The documents distributed by this server have been provided by the contributing authors as a means to ensure timely dissemination of scholarly and technical work on a noncommercial basis. Copyright and all rights therein are maintained by the authors or by other copyright holders, notwithstanding that they have offered their works here electronically. It is understood that all persons copying this information will adhere to the terms and constraints invoked by each author's copyright. These works may not be reposted without the explicit permission of the copyright holder.
Publications of SPCL
|T. Hoefler, T. Mehlan, F. Mietke, W. Rehm:|
|Adding Low-Cost Hardware Barrier Support to Small Commodity Clusters|
(In Proceedings of 19th International Conference on Architecture and Computing Systems - ARCS'06, presented in Frankfurt, Germany, pages 343-250, ISSN: 3-88579-175-7, Mar. 2006)
AbstractThe performance of the barrier operation can be crucial for many parallel codes. Especially distributed shared memory systems have to synchronize frequently to ensure the proper ordering of memory accesses. The barrier operation is often performed on top of point-to-point messages and the best algorithm scales with O(log2 P * L) in the LogP model. We propose a cheap hardware extension which is able to perform the task of synchronization in nearly constant time and implement a driver inside the Open MPI framework to speedup the MPI Barrier() call. We test our implementation with the parallel implementation of Abinit and the MPI overhead decreases by nearly 32%.