Copyright Notice:

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

S. Pellegrini, T. Hoefler, T. Fahringer:

 On the Effects of CPU Caches on MPI Point-to-Point Communications

(Vol , Nr. , In Proceedings of the 2012 IEEE International Conference on Cluster Computing, presented in Beijing, China, pages 495--503, IEEE Computer Society, ISSN: , ISBN: 978-0-7695-4807-4, Sep. 2012, )

Publisher Reference


Several researchers investigated the placing of communication calls in message-passing parallel codes. The current rule of thumb it to maximize communication/computation overlap with early binding. In this work, we demonstrate that this is not the only design constraint because CPU caches can have a significant impact on communications. We conduct an empirical study of the interaction between CPU caching and communications for several different communication scenarios. We use the gained insight to formulate a set of intuitive rules for communication call placement and show how our rules can be applied to practical codes. Our optimized codes show an improvement of up to 80% for a simple stencil code. Our work is a first step towards communication optimizations by moving communication calls. We expect that future communication-aware compilers will use our insights as a standard technique so move communication calls in order to optimize performance.


download article:
download slides:


  author={Simone Pellegrini and Torsten Hoefler and T. Fahringer},
  title={{On the Effects of CPU Caches on MPI Point-to-Point Communications}},
  booktitle={Proceedings of the 2012 IEEE International Conference on Cluster Computing},
  location={Beijing, China},
  publisher={IEEE Computer Society},