A Tighter Analysis of Work Stealing

Abstract. Classical list scheduling is a very popular and efficient technique for scheduling jobs in parallel platforms. However, with the increasing number of processors, the cost for managing a single centralized list becomes prohibitive. The objective of this work is to study the extra cost that must be paid when the list is distributed among the processors. We present a general methodology for computing the expected makespan based on the analysis of an adequate potential function which represents the load unbalance between the local lists. A bound on the deviation from the mean is also derived. Then, we apply this technique to show that the expected makespan for scheduling W unit independent tasks on m processors is equal to W/m with an additional term in 3.65 log2 W. Finally, we analyze the work stealing algorithm of Arora, Blumofe and Plaxton and significantly improve the bound on the number of steals. Moreover, simulations show that our bound is very close to the exact value, ap...

• Type: Journal
• Year: 2010
• Where: ISAAC
• Authors: Marc Tchiboukdjian, Nicolas Gast, Denis Trystram, Jean-Louis Roch, Julien Bernard
• Keywords: Algorithms, Classical List Scheduling, ISAAC 2010, Processors, Single Centralized List