PDF-Multiprocessor Cache Coherency

1 1 CS448 2 What is Cache Coherence x2022 Two processors can have two different values for the same memory location Write Through Cache 2 3 Terminology x2022 Coherence x2013 Defines what va. Client sends HTTP request 2 Web Cache responds immediately if cached object is available 3 If object is not in cache W eb Cache requests object from Application Server 4 Application Server generates response may include Database queries 5 Applicatio Message Passing Sharedmemory single copy of shared data in memory threads communicate by readingwriting to a shared location Messagepassing each thread has a copy of data in its own private memory that other threads cannot access threads communicate coprocessor 8087 2 closely coupled 8089 3 loosely coupled Multibus Coprocessors and closely coupled configurations are similar in that both the CPU and the external processor share Memory IO system Bus bus control logic Clock generator Closely Autumn 2006 CSE P548 Cache Coherence 6 A Lowend MP brPage 4br Autumn 2006 CSE P548 Cache Coherence 7 Cache Coherency Prot ocol Implementations Snooping used with lowend MPs few processors centralized memory busbased distributed implementation S. Narravula, P. Balaji, K. Vaidyanathan, . S. Krishnamoorthy, J. Wu and D. K. Panda. The Ohio State University. Presentation Outline. Introduction/Motivation. Design and Implementation. Experimental Results. Hakim Weatherspoon. CS 3410, Spring 2013. Computer Science. Cornell University. P&H Chapter . 2.11 and 5.8. Big Picture: Parallelism and Synchronization. How do I take advantage of multiple processors; . UC Berkeley Seismological Laboratory. Towards Optimal Design of Seismic Array For Earthquake Source Imaging . Pablo . Ampuero. Caltech . Seismo. Lab. Yellow Knife Array. (. Rost. & Thomas ,2002). Multiprocessor Hakim Weatherspoon. CS 3410, Spring 2013. Computer Science. Cornell University. P&H Chapter 2.11 and 5.8. Big Picture: Parallelism and Synchronization. How do I take advantage of multiple processors; . Companion slides for. The Art of Multiprocessor Programming. by Maurice Herlihy & Nir Shavit. Art of Multiprocessor Programming. 2. Shared-Memory Computability. Mathematical model of . concurrent. Companion slides for. The Art of Multiprocessor Programming. by Maurice Herlihy & Nir Shavit. Art of Multiprocessor Programming. 2. A Shared Pool. Put. Insert item. block if full. Remove. Remove & return item. With a superscalar, we might need to accommodate more than 1 per cycle. Typical server and . m. obile device. memory hierarchy. c. onfiguration with. b. asic sizes and. access times. PCs and laptops will. Recall: Microprocessors are classified by how memory is organized. Tightly-coupled multiprocessor systems use the same memory. They are also referred to as . shared memory multiprocessors. .. The processors do not necessarily have to share the same block of physical memory: . Direct-mapped caches. Set-associative caches. Impact of caches on performance. CS 105. Tour of the Black Holes of Computing. Cache Memories. C. ache memories . are small, fast SRAM-based memories managed automatically in hardware.