Title
ZNN -- A Fast and Scalable Algorithm for Training 3D Convolutional Networks on Multi-core and Many-Core Shared Memory Machines
Abstract
Convolutional networks (ConvNets) have become a popular approach to computer vision. It is important to accelerate ConvNet training, which is computationally costly. We propose a novel parallel algorithm based on decomposition into a set of tasks, most of which are convolutions or FFTs. Applying Brent's theorem to the task dependency graph implies that linear speedup with the number of processors is attainable within the PRAM model of parallel computation, for wide network architectures. To attain such performance on real shared-memory machines, our algorithm computes convolutions converging on the same node of the network with temporal locality to reduce cache misses, and sums the convergent convolution outputs via an almost wait-free concurrent method to reduce time spent in critical sections. We implement the algorithm with a publicly available software package called ZNN. Benchmarking with multi-core CPUs shows that ZNN can attain speedup roughly equal to the number of physical cores. We also show that ZNN can attain over 90× speedup on a many-core CPU (Xeon Phi™ Knights Corner). These speedups are achieved for network architectures with widths that are in common use. The task parallelism of the ZNN algorithm is suited to CPUs, while the SIMD parallelism of previous algorithms is compatible with GPUs. Through examples, we show that ZNN can be either faster or slower than certain GPU implementations depending on specifics of the network architecture, kernel sizes, and density and size of the output patch. ZNN may be less costly to develop and maintain, due to the relative ease of general-purpose CPU programming.
Year
DOI
Venue
2015
10.1109/IPDPS.2016.119
2016 IEEE International Parallel and Distributed Processing Symposium (IPDPS)
Keywords
Field
DocType
Convolutional Neural Networks,Deep Learning,Backpropagation,Many-Core and Multi-Core Parallel Algorithms,FFT Convolution,Wait-free Parallel Summation
Locality of reference,Shared memory,Xeon Phi,Parallel algorithm,Computer science,Task parallelism,Parallel computing,SIMD,Multi-core processor,Speedup
Journal
Volume
ISSN
ISBN
abs/1510.06706
1530-2075
978-1-5090-2141-3
Citations 
PageRank 
References 
11
0.87
15
Authors
3
Name
Order
Citations
PageRank
aleksandar zlateski1395.65
k lee2110.87
H. Sebastian Seung31791288.80