Improving compiler and run-time support for adaptive irregular codes
Hwansoo Han, Chau‐Wen Tseng · 1998
Irregular reductions form the core of adaptive irregular codes. On distributed-memory multiprocessors, they are parallelized either using sophisticated run-time systems (e.g., CHAOS, PILAR) or the shared-memory interface supported by software DSMs (e.g., CVM, TreadMarks). We introduce LOCALWRITE, a new technique based on the owner-computes rule which eliminates the need for buffers or synchronized writes but may replicate computation. We evaluate its performance for irregular codes while varying connectivity, locality, and adaptivity. LOCALWRITE improves performance by 50--150% compared to using replicated buffers, and can match or exceed gather/scatter for applications with low locality or high adaptivity. 1 Introduction Scientists are beginning to exploit parallelism to provide the computing power they need for research and development. As they attempt to model more complex problems, irregular adaptive computations become increasingly important. The core of these applications is fre...