Download or read book Analysis of memory access dependencies in shared memory multiprocessors written by M. Dubois and published by . This book was released on 1988 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scalable Shared Memory Multiprocessors written by Michel Dubois and published by Springer Science & Business Media. This book was released on 1992 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mathematics of Computing -- Parallelism.
Download or read book Reducing Memory Access Delays in Large scale Shared memory Multiprocessors written by University of Illinois at Urbana-Champaign. Center for Supercomputing Research and Development and published by . This book was released on 1992 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Memory access time is a key factor limiting the performance of large-scale, shared-memory multiprocessors. In such systems, limited bandwidth in the interconnection between the processors and the memories, coupled with long delays resulting from network and memory conflicts, can produce serious memory access delays. Incorporating memory hierarchies and asynchronous block transfer mechanisms are common methods for reducing these delays. However, for these two mechanisms to be wed advantageously, they must be managed effectively, either in hardware or in software. Although this memory management problem is becoming increasingly important, good techniques are still lacking. The problem of reducing memory access delays can be attacked at several levels. The first is to attempt to improve the performance of the shared-memory system itself, where the shared-memory system includes implicitly both the network and the memory modules themselves. The second is to develop techniques to manage the memory hierarchy more effectively and to make use of the block transfer mechanisms. This thesis addresses this problem at both of these levels. The first part examines the behavior of a realistic shared-memory system and evaluates cost-effective hardware modifications for improving this balance. An additional goal is to achieve memory system scalability, where the term scalable describes systems whose per-processor performance is roughly constant across the range of system sizes examined. The remainder of this thesis addresses the problem of improving utilization of local storage in shared-memory systems where, at the very least, each processor has access to local (private) storage in addition to the global (shared) memory. A combined flow-and-dependence analysis algorithm is developed which produces the analytical information needed to optimize data accesses. It is shown how this information can be used as part of an intergrated hardware/software approach to eliminating redundant (unnecessary) memory accesses and prefetching data.
Download or read book Analysis of Shared Memory in Multi core Systems written by Jaya Chaitanya V S L V N and published by . This book was released on 2015 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a multi-core system, the memory hierarchy and the interconnection network play a dominant role in deciding the performance of the system. In this research, we analyze the dependence of system performance on the interconnection network and memory hierarchy using a set of scientific and engineering workloads. A configuration with a smaller network has low memory access latency, but is more susceptible to memory access conflicts due to fewer memory banks. The extra delay originated from the concurrent memory access conflicts may offset the benefit of shorter latency. So, in this case a larger network with more number of memory banks can benefit from high number of concurrent memory access. This analysis reveals an important tradeoff between employing different sizes of network. Cache sharing on a multi-core processor is usually competitive. Cache coherence problems associated with private caches and the improvement in performance with sharing is analyzed in the last chapter.
Download or read book Analysis of Shared Memory Misses and Reference Patterns written by Jeffrey B. Rothman and published by . This book was released on 1999 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "Shared bus computer systems permit the relatively simple and efficient implementation of cache consistency algorithms, but the shared bus is a bottleneck which limits performance. False sharing can be an important source of unnecessary traffic for invalidation-based protocols, elimination of which can provide significant performance improvements. For many multiprocessor workloads, however, most misses are true sharing and cost start misses. Regardless of the cause of cache misses, the largest fraction of bus traffic are words transferred between caches without being accessed, which we refer to as dead sharing. We establish here new methods for characterizing cache block reference patterns, and we measure how these patterns change with variation in workload and block size. Our results show that 42 percent of 64-byte cache blocks are invalidated before more than one word has been read from the block and that 58 percent of blocks that have been modified only have a single word modified before an invalidation to the block occurs. Approximately 50 percent of blocks written and subsequently read by other caches shown no use of the newly written information before the block is again invalidated. In addition to our general analysis of reference patterns, we also present a detailed analysis of false sharing and dead sharing in each shared memory multiprocessor program studied. We find that the worst 10 blocks from each our traces contribute almost 50 percent of the false sharing misses and almost 20 percent of the true sharing misses (on average). A relatively simple restructuring of four of our workloads based on analysis of these 10 worst blocks leads to a 21 percent reduction in overall misses and a 15 percent reduction in execution time. Permitting the block size to vary (as could be accomplished with a sector cache) shows that bus traffic can be reduced by 88 percent (for 64-byte blocks) while also decreasing the miss ratio by 35 percent."
