文档介绍：UsingHierarchicalSchedulingtoSupportSoftReal-TimeApplicationsinGeneral-Purpose OperatingSystemsJohnRegehrMarch20,20011OutlineMotivationandApproachGuaranteesHLSDesignAugmentedReservationsConclusionsandDemo2OverviewofContributionsAgeneralhierarchyofsoftreal-timeschedulerscanprovideguaranteedschedulingbehaviorTheHierarchicalLoadableScheduler(HLS)architecture…Canbeefficientlyimplementedinageneral-paredtocasewhereschedulerandappsaremismatchedAugmentedCPUreservationsincreasepredictabilitywhentheOSstealsCPUtimefromreal-timeapplications3MotivationPeopleusegeneral-purposeOSs(GPOSs),Windows,modity,convenienceApplicationshavediverseschedulingrequirementsTime-sharingSoftreal-timeIsolationCo-paniessellschedulerextensionsEnsim:ServerXchangeSun:SolarisResourceManagerAurema:ActiveResourceManagementTimeSys:Linux/RT5MotivatingData:UnfairCPUAllocationBetweenUsersUser1getslittleCPUtimewhenUser2createsmanythreadsN1%100N2%:ItisusefulandfeasibletoextendaGPOSwithageneral,:FixedPriorityRES:CPUReservationJ:JoinSFQ:Start-TimeFairQueuing8TimeScalesLong:SystemisusedinaparticularwayDuration:usuallyuptimeofasystemorlongerMedium:Applicationsstart,end,andchangerequirementsDuration:seconds,minutes,orlongerShort:IndividualschedulingdecisionsmadebyschedulerswithinthehierarchyDuration:millisecondsor10sofms9WhatMicrosoftShouldDoPutHLSintoconsumerWindows!BydefaultSupportinteractive,batch,andmultimediaapplicationsforasingleuserHowever,posingthemAPIforimplementingnewschedulers10