Title
IMP: indirect memory prefetcher
Abstract
Machine learning, graph analytics and sparse linear algebra-based applications are dominated by irregular memory accesses resulting from following edges in a graph or non-zero elements in a sparse matrix. These accesses have little temporal or spatial locality, and thus incur long memory stalls and large bandwidth requirements. A traditional streaming or striding prefetcher cannot capture these irregular access patterns. A majority of these irregular accesses come from indirect patterns of the form A[B[i]]. We propose an efficient hardware indirect memory prefetcher (IMP) to capture this access pattern and hide latency. We also propose a partial cacheline accessing mechanism for these prefetches to reduce the network and DRAM bandwidth pressure from the lack of spatial locality. Evaluated on 7 applications, IMP shows 56% speedup on average (up to 2.3×) compared to a baseline 64 core system with streaming prefetchers. This is within 23% of an idealized system. With partial cacheline accessing, we see another 9.4% speedup on average (up to 46.6%).
Year
DOI
Venue
2015
10.1145/2830772.2830807
MICRO
Keywords
Field
DocType
indirect memory prefetcher,IMP,machine learning,graph analytics,sparse linear algebra,irregular memory accesses,sparse matrix,non-zero elements,spatial locality,temporal locality,DRAM bandwidth pressure
Dram,Locality,Latency (engineering),Computer science,Parallel computing,Real-time computing,Bandwidth (signal processing),Multi-core processor,Sparse matrix,Branch predictor,Speedup
Conference
ISBN
Citations 
PageRank 
978-1-5090-6601-8
28
0.82
References 
Authors
30
4
Name
Order
Citations
PageRank
Xiangyao Yu127016.17
Christopher J. Hughes298863.34
Nadathur Satish3202099.88
Srinivas Devadas486061146.30