The final publication is available at ACM via http://dx.doi.org/10.1145/3392717.3392762 Wavefront Parallelization of Recurrent Neural Networks on Multi-core Architectures Robin Kumar Sharma Marc Casas Barcelona Supercomputing Center (BSC) Barcelona Supercomputing Center (BSC) Barcelona, Spain Barcelona, Spain
[email protected] [email protected] ABSTRACT prevalent choice to analyze sequential and unsegmented data like Recurrent neural networks (RNNs) are widely used for natural text or speech signals. The internal structure of RNN inference and language processing, time-series prediction, or text analysis tasks. training in terms of dependencies across their fundamental numeri- The internal structure of RNNs inference and training in terms of cal kernels complicate the exploitation of model parallelism, which data or control dependencies across their fundamental numerical has not been fully exploited to accelerate forward and backward kernels complicate the exploitation of model parallelism, which is propagation of RNNs on multi-core CPUs. the reason why just data-parallelism has been traditionally applied This paper proposes W-Par, a parallel execution model for RNNs to accelerate RNNs. and its variants LSTMs and GRUs. W-Par exploits all possible con- This paper presents W-Par (Wavefront-Parallelization), a com- currency available in forward and backward propagation routines prehensive approach for RNNs inference and training on CPUs of RNNs. These propagation routines display complex data and that relies on applying model parallelism into RNNs models. We control dependencies that require sophisticated parallel approaches use ne-grained pipeline parallelism in terms of wavefront com- to extract all possible concurrency. W-Par represents RNNs forward putations to accelerate multi-layer RNNs running on multi-core and backward propagation as a computational graph [37] where CPUs.