The Queue-Read Queue-Write PRAM Model: Accounting for Contention in Parallel Algorithms

This paper introduces the queue-read, queue-write (qrqw) parallel random access machine (pram) model, which permits concurrent reading and writing to shared memory locations, but at a cost proportional to the number of readers/writers to any one memory location in a given step. Prior to this work there were no formal complexity models that accounted for the contention to memory locations, despite its large impact on the performance of parallel programs. The qrqw pram model re ects the contention properties of most commercially available parallel machines more accurately than either the well-studied crcw pram or erew pram models: the crcw model does not adequately penalize algorithms with high contention to shared memory locations, while the erew model is too strict in its insistence on zero contention at each step. The qrqw pram is strictly more powerful than the erew pram. This paper shows a separation of plgn between the two models, and presents faster and more e cient qrqw algorith...

• Type: Journal
• Year: 1998
• Where: SIAMCOMP
• Authors: Phillip B. Gibbons, Yossi Matias, Vijaya Ramachandran
• Keywords: Memory Locations, Pram Models, Qrqw Pram, SIAMCOMP 1998