Download or read book A Tool for the Static Dependency Analysis of Shared Memory Parallel Programs and the Implications for Trace driven Simulation written by Doreen Yen and published by . This book was released on 1993 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Analysis of a Shared Memory Multiprocessor written by Robert Tod Dimpsey and published by . This book was released on 1987 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design and Analysis of High Performance Cache Memories for Shared Memory Multiprocessor Systems written by Gunjan K. Sinha and published by . This book was released on 1991 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Analysis of Cache Coherence Protocols in Shared Memory Multiprocessor Systems Under Generalized Access Environments written by Ramachandran Subramanian and published by . This book was released on 1996 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Evaluation of Shared Memory Multiprocessing Architectures written by Hong Jiang and published by . This book was released on 1991 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hot Spot Analysis in Large Scale Shared Memory Multiprocessors written by Karim Harzallah and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "Scalable multiprocessors that support a shared-memory image to application programmers are typically based on physical memory modules that are distributed. Consequently, the access times for a particular processor to various parts of physical memory differ. In this paper, we explore the implications of this non-uniformity in memory access times. In particular, we study the effect of hot-spots in hierarchical large scale NUMA multiprocessors. Hot-spot analysis is of interest because coordinated threads of parallel programs lead to hot spots whose impact on performance may be substantial or even dominant. We have developed an analytical model of access latencies and contention for shared resources in the interconnection network that links the processors and memory modules. Our objective is to provide a better understanding of non-uniform memory access times in scalable architectures. We show the extent to which a variable can be shared before it becomes a performance bottleneck, and assess the potential gain from replication of shared data items. We also demonstrate that the backoff value (after a memory request rejection) must be chosen carefully to balance memory access time and network utilization. Finally, we show that memory utilization is improved by allowing memory request buffering."
Download or read book Compiling for Distributed Memory Multiprocessors Based on Access Region Analysis written by Yunheung Paek and published by . This book was released on 1997 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Analysis of the Interactions of Overhead reducing Techniques for Shared memory Multiprocessors written by University of Wisconsin--Madison. Computer Sciences Dept and published by . This book was released on 1995 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "The fine-grain nature of shared-memory multiprocessor communication introduces overheads that can be substantial. Using the Scalable Coherent Interface (SCI) as a base hardware platform and the SPLASH benchmark suite for applications, we analyze three techniques to reduce this overhead: (i) efficient synchronization primitives, and in particular a hardware primitive called QOLB; (ii) weakened memory ordering constraints; and (iii) optimization of the cache-coherence protocol for two nodes sharing data. We perform simulations both for current technology and technology that we anticipate will be available five years hence. We find that QOLB (of which this study performs the first detailed simulations) shows a large and consistent improvement, much larger than that predicted by Mellor-Crummey and Scott [19]. The relaxation of memory ordering constraints also provides a consistent performance improvement. In accordance with prior results, we show that a more aggressive memory model produces more substantial performance improvements. The optimization for two-node sharing shows mixed results, correlating unsurprisingly with the presence of that sharing pattern in an application. Our most important results are (i) that the overheads eliminated with these optimizations are largely orthogonal -- the performance gains from supporting multiple optimizations concurrently are for the most part additive -- and (ii) that technological improvements increase both these overheads and the success of the optimizations at reducing them."
Download or read book Modeling and Analysis of Scalable Reader writer Locks for Shared memory Multiprocessors written by Baohua Wang and published by . This book was released on 1995 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cache Memory Design and Performance Issues in Shared memory Multiprocessors written by Farnaz Mounes-Toussi and published by . This book was released on 1995 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive and Integrated Data Cache Prefetching for Shared memory Multiprocessors written by Edward H. Gornish and published by . This book was released on 1995 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hardware and Compiler Support for Cache Coherence in Large scale Shared memory Multiprocessors written by Lynn Choi and published by . This book was released on 1996 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
