资源描述：
《evaluating dynamic prefetching in a software dsmnew》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、EvaluatingDynamicPrefetchinginaSoftwareDSMXinghuaAnTingLiuCarnegieMellonUniversityPittsburgh,PA15213{anxh,tingliu}@cs.cmu.eduAbstractWhilesoftware-controlledstaticprefetchinginsoftwareDSMsappearstoachievegreatperformanceonmanyapplications,theresultsininvesti
2、gatingprefetchingwithruntimeinformationarenotsatisfiedduetotheformidableoverhead.Seekingspecificprefetchingmechanismstoreducetheexecutiontimeofacertainkindofapplications,however,isapromisingworkandwillimpactonSVMsandotherfields.Inthisreport,anexperimentalwor
3、k,addingdynamicprefetchinginJIAJIA,asoftwareDSMbasedonscopeconsistency[Pal96],hasbeenproposedandevaluated.Therearetwofeaturesinourprefetchingalgorithm:it’ssensitivetostrideaccesspatternandcanbecombinedintoJIAJIA’slock-basedcoherencyprotocolwithoutmuchmodific
4、ation.Thetestresultsshowthatithashighpredictionaccuracyandachievesgoodoverlapbetweencommunicationandcomputationinbenchmarkapplications.Thisworkgivesagoodproofthatstudyonsoftware-baseddynamicprefetchingisreasonable,promisingandworthtomakefurthersteps.1Introdu
5、ctionOverthepastdecade,softwareDistributedSharedMemory(DSM)systemshavebeenextensivelystudiedtoprovideagoodcompromisebetweenprogrammabilityofsharedmemorymultiprocessorsandhardwaresimplicityofmessagepassingmulticomputers.InDSMsystems,physicalmemoriesofmultiple
6、workstationsarecombinedtoformalargersharedspace.ManycurrentsoftwareDSMsystems,suchasIvy[Li88],Midway[Bershad93],Munin[Carter91],TreadMarks[Keleher94],andCVM[Keleher96]havebeenimplementedonthetopofmessagepassinghardwareoronnetworkofworkstations.Communicationl
7、atencyisgenerallymuchlargerinaDSMsystemthanitwouldbeinamultiprocessorsystem,andbandwidthgenerallymuchlower.Thisleadstodifferentdesigndecisionsinareassuchasmemoryconsistencyandcachecoherencewheretheincreasedlatencyincreasesthecostofoperations.Severalrelaxedme
8、moryconsistencymodels,suchasreleaseconsistency(RC),lazyreleaseconsistency(LRC),andentryconsistency(EC)havebeenimplementedinsoftwareDSMsystemstoreducecommunicationlatency.JIAJIAimplementsthescope
