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Predictability of just in time

De
48 pages
Niveau: Supérieur, Master
Predictability of just in time compilation Adnan Bouakaz Supervisors : Isabelle Puaut, Erven Rohou IRISA, ALF project Research Master's degree in Computer Science June 2010 du m as -0 05 30 65 4, v er sio n 1 - 2 9 O ct 2 01 0

  • lru system

  • virtual machines

  • platform

  • virtualization can

  • many

  • machine code


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SciencePredictproabilitynofMaster'sjustErvinIRISA,timeResearccompilaintion2010AednanRohouBouakALFazjectSuphervisorsdegree:ComputerIsabJuneellePuaut,
dumas-00530654, version 1 - 29 Oct 2010.Con.ten.ts.1.JIT2.6Compilation.&.W.CET.Estimation.4.1.13.1Virtual.Mac.hines....2...BFIF...............Determination...39.............................o.........erimen.Case4.1.2.JIT.Compilation..........Analysis.........ersp...........U.............25.System...................La.t6.1.3.W.CET.Estimation.Metho.ds....3.Results.v.erformance...............3.2.................Cac..............8.1.4.Predictabilit3.4yesof.HLL.VMs.&.JIT.Compilation........3.LR.System........................11.22.5PredictabilitOy.of.the.JIT.Compile.r.Launc.hing.14.2.1.Bac.kgro.u.nd..........28.Fixed.y.u.System.................................33.Exp.tal.38.A.erage.P............15.2.2.Problem.Statemen.t.and.Ass.umptions....38.Conicts.................................3.3.he......1.9.2.3.Fixed-Size.Blo.c.ks.wi.th.LR.U.System........40.P.ectiv....................................20.2.44BinaryBuddywith
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canJITsuppCompilationso&WindoWoCETotherEstimationaThishines:cyhaptereinIsolationtroelopducemactcesseswsystemoPIlargelyVMsdierenatordomains.macFirst,forthewboenetsyoftvirtualizationmacandanJITexistcompilationplatform).aresamelistedvirtualinfor?k1.1Fanddesigning?lev1.2of;alsothenatibilityavidesbriefwsurvoneyabstractiononthWmacCETtestimationsoftmerealtharcodsds]:isVpresenttedandinple?in1.3on.isolatedWcaneplatform.concludeVMtheIncterface)haptertions.bulationyeaskingpaortabilrelevhievanstoquestion:4Whatnecessarilyisi.e.neededdetails.tovidesrecomomthebine(VM)thcompatibleealltrewwillot,domainsthetotheexrunningpVMloitandtheirines.resplemectivVM,eaddadvareantotages?hine1.1theVirtualThereMacohinesfAlthough[noSystemwAadaproysencomputerwhicseratingyystemsmarecanvVirtualehrysystemcomplex,Macintheymancoponvironmentinonuehardwtovirtualevproolvvidese.(ApplicationTheyorareProgrammingdesignedvironmenasaphierarccesshiesreplication,ofoptimization.dierenobtprolevtheelsyofcross-platformabstractionyseparatedebbyprowVMell-denedofinerallterfalanguageces.nEacththoseabstractionabstraction,hidessimplifyingahidinglargeItamounprotSoftwarocfpimp:lemvirtualenhinetationprodetails.aInabstraction[that31soft],awwritteneitcanrunndiexamplesandof:sucVMhisolatesabstractions.softFareorininstance,ecomputer'fromsVMsinstructionrealsetharcThitectureimp(ISAen)aisdevaersniceaexamplewoflatheerwaell-denedmacintoterfaces.ortUnfortunatelydesired,hitecture.subsystemsareandwcompkinonenotsvirtualdesignedhinesfor31oneChapterinvirtualterfacehines:willsystemnotMwvidesorkcompletewithvironmenthoseindesignedhforopanothersystem(i.e.mananprointerofopultierusersabilitycoproblem).(e.g.VirtualizationPCprowhicvidesaawswrunsaaytoshtoSo,gettingyaroundguestsuceratinghenproblems.tsVirtualizingrunathesystemhostorare1PrococessmpmaconenAtcess(sucprohaasABIaBinaryproterface)cessor,Amemory(Application.In.en.t)useratplica-aProgivVMsenoerabstractionemlevandelAmapseyitsjectivinforterfacecessandisvisiblecross-platformresourcesortabiliton.toullthepinitterfacemaabnacdedresourcesyofaanceunderlying,spasossiblypartdierenant,vrealhigh-system.elVirtualization(HLL)goalsare
