Loading...
Please wait, while we are loading the content...
Similar Documents
Optimization of Collective communication operations in MPICH (2005)
| Content Provider | CiteSeerX |
|---|---|
| Author | Thakur, Rajeev Rabenseifner, Rolf |
| Abstract | We describe our work on improving the performance of collective communication operations in MPICH for clusters connected by switched networks. For each collective operation, we use multiple algorithms depending on the message size, with the goal of minimizing latency for short messages and minimizing bandwidth use for long messages. Although we have implemented new algorithms for all MPI (Message Passing Interface) collective operations, because of limited space we describe only the algorithms for allgather, broadcast, all-to-all, reduce-scatter, reduce, and allreduce. Performance results on a Myrinet-connected Linux cluster and an IBM SP indicate that, in all cases, the new algorithms significantly outperform the old algorithms used in MPICH on the Myrinet cluster, and, in many cases, they outperform the algorithms used in IBM’s MPI on the SP. We also explore in further detail the optimization of two of the most commonly used collective operations, allreduce and reduce, particularly for long messages and nonpower-of-two numbers of processes. The optimized algorithms for these operations perform several times better than the native algorithms on a Myrinet cluster, IBM SP, and Cray T3E. Our results indicate that to achieve the best performance for a collective communication operation, one needs to use a number of different algorithms and select the right algorithm for a particular message size and number of processes. |
| File Format | |
| Volume Number | 19 |
| Journal | International Journal of High Performance Computing Applications |
| Language | English |
| Publisher Date | 2005-01-01 |
| Access Restriction | Open |
| Subject Keyword | Collective Communication Operation Collective Operation Long Message New Algorithm Myrinet Cluster Short Message Particular Message Size Message Size Many Case Bandwidth Use Different Algorithm Nonpower-of-two Number Old Algorithm Optimized Algorithm Ibm Mpi Several Time Ibm Sp Message Passing Interface Performance Result Limited Space Ibm Sp Indicate Multiple Algorithm Native Algorithm Myrinet-connected Linux Cluster Switched Network Cray T3e Right Algorithm |
| Content Type | Text |
| Resource Type | Article |
