高级计算机体系结构设计及其在数据中心和云计算的应用Lecture 9Control Flow Transfer in Java Processing:Characterization and Architectural Implications
高级计算机体系结构设计及其在数据中心和云计算的应用 Lecture 9 Control Flow Transfer in Java Processing: Characterization and Architectural Implications
高级计算机体系结构设计及其在数据中心和云计算的应用Control Flow Transfer in Modern ProcessorsProblem:pipelinestallSolution:prediction, speculative executionAccuracyof predictionisveryimportantTo improveaccuracyof predictionforemergingworkloads: characterization is the first stepSelectedJavaduetoitspopularityinembeddedtoserverplatforms
高级计算机体系结构设计及其在数据中心和云计算的应用 Control Flow Transfer in Modern Processors • Problem: pipeline stall • Solution: prediction, speculative execution • Accuracy of prediction is very important • To improve accuracy of prediction for emerging workloads: characterization is the first step 2 – Selected Java due to its popularity in embedded to server platforms
高级计算机体系结构设计及其在数据中心和云计算的应用Java ProcessingJavaPrograms(Bytecode)ClassLibrariesClassLoading&I/ORMIawtnetVerificationJVMJITCompilerInterpreterNativeJavaGarbageCodeThreadManagementNativeCollectionInterfaceOperating SystemHardwarePlatform
高级计算机体系结构设计及其在数据中心和云计算的应用 Java Processing Java Programs (Bytecode) Class Loading & Verification awt net I/O RMI . Class Libraries JVM 3 Interpreter . . . JIT Compiler Garbage Collection Thread Management Native Code Java Native Interface Operating System Hardware Platform
高级计算机体系结构设计及其在数据中心和云计算的应用MajorFeaturesof JavaMajorrun-timefeaturesofJavaarisefromeither-Javaruntime environment:Java Virtual Machine (JVM)-Interpreter-JustInTime (JIT)compiler. Garbage collection, synchronization,class loading etc.Javalanguagefeatures(Objectorientedness,classesvirtualmethodsetc.)
高级计算机体系结构设计及其在数据中心和云计算的应用 Major Features of Java • Major run-time features of Java arise from either – Java runtime environment • Java Virtual Machine (JVM) – Interpreter – Just In Time (JIT) compiler • Garbage collection, synchronization, class loading etc. 4 – Java language features (Object orientedness, classes, virtual methods etc.)
高级计算机体系结构设计及其在数据中心和云计算的应用OsActivity inJavaProcessingSPECjvm98:4%~17%[ICS'00]Java Servers:65.3%[Luo etal.,ISPASS'01]SPECInt95:<2%[ICS'00]OSActivityinSPECivm98%ofosCycleBenchmarks4.3compress14.9jessdb12.614.9javac8.6mtrtjack16.9
高级计算机体系结构设计及其在数据中心和云计算的应用 OS Activity in Java Processing • SPECjvm98: 4%~17% [ICS’00] • Java Servers: 65.3% [Luo et al., ISPASS’01] • SPECInt95: <2% [ICS’00] OS Activity in SPECjvm98 Benchmarks % of OS Cycle 5 compress 4.3 jess 14.9 db 12.6 javac 14.9 mtrt 8.6 jack 16.9