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dumas-00530654, version 1 - 29 Oct 2010inCHAPTERshould1.,JITbinaryCOMPILAseparateTIONIT&runningWthoseCETincludesESTIMAstate.TIONjudges6tonativcoeocoddethecompilationJafortor,thetime:Jadescribvbanot,platformuinsomesucnhtheavwbutahayithe[pseparatedortabilitinymono-prisloadernotorsthastatecriced.wiTheatrstJVMtecvironmenhniquetranslatedtorunningexploremethoishtheinAtheheinadyofenstimedetracnaslationalready(Ade.OT).tiThemanageprinciplecibdeatecisetoistranslateecutingallWprogramabcompiler.ytecoarcdescomptogarbagemacahineycofromdestatesbJITeforecoexehangecucompilertion.wsAofbstateigthecinitializeshallengeaofdsucehJITtechangedhniqueoristhethenativdynamictrclassvloading.methoAerfoclasscollector),canneothem.tplbwitheprice.loadedtimeunestilthethespexecuting.cosituationdecompiler.mak6escoabreferenceJITtocompilthnaetcclass.oBecause.AaOTwowccursniquesb].eforestatictheproprogramenexecutes,thethencompilerJITcannotcanmak36eofanayorassumptionscabtheoutmwhicts:hlinkclassesollhmanageracompiler.vtationewbJITeenJVM,loaded.areAnotherrutecMhniqueompiisnativtherunnjust-instatetimethe(JIT)acbompiaslation1.2inbwhicehrunnitheinrstandtimeleaexecuted,methorunningdBeforeisd,calledtheitbistotranslatedde.incallstoandobisjecttocostate.dea(seecalling?compiler1.2generate).instructionWitselfeolinecanthendmethoinnativ[F21ctions]ba(e.g.detailedJITcomparisonthebwhicetokwChallengeseencompilationthetformAmainOTcompilation,andatthecompilationJITthecompilationprogramtecithniques.compileTheaddedfourthrotecTherefore,hniqueisisatheishardwdierenarethatVM:tional,aoproerhead,cessorwiththatcompiledimpldeewithmenytecotsBoththeandJVMdynamicinstruc-ationoset.sAsvantoexaample,ompilethecJadevacheaThereoptismcomparisonietzeenedtproocessorh(JOP)in[830Unlik].aJOPcompiler,iscompilingacedurestacnotktirelycomputerfromwithex-itsooewnainstrucompiler.ctioneset,ndcalled[micro]codesignde.aJavvJITaFbaytecoodesessorarehitecture,translatedJVMinfourtoainmicroonencoclassdandeer,instructionscorecsequencesthreadofandmicroJITcoFdpreseneclaritin,hardweare.theThiscompilertecthehniquesoremoerevthreeesatthenoJVvstate,erheadcoflingdecoanddiengdeinstruingctionsTheincsoftinwJVMare.thItJITdocanesenot,edhofollow(Figureev):er,theaddresseginningthetheproblemxecutionothefngpisortableJVM.executionloadsonlinksexistingclassprotocessors.e1.2andJITtheCompilaentt.ioexecutingnmethoInJVMterpretinifgmethobhasytecoeendesininativscosloIfw.JVMPtheerformingcompilercompilationthepriorstatetocrunintimeJandcompilingloadingFthetranslatingprogramJVMasdnativinstruction,eJITcomdestwaouldeeliminatewhicthecallsp(aortabilampit)ytranslateandJasecuritaydoftoJaevd.aorprograms.funOnpthermedothyeJVMrgarbagehand,thecompilingcompileratgeneraterunnativtimeinstructionspreservhesvtheseeimp1.2.1ortanitJITpropAlthougherties.aTheneutralitprogramiscantainedstillJITbitemesdistributedainBecauseplatform-indephappendenattsameclassasles,execution,andtimethetakbtoytecocodesiscantostillpbgram'setime.vcompilationeriedeedpriorcrutoicompilation.lSoThisuanlikeryetbinaryfromdynamicfacingcompilation,tradithestaticproTcessminimizedovesnotstart
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7COMPILAspTIONt&elyWyCETerformanceESTIMAATIONsp7inFigurecess1.2:mThehoJVM'sitstatebasedcsimplehangezwareethatcanMorea7veoidadvcompilioptimizationngtheacompilermethothedcompileunatilditself-monitoring,isdcertainendthatsomeittowillthebbeopexecuted.theComparedetointraditionalsubstanstaticfucompilers,tionJITtocompilers]:plikerformathetimesamemethobasicthetaskolingofegeneratingisnativedebcoede,exbutterpretedatemters,ucmethohoffastersystemrate.itsThesed.cytecohallengeestforhineabinationJITytecocompilertheirJITisdestoredundanndrationwabacompilationysytoingenerate1.2.2eciencompilerstcompilerscoimprodeerformance,withoutJVMincurringlementheuseexptecensefurtherof[traditionaldaptivowptotimizationtotecdhniques.tInprogrammaninyAcoobservmpimlers,(constructingandanfrequeninmotermeedwheniateonrepresenfrequencies.tationobserv(IR)viorisofaInstandardsystem,protionscess.areTheusebcompiler.ytecodedesexecutioncandetectbWheneistheorthIRmfor,theanJITtimecompiler.pHouwIndeed,evber,desratherbthantranslatedtreatingmacbinstructionsytecocomdeswithasbliteraldesdescriptiuseoresults.nThesytecoofmatheincludecotdeetos.bdetailseoutexecuted,JITaproJITmacanbusefoundthem[as].implicitOptimizationencoJITdingsCurrenofJITexcanptiallyressions.vTherepareandthreeturemaijorpissuesta-awillsmoresoancedciatedhniqueswithrealizetransformingpbgainsyteco7desAdirectlyeinOnetoouldecienettailormacwhinecompileinstructions:metho1.toTheamounuseofofthetheactuallyopendserandthatstacd.kdynamicconstrainscantheeoprogrardaserrunsofprev)aluationoptimizespmosteciedtlybxecutedydels.thesimplbexampleyte-decidingcotodes.basedMoreobservecienexecutiontRecompilingorderingsoncouldedbehaeispformossibleadaptivwithoptimization.aadaptivregister-basedoptimizationproinitialcessor.ecuCHAPTERofamethoTheeitherbinestorcahoicefastofThmaccohineisinstructionusingforcounatoparticularhotbots.ytecoadedmafounywdepyendoptionihoationwtheacresultspofmorethatonbcomytecoilation.deis
dumas-00530654, version 1 - 29 Oct 2010real-timeCHAPTERwill1.obtainsJITimpCOMPILAtoTIONwhole&system,WonCETmESTIMAoTIONfo8willThisitapproacyhUnfortunatelyusesguarantmethowtheoStaticdynamicacompilers,areaitfastinnon-optimizingAcompilerdeadlinandmissateesecondacoptimizingExecutioncompiler.inTheuseauthorsterminate;offor[duce17(are]tdiscusstaskthedoutilittheymoofomo-linedeproleJITinformationnototialdecidetemwhicthehiscompilermissiontoousenormalinitiallyIn.bTheyesdevsituations.elopitedwanofannotationnotframewupporkprograms,toofcommalwuni-iscatewthatainformation(dowioundsthandthebJITIncompiler.familiesAnWo[thclasseronware,orkand/orinbines[system's18ounds]reppresenterestedtswaimpactstudWythatofcowhetherJITside-eectstaticinformation8collectedoralo-lineauimprotovreal-timeessystempierformanceeninareJIT,compilers.dAerationdaptivyehardinliningmInliningamethoitdsmiss(replacingincallsorderwithetheofatoctuWa(Wlhcoitdeossibloftothebcalledtimesmewthrestrictedowhicds)thatisyanwhicicasemThepmainortanaluatintCEToptimizationare:initaneryexecutionprogramorwitheaupphighclosecallWdensitsection,yoandmethosmalloundmethoofds.presenThe].usedsofmethovirtualnotcallscoinrealJaitvcoadefeatsexecutable,traditionalwithinlininofgare,tecerhthisniques,Inbwecauseeciallymansourceybtargettrymethoindsvirtualizationmaonyestimation;existobforereaobvforiinrtualThecall.ofAaredynamic1.3compilerthecanpinlinedomainevcenseasystemvirtualfail.callsoftwithsystemmoreapthatotefulllntstialevtargets.ifTheesrunmissedtimeccasionallysystembutcanshoulnoteincallopsnotitesanwhicdeadline.hainreal-timevthereokusteethguaranethatsamedomethonotdanrepdeadlineeatedlyall.InThetocompilerhievcanthis,alsoisemitvitalsportanceecialiknozethedorst-CasevTimeersionCET)seacoftask.the,methoisd.p1.3e,Wgeneral,CETobtainEstimationerMethooundsdsexecutionUnfortunatelyfor,unlessHLLeVMsaareformnotprogrammingwidesphreteesadprogramsinareal-timessystemsandforhatheninumsystems.bteroofcriteriasignicanevtgreasonsW(seeestimation?d1.4safety)eswhicprohuppmainlybconcernoftheirtiunesabilitnot?)yprofcisionvthealidatingertimingoundsconstraintots.actualBut,CET?)theythisremaintheawtargetmainsolutionoffordsthebproblemtheoCETfathearefragmentedtation34of1.3.1platformsMethoforThisemofbdseddedessystems.relyIndeed,executingthedebnytecohardwdebutisanalyzesansourceedeectivtheendeplolymencomtitformatsomefordelemthebhardweddedandsystemsuppandbsofromforcreal-timebination.systemthis[ort,4e].espTheinsuccessinofcoreal-timeanalysissystemsecauserelieseuptooncustheirthecapabilitofyandofcompilationprotheducingCETfunctionallyandcorrectisresultsviouswithinthdenedistiminggeneratedconstrainjectts.deAthehartaskdareal-timecompilation.systemessenisstepsathesystemanalysiswhdepictedereFigurea.failurein
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dumas-00530654, version 1 - 29 Oct 2010

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