t o d e f i n e a r e e s o n a b l ~ economic a l l o r i t h M t h a t can ident if~ the current workins s~ of each mrocess. Earlier i~lementat ions h a v e r a n g e d f r ~ ctll-hardwore s~ste~ (as in MANIAC II [ 1 2 3 ) , w h i c h w e r e prc~t~,~ e f £ i c i e n t , b~ costl~ and inconvenient to implement, es~eciall~ for e~istin~ machines, to oll-scyFtware s~stems, im~osin~ ver~ larse overheads on s~ste~ ~er for monc~. in o u r c a s e , s i n c e t h e M E M B E R S m a c h i n e includes a run-4~i~ s t a c k w i t h t~pe t o e s , t h e workins variables (paramef.ers, locals, e ~ t e r n a l s ) cyF t h e ~ o s t r e c e n t l ~ e n t e r e d p r o c e d u r e s can be e a s i l ~ f o u n d amon~ t h e t o ~ - m o s t sl~ach e l ~ m e n t s in t h e s t a c k s p a c e of" each ~ r o c e s s . W~ . ~ . a t e in fact, that a portion (~o~ extent will be defined) of each process' stack const ituLes t h e b a s e ~PoP ~.he w o r k i n s set o f t h a t p r o c e s s . Since s t a c k e n t r i e s a r e e i t h e r t o s ~ e d d a t a v a l u e s o r t o s s e d p o i n t e r s t o o + ' ? - s t a c k d a t a , an o p p r o ~ i m o t ion t o t h e f u l l w o r k i n ~ s e t can be e v a l u a t e d f r o m t h e b a s e b~ ? o l l o w i n a a l l o f t h e p o i n t e r c h a i n s t h a t a r e based in it. T h i s s e t , h o w e v e r , d o e s n o t i n c l u d e o11 o~ t h e most r e c e n t l ~ a c c e s s e d p o s e s , b e c a u s e due t o o c c a s i o n a l s t a c k c o l l a p s e s , some o f t h e p o s e s a l t h o u e h r e c e n t l ~ r e f e r e n c e d a r e , in f a c t , invisible from the to~ of the stock. We h a v e t h e r c ~ f ' o r e c o i l e d t h e s e t o~ p o s e s i d e n t i f l e d bw t h e a b o v e method t h e T o ~ - s t a c k S e t , o r s i l l s To~ Set i n s t e a d o~ workinm s e t s i n c e t h i s would i ~ l ~ t h e c o ~ o i e t e s e t o~ t h e ~ o s t r e c e n t l w re~eerencc-~d p o s e s . The a b o v e d i s c u s s i o n i n d i c a t e s t h a t a t a r e a s o n a b l e c o s t , we can d e v i s e a sound s t o r a s e n~uno~ement s~stem b~ e x ~ I o i t i n s t h e s t r u c t u r e o~" t h e MEMBERS ~ o c h i n e . T h i s i s in l i n e w i t h

48 B e l o d ~ ' s c o n c l u s i o n in [ 5 ] t h o r o ~o~d r e p l o c e m e n t c t l s o r i t h m s h o u l d be ? o i r l ~ s i m ~ l m , ~ e t on t h e o t h e r hond s h o u l d p o s s e s s some p r e d i c t i v e power bosed on s t o r e d i n ? o r m o t i o n t h o r i s eos~ t o m o i n t o i n ond u ~ e .

2.1

To= Set

sizes

A ?ew w o r d s now o b o u t t h e c h o i c e o~ t h e s i z e o£ t h e Top S e t ° S i n c e b~ d e ? i n i t i o n t h e s i z e s h o u l d be such a s t o s e c u r e r e o s o n o b l e c ~ f ' ~ i c i e n c ~ in r u n n i n s t h e ~ r o c _ e s s , one h o s t o t o k e i n t o o c c o u n t t h e demonds ? o r c o r e o~ eoch = r o c e s s . T h i s demond i s o ? u n c t i o n o? t h e k i n d o? o ~ l i c o t i o n this process represents ond i t s c u r r e n t s t o ~ e o~ e x e c u t i o n . To r e ? l e c t t h i s we i n t r o d u c e :

li?e,

oscillotion

in demond, d u r i n s

o process's

~ . The B o s i c Top S e t , o D o r o m e t e r c h o r o c t e r i s t i c o? t h e opplic~tions. W i t h s i z e d e n o t e d b~ SBi ~ o r p r o c e s s number i . b . The C u r r e n t Top S e t , o s s o c i o t e d w i t h t h e s t o s e o? e ~ e c u t ion t h e p r o c e s s i~o c u r r e n t l _ ~ i n . W i t h s i z e d ~ n o t e d b~ SCi ?or p r o c e s s i . A b o s i c Top Set s i z e w i l l be o l l o t t e d b~ t h e o ~ r o t i n s s~stem ~o ~ o c h . p r o c e s s e n t e r : n s t h e s ~ s t e m , t h e n t h e p r o c e s s will be i ~ ? t t o o d J u s t i t s t o p s e t d ~ n c u ~ i c o l l ~ , i n c r e o s i n 5 o r d e c r e o s i n s i t s s i z e o c c o r d i n ~ t o t h e pose ? o u l t r o t e a~ eoch s ~ o s e o? e x e c u t i o n . The r e s u l t i s t h e c u r r ~ n t Top Set s i z e , ond i s i n t e n d e d t o r e p r e s e n t o more ~ r e c i s e i n d i c o t i o n o? t h e s t o r o g e r e q u i r e m e n t s oF o = r o c ~ s s o t on~ i n s t o n t , t o k i n ~ c u r r ~ n t t o t o l demond ? o r s t o r a s e i n t o o c c o u n t .

~.2

The R e p l o c e m e n t A l s o r i t h m

The r o l e oF t h e R e p l a c e m e n t A i s o r i t h m i s t o kee~ in c o r e oll o? t h e p o s e s t h o r must be r e s i d e n t ( l o c k e d ) in c o r e ond t h e p o s ~ s b e l o n s i n g t o t h e Top S e t s o~ t h e c u r r e n t l ~ o c t i r e p r o c e s s e s . A l l o ~ h e r p o s e s o r e ? r e e d b~ t r o n s ? e r r i n s their c o n t e n t s o n t o t h e drum. So when t h e (o) re?lectins sets).

allow

(b) the

All of their

ReDlocement R o u t i n e

is

?inished:

the octive processes hove o shore in c o r e present demond on t h e s w s t e m (i.e. their tom

There is o n u m b e r o? ?rme mo~es processes to expond ot r u n t i m e

ovoiloble so (the pdol).

as

to

49 S t e p 2 i d e n t i ~ i e s t h e C u r r e n t ToP S e t f o r t h o s e a r o c e s s ~ s £ o r w h i c h S C i > S M i , i . e . t h e C u r r e n t To~ S e t i s l a r g e r t h e n t h a t resulting £rom s t e a I . On c o ~ l e t i o n o f s t e p s 1 end 2 , e l l o~ t h e c o r e p o ~ e s n o t i n c l u d e d in on~ Tea Set o r e e n t e r e d in t h e Drum Pose k ~ , £or t r o n s ~ e r t o t h e d r u ~ , l e o v i n ~ f r e e po~e £rctmes in c o r e .

2.3

Some

(o)

Saocm

Initiol

F'er~ormonce M ~ s u r e m e n t s

The st o r ~ e m o n o g e ~ n t s~stem o c c u p i e s J u s t o v e r t w o poges o~" t h e WCS (one p e r p h a s e ) end u s e s t w o pos~s o£ c o r e s t o r e t o mo i n t o i n ~ ~ p o f ~a~e s t o t u s . So, in p r o c t i c e , t h e c o s t of" o u r s t o r o s e mano~ement s~stem in t e r n s o~" s a o c e in WCS i s J u s t o v e r one a a ~ e , most l ~ o c c u o i e d b~ t h e F'hose A ( P o s e f a u l t ) routines, and o u e r l o ~ d b~ F'hase B ( r e p o c e m e n t r o u t i n e ) o t P e r i o d i c in~ervols. (b)

Timing

~ o s u r e m e n t s t a k e n on t h e o c t u o l s t o r o g e ~ n a g e m e n t swstetn c o d e in a s i m u l a t e d P r o c e s s e n v i r o n m e n t a r e v e r ~ e n c o u r o e i n g £ o r t h e P e r ~ o r m o n c ~ o f t h e s t or o s e ~ n a m e m e n t s ~ e m in o r e a l e n v i r o n m e n t . We h o v e o b t o i n e d t h e . £ o l l o w i n s results:

(i)

~or

F1

(Pose ~ a u l t

s~rvicins)

on o v e r a g e o £ :

0.335 milliseconds/Dome ~oult

(ii)

~ o r F2

(rePloc~nt

olgorithm)

F o r lO--poge ToP S e t s t h e t i m e i s s i r e n bw t h e f ' o r m u l a C9]) : 7 + (p x 0 . 6 5 ) m i l l i s e c o n d s

(see

w h e r e a i s t h e number o~" p r o c e s s e s c o n s t i t u t ing t h e current multiprogrommin9 level. ( e . g . 10 p r o c e s s e s w o u l d r e q u i r e on o v e r a s ~ o+" 1 3 . 5 m i l l i s e c o n d s ) .

3.

Conclusions

50 The c h o i c e o~ t h e s i z e o~" t h e p o o l i s c r i t i c a l +'or t h e p e r + ' o r m ~ n c e o+" t h e s ~ s t e m b e c a u s e i t d i c t a t e s how o ~ t e n t h e r e p l a c e l a e n t r o u t i n e has t o be c a l l e d i n . I t must b e l a r s e e n o u s h t o r e d u c e t h e t i m e s p ~ n t i n t.he r e D l a c e a ~ m t r o u t i n e t o a reasonable l~vel, and ! ~ e t s m a l l e n o u s h t o a l l o w a s much s ~ a c e a s p o s s i b l e +'or t h e a c t i v e p r o c e s s e s ° !

The o ~ t i m u m s i z e ~ o r t h e p o o l w i l l b e t h e s u b j e c t a~ simulation studies, but as a startins p o i n t 20% o+" t h e ~ o t a l core store is considered a reasonable choice. This choice, in our particular c a s e makes a p o o l o~ 50 p o s e s . I n a d d i t i o n to this p o o l , : w e hod t o i n t r o d u c e a n o t h e r s ~ s t e m p a r a m e t e r w h i c h r e ~ r e s e n t s t h e m i n i m u m number o~ a a ~ e s t h a t must r e m a i n +'ree in t h e swstem o t an~ t i m e . T h i s a c t s as t h e c o n d i t i o n +'or t h e R e p l o c e m e n t R o u t i n e t o s t e p i n ° The s i z e o ? t h i s t h r e s h o l d whose usefulness will be a p p a r e n t l a t e r in t h i s s e c t i o n h a s been c h o s e n e q u a l t o a r o u n d 2% o~ t h e t o t a l core store ( 4 - 5 p o s e s in OU~

