EQUALS --- The Next Generation

Owen Kaser, C. R. Ramakrishnan, R. Sekar


EQUALS is a system for parallel evaluation of lazy functional programs implemented on a Sequent Symmetry. A preliminary implementation of EQUALS was used to establish the validity of Normal Form (NF) demand propagation and memory reclamation via reference counting. However, that implementation did not exploit vertical parallelism, where the arguments to a function can be evaluated in parallel with the function itself. The overheads of vertical parallelism can be as high as the overheads in systems that do not propagate NF demand. Hence careful integration of vertical parallelism with horizontal parallelism (parallelism among the arguments to a function) is needed to fully benefit from NF-demand propagation. In this paper we describe schemes to harness vertical parallelism within the context of the current EQUALS system. We identify the aspects of the runtime system (task management) that affect the overall efficiency of the combined system. We also provide preliminary performance figures indicating the effectiveness of the selected schemes.

Bibtex Entry:

author = {Owen Kaser and   C. R. Ramakrishnan and   R. Sekar},
title = {{EQUALS} --- The Next Generation},
booktitle = {International Workshop on Parallel Processing},
pages = {615--620},
publisher = {Tata McGraw Hill},
year = {1994}

Full Paper: [pdf]

Home | Papers

C. R. Ramakrishnan