PeerWave
Mehmet Esat Belviranli, Peng Deng, Laxmi Narayan Bhuyan, Rajiv Gupta, Qi Xin Zhu · 2015
Nested loops with regular iteration dependencies span a large class of applications ranging from string matching to linear system solvers. Wavefront parallelism is a well-known technique to enable concurrent processing of such applications and is widely being used on GPUs to benefit from their massively parallel computing capabilities. Wavefront parallelism on GPUs uses global barriers between processing of tiles to enforce data dependencies. However, such diagonal-wide synchronization causes load imbalance by forcing SMs to wait for the completion of the SM with longest computation. Moreover, diagonal processing causes loss of locality due to elements that border adjacent tiles.