1493 - 利用访问模式提高 Java 性能.pdf

1、Orlando,FLOctober 69IBM TechXchange 2025Prof.Kenneth B.KentUniversity of New BrunswickUtilizing Access Patterns to Improve Utilizing Access Patterns to Improve Java Performance 1493Java Performance 1493Utilizing Access Patterns to Improve Java PerformanceCode:1493Hassan Arafat1,David Bremner1,Kennet

2、h B.Kent1,Julian Wang2TechXchange 20251 University of New Brunswick2 IBM CanadaOutline Background Motivation Project Overview Conclusion Future Work3Load Stall MinimizationH.Arafat,D.Bremner,K.B.Kent,J.Wang BackgroundWhat are load stalls and why do they matter?Load Stall MinimizationH.Arafat,D.Bremn

3、er,K.B.Kent,J.Wang 4Processor&Memory Execute instructionsManipulate data Increased instruction throughputHigher frequenciesMore cores StorageInstructions and data Increased speedHigher frequenciesNew technologiesLoad Stall MinimizationH.Arafat,D.Bremner,K.B.Kent,J.Wang 5ProcessorMemoryThe memory wal

4、lProcessor&Memory Performance Gap6Load Stall MinimizationH.Arafat,D.Bremner,K.B.Kent,J.Wang 1101001000100001000001980199020002010ProcessorMemoryAdopted from 1,p.80Consequences of the memory wall7Load Stall MinimizationH.Arafat,D.Bremner,K.B.Kent,J.Wang LookupCPUMemoryProcessor needs to wait for memo

5、ry requestLoad stallCommon mitigation strategies Prefetching:load the data from memory before it is needed.Software:explicit PREFETCH instruction inserted by developer or compiler.Hardware:hardware unit dedicated to detecting common patterns.Out of order execution:Execute other instructions that do

6、not have dependencies on the stalling load.8Load Stall MinimizationH.Arafat,D.Bremner,K.B.Kent,J.Wang Shortcomings Prefetching performs well for constant stride accesses;fails when the pattern is complex or data-dependent.Out of order execution is limited by buffer size and code dependencies.9Load S