Title :
On-demand Connection Management for OpenSHMEM and OpenSHMEM+MPI
Author :
Sourav Chakraborty;Hari Subramoni;Jonathan Perkins;Ammar A. Awan;Dhabaleswar K. Panda
Author_Institution :
Dept. of Comput. Sci. &
fDate :
5/1/2015 12:00:00 AM
Abstract :
Partitioned Global Address Space (PGAS) programming models like Open SHMEM and hybrid models like Open SHMEM+MPI can deliver high performance and improved programmability. However, current implementations of Open SHMEM assume a fully-connected process model which affects their performance and scalability. We address this critical issue by designing on-demand connection management support for Open SHMEM which significantly improves the startup performance and reduces the resource usage. We further enhance the Open SHMEM startup performance by utilizing non-blocking out-of-band communication APIs. We evaluate our designs using a set of micro benchmarks and applications and observe 30 times reduction in Open SHMEM initialization time and 8.3 times improvement in execution time of a Hello World application at 8,192 processes. In particular, when sufficient work can be overlapped, