e reditive ystem hutdown wetho d for inergy ving of iventEhriven gomputtion ghiErong rwng nd ellen gFErF u heprtment of gomputer ieneD sing ru niversity rsinhuD iwnD QHHD epuli of ghin fhunghwdsFnthuFeduFtwg estrt sn reent studyD rivstv et lF U onduted n extensive nlysis on dierent systemEshutdown pE his pper presents systemElevel power mngement prohesF heir smple tres on n EserverD n eventE tehnique for power sving of eventEdriven pplitionsF driven pplitionD showed tht it sp ends over WH7 of its e present new preditive systemEshutdown methodto time in the lo ked stte nd the verge time visiting exploit sleep mode opertions for power svingF e use the lo ked stte is less thn one seondF es resultD n exponentilEverge pproh to predit the upoming the onventionl pproh will fil to eetively hieve id le periodF e introdue two mehnismsD preditionE power redution on this typ e of pplitionF hey hve miss orretion nd preEwkeupD to improve the hit rtio prop osed preditive systemEshutdown tehnique for enE nd to redue the dely overhedF ixperiments on four ergy sving of eventEdriven pplitionsF hey rst olE dierent eventEdriven pplitions show tht our proE leted smple tres of onEo tivity on n EserverF posed method hieves high hit rtios in wide rnge of henD they prop osed two preditive formuls sed on dely overhedsD whih results in high degreeofpower the nlysis of the smple tresF he rst formul ws sving with low dely penltiesF otined y using generl regressionEnlysis tehnique I sntro dution to orrelte the length of the up oming o p erio d to the ith the dvent of p ortle omputing nd high denE lengths of the previous on nd o p erio dsF he seond sity vs iruitsD p ower dissiption hs emerged s formul ws otined y the oservtion of the onEo E priniple design onsidertion in vs designsF sn the tivity ehviorF hey oserved tht the idle p erio d folE pst few yersD hndful of p ower estimtion nd miniE lowing long running p erio d tends to e short4F fsed miztion metho ds hve een rep orted for hieving low on this oservtionD they derived formul whih lters power designs t iruitD lyoutD logiD ehviorlD nd out the idle p erio d fullling the ove ondition nd the rhiteturl levelsF everl exellent reviews of p ower system enters the sleep stte otherwiseF fsed on the estimtion nd minimiztion tehniques re given yeE two formulsD they onduted series of exp eriments on drm ID hevds nd wlik PD nd x jm QD RF n lient pplitionF he results demonstrted tht vowpower vs designs n e hieved t vriE preditiveshutdown tehniques n redue the p ower ous design levelsF sn this studyDwe fo us on utilizing onsumption y lrge ftor ompred to the onvenE preditive systemEshutdown tehnique for p ower svE tionl metho dF roweverD one drwk of this pproh ing of eventEdriven pplitionsF ower mngement is tht the preditive formul is diretly derived from tehniques hve een extensively pplied to g systemsF the smple tres of sp ei pplitionF por dierent por instneD the design of the owergTHQ S pplied pplitionsD dierent preditive formuls re needed in twotyp es of p ower mngementshemesX stti nd dyE order to mke urte preditionsF nmiF sn stti p ower mngementD the system denes sn this pp erD we present new preditive systemE severl sleep mo des with vrious levels of p ower sving shutdown metho d for eventEdriven pplitionsF e use nd delyoverhed whih n e ontrolled externlly wellEknown exp onentilEverge pproh to predit y softwreF sn dynmi p ower mngementD the system the up oming idle p erio dF eintro due two mehE will utomtilly detet the idle p erio ds nd disle the nismsD preditionEmiss orretion nd preEwkeupD to imE lo ks on p ortions of the g F epple9s w owerfo oks prove the hit rtio nd to redue the delyoverhedF T use dierent pproh whihenters rest mo de fter ixp eriments on four dierenteventEdriven pplitions P seonds of idle timeF huring rest mo deD the pro essor re rep orted to demonstrte the eetiveness of our proE is p owered down ut the sGy devies remin onF ypiE p osed metho dF llyD onventionl shutdown pprohes re rried out sed on the rule of go to sleep fter the system hs een P he prop osed metho d id le for predenedperiod of timeFroweverD this pE PFI inergy sving using systemEshutdown proh p oses n ovious drwk E the system ontinues tehnique to onsume p ower in tht intervl of idle timeF pigure I depits simple shutdown pproh for y eventEdriven pplitionsF hen the system detets n his work ws supp orted in prt y the xtionl iene idle p erio dD it will determine whether it should styin gounil of FyFgF under qrnt xg VSEPPPIEiEHHUEHQR nd xg the running stte or enter the sleep stteF sf the system VTEPPPIEiEHHUEHPIF 0-89791-993-9/97 $10.00 1997 IEEE ! iY @IA Wake−up s Running Sleep iq a s @i C A Y @PA i a s @i C A @s i AY @QA i Go to sleep a s @ A i @ A Y @RA i i pigure IX e simple shutdown pprohF b HY @SA i @ AC i RI i ab s b @TA R R I R Y @ A delay delay i @ AC i i X @UA ab a th @ A RESWR R EW R ve derivtions indite tht iqnsF I nd U re (a) (b) he o the neessry onditions under whih the idle p erio d will pigure PXwo p ossile senrios when pplying simple hieve energy svingsF e dene s the threshold th systemEshutdown shemeX@A s ! i D@A s i F idle p erio d tht results in energy sving of the systemF deides to enter the sleep stteD the system rst p erforms PFP redition of idle p erio ds num er of housekeeping pro eduresD suh s kingE he nlysis in the previous setion indites tht up dt nd system sttusF he system then stys in prediting the idle p erio d s is vitl for n eetivepower the energyEsving sleep stte until n externl wkeup mngement mehnismF roweverD the distriution nd signl o ursF hen wkeup signl o ursD the system vrition of s my e strongly dep endent on the user eE will p erform reovery pro eduresD suh s dt restoringD hviorD trget pplitionsD working frequenyD nd opE nd then resume the running stteF sf the deision is not erting systemF to enter the sleep stteD the system stys in the running sn our pprohD we dpt the exponentilEverge stte s usy witingF yne of the ruil issues of this pprohV used in the g sheduling prolem for pprohiswhether or not to shutdown the systemD nd the predition of the idle p erio dF sn the g sheduling if so whenc4 so tht p ower dissiption of the system n prolemD op erting systems need to predit the length of e reduedF his issue will e disussed s followsF the next g urst in order to mke pproprite pro ess vet s e the idle time p erio dD i the delyoverhed shedulingF sn generlD the next g urst is predited of entering the sleep stte from the running stteD the s n umultiveverge of the mesured lengths of sleeping time p erio dD nd the delyoverhed for reE previous g urstsF imilrlyDwe n predit the next suming the running stte from the sleep stte @the wke idle p erio d y the umultiveverge of the previous up pro essAF nd re the p ower onsumption vlE idle p erio dsF he reursive predition formul is shown ues of the system in the running nd sleep sttesD resp eE elowF tivelyF is the verge p owerEdissiption overhed i s a i C@I A s Y @VA nCI n n of entering the sleep stte from the running stte nd resuming the running stte from the sleep stteF ypiE where s is the new predited vlueD s is the lst nCI n llyD ! ! F pinllyD iq denotes the energy i predited vlueD i is the ltest idle p erio dD nd is n gin of the systemF onstnt ttenution ftor in the rnge etween H to IF sn this formulD s is the inerti nd i is the fore n n essume tht the system will enter the sleep stte to push the predited idle p erio d towrd the tul idle whenever it detets n idle p erio dF pigure P@A shows p erio dF e n use iqnF V to predit the up oming idle the rst senrio in whih the idle p erio d is longer thn p erio dD whih is funtion of the ltest idle p erio d nd the delyoverhed of entering the sleep stte from the the previous predited vlueF he prmeter ontrols running stte @iFeFD s ! i AF ine s ! i D the system will the reltiveweight of reent nd pst history in the preE suessfully enter the sleep stte nd resume the running ditionF sf a HD then s a s F sn other wordsD the nCI n stte when wkeEup signl o ursF nder this ondiE reent history hs no eetF yn the other hndD if aID tionD the energy gin iq is s @i C A i then s a i F sn this seD the predition only tkes nCI n while the dely p enltyis F pigure P@A shows the seE into ount the most reent idle p erio d ut ignores the ond senrio in whih the idle p erio d is shorter thn the previous preditionsF sn our implementtionD is set to delyoverhed of entering the sleep stte from the runE e IaP so tht the reent history nd pst history re ning stte @iFeFD s i AF sn this seD the system will eqully weightedF e n expnd iqnF V s elowF never enter the sleep stte nd will suer long dely p enlty@del y a C@i sAA nd negtive energy n nCI gin @iq a s @i C A AF reneD in order i s a i C @I Ai C C@I A i C@IA s X nCI n nI H H to hieve energy svingD the idle p erio d must e longer @WA thn the delyoverhed for entering the sleep stte from iqnF W indites tht the predited idle p erio d is the the running stte @iFeFD s ! i AF weighted verge of previous idle p erio dsF irly idle vet us further nlyze the minimum required idle p eE p erio ds hve less weight s sp eied y the exp onentil rio d for hieving p ositive energy gin s followsF ttenution ftorsF I1R1 I2 R2 I3 R3 I4 R4 RIR RIR I3’ I4’ delay (a) RESWR REWS I R I1R1 I2 R2 I3 R3 I’ I’ Busy S waiting (a) (b) I3’ H pigure RX ixmples of preEwkeup mo delX@A s b Sth H D @A s `sF I3’’ s nd h 2 Sth o resolve the seond prolemD we dd sturtion I3’’’ (b) ondition