CaSe)=

So when t h e s ~ s t e m r e s u m e s . r u n n i n s a + ' t e r t h e e x e c u t i o n o+' the replacement routine a p o s e demand c a n be s r a n t e d i m m e d i a t e l ~ b~ a s s i s n i n s an~ o ¢ - t h e + ' t e e p o s e s a~ t h e p o o l t o t h e d e m a n d i n g p r o c e s s . T h i s c a n s o on ~ o r a number o~ p o s e + ' a u l t s N = p o o l s i z e - t h r e s h o l d s i z e . When a number o~ +'tee p o s e s e q u a l t o t h e threshold is reached, the replacement routine takes overasain. Now'we o r e in o p o s i t i o n t o o b t a i n on i n s i s h t into the o p e r a t i o n of" t h e r e p l a c e m e n t r o u t i n e . The +'act t h a t i t must e n s u r e t h l e r e l e a s e o+" a number at" p o s e s t o t h e p o o l i m p o s e s a limit on '0he number o~" p r o c e s s e s w h : c h a r e a l l o w e d t o h a v e t h e i r t o p s e t s i n c o r e . T h i s c o n be s e e n a s a c o n t r i b u t i o n to process schedulins, s i n c e o n l ~ t h e p r o c e s s e s t h a t t h e s ~ s t ~ m can a+'+'ord .-t o n ~ t i m e o r e a l l o ~ e d t o r u n . I t a l s o p r o v i d e s an e+~+'ectiue s£1f'e~uard a s o i n s t t h r a s h i n s s i n c e t h e s c h e d u l e r d ~ n a m i c a l l ~ re-adjusts t h e m u I L i p r o s r o n w a i n e l e v e l o+" t h e s ~ s t e m w h e n e v e r t h e repacement routine is ~×ecuted. The r e p l a c e m e n t r o u t i n e i d e n t ; i + ' i e s t h e Top S e t ? o r e a c h a c t i v e p r o c e s s . T h i s p r o c e e d s i n t w o s t e p s ; s t e p 1 u s e s a Top S e t sizo~ SNi f o r e a c h p r o c e s s . SMi = m i n ( S B i , S C i ) i s t h e minimum number at" p a s t s r e q u i r e d ~ o r p r o c e s s i t o r u n . I t s v a l u e r e p r e s e n t s .o c o m p r o m i s e b e t w e e n a memor~ l o a d r e + ' l e c t i n s t h e c u r r e n t demand ~'or memor~ b~ e a c h p r o c e s s ( S C i ) and t h e n e e d a t t imes t o r u n m o r e p r o c e s s e s t h a n c o u l d be a c c o m o d a t e d in t h e strict workids set model.

step Joe.

S t e p 2 i s e × e c u t e d o n l ~ i+" t h e Top S e t s r e s u l t i n s +'ram 1 c a n be a c c c ~ , o d a t e d and t h e r e i s s t i l l some ~ o a r e memorw. s t e p 2 i s u s e d when

Y--SMi t

<

number o+" c o r e a p s e s -

pool

size

51

The s e n e r a l o i m s o f

t h e ~ r o J e c t d e s c r i b e d were as ~ o l l o ~ s :

Firstl~, to investisote the senerol relationship bet w ~ n s t o r ~ s e m o n a s e ~ n t s t r o t e s , a s and t h e ~ o c h i n e d e s i g n s ? o r w h c i h t h e ~ o r e i n t e n d e d . A c a r e f u l c o n s i d e r a t i o n o? a l l t h e ? a c t o r s i n v o l v e d s h o u l d d i c t a t e t h e a p p r o p r i a t e s t o r o ~ e mona~ement schame F o r a s i r e n ~ c h i n e . As an i l l u s t r a t i o n of" t h i s a = m r o o c h , we hav~ d e s c r i b e d t h e s~stem d e v e l o p e d £ r o ~ t h e MEMBERS m a c h i n e =roJect [83. S e c o n d l ~ , ~s ? o r a s t h e d e s i g n o f t h e ~-~,orose ~ o n o s e ~ e n t scheme i t ~ e l ? i s c o n c e r n e d , an o t t ~ t has been made t o s t r e s s t h e c o n s u l t a t i v e r o l e o f t h e s ~ s t e m . T h i s can be seen a s a f u r t h e r a t t e m p t t o l i b e r a t e t h e c o m ~ u t e r u s e r ?ram t h e authoritative power ~ " t h e ~,...~---~,em. Our main c o n c e r n i s t o t r e a t t h e w h o l e p r o b l ~ o f s~oro~e management in a n a t u r a l and c o n u e n i e n ~ wa~= The s~stem o ~ e r o t e s in t e r m s o¢ p r o c e s s e s r a t h e r t h a n i n d i v i d u a l p a g e s . The p r o c e s s e s , a s t h e ~ m b e r s o¢ ~ communit~ s h o r i n g a number o¢ r e s o u r c e s , p o s s e s s much u s e f u l d a t a on t h e i r own n e e d s . Th~ r o l e o# t h e s~stem i s J u s t t o i d e n t i ? ~ t h e i r needs and m a i n t a i n balance (occordin~ to prede~ined ~riorities), b e t wwen t h e s e demands and what t h e s~stem a s a w h o l e can aCCord.

4.

Acknowledgments

The worl~ d e s c r i b e d has been c a r r i e d o u t o f t h e MEMBEE~ research project, s p o n s o r e d b~ t h e S c i e n c e R e s e a r c h C o u n c i l (Re#. B / R G / 5 0 0 ) . W~ s h o u l d l i k e t o t h a n k t h o s e c o l l e Q s u ~ s and £ e l l o w - ~ t c ~ e n t s who h o v e p a r t i c i p a t e d in t h e p r o 3 ~ c t and h ~ v e ~ode v a i u ~ b l e c o n t r i b u t i o n s t h r o u g h d i s c u s s i o n s t o t h e w o r k d e s c r i b e d ha~e. In p a r t i c u l a r we s h o u l d l i k e t o t h a n k J . K . B r o o d b e n t Car n~uch h e l p # u l a s s i s t a n c e .

5.

Re?c-fences and B i b l i o s r o ~ h w

1.

J.K. lli?#e 'Basic ~ochine PriniDles' M c D o n Q l d / E 1 s e v i e r Coa,~. MonosrQphs, 1 9 6 9

2.

J.K. Ili?£e, KJ.L. gilliss ' A s t o r e Mo~nase~nt s c h e ~ u s i n s BL~' 29, ICL, SteuenQse, H e f t s .

a single

seln~nt table'

52 F'. Dennin~ " V i r t u ~ 1 memory' Co~utins surveys Uol.

2,

NO.3

4.

P. Dennin5 ' T h e Workins Set Model ~or Prosram B e h a v i o u r , CACM Vol 11, NO. 5

5.

L . A . Beladw ' A s t u d ~ o~" r e p l a c e t ~ e n t IBM Swstems J o u r n a l V o l .

c t l s o r i t h M s ~or a v l r t u a l 5 No. 2

6.

B . S . Brawn, F.G. Gustavson P r o s r ~ B e h a v i o u r in a P Q I i n g E n v i r o n m e n t ' Fall Joint ~uter C o n f e r e n c e 1967

7.

L . A . B e l a d ~ , G . J . Kuehner 'D~naMic S ~ a c e - S h a r i n s in Conmuter ShJstems, CACM V o i . 1 2 , No. 5

8.

J . K . B r o o d b e n t , G.F. C o u l o u r i s 'HEMBERS-A Mi croprosram~--~l E>a~er i ~ent a l Machine w i t h a B a s i c E x e c u t i v e ~'or R~oI C o ~ u t e r J o u r n a l , Ausust 1 9 7 3 .

stor, ase com=uter'

TiMe S~stc~ts'

9.

F'. M a t t e s 'To=) S t a c k S e t s For t h e S t o r o s e ManameMent of" t h e NEMBE~"3 Machine' HEMBEE~3 Report. N o . 1 2 , A ~ r i l 197:3

10.

P. M a t t e s A Sf.at i s t icaLl S i M u l a t ion Model o¢ t h e S t o r a s e Management, o~" t h e PtEMBERS roach i n e ' Iv~EMBE~ Spec. F~I/2, J u l ~ 1973

11

P. ~r'res 'St, o r e Hctnosem~nt S~R'ue~ and P r o P o s a l s For t h e ~ R S ~ c h i ne j' MEMBEK~3 S~e¢ PM/Z

12

J.B. Morris • Detn~nd F'agins Throush U t i l i z a t i o n on t h e i ~ l ~ E II'

CA~,~I U o l .

15 No. 10

o+" Working S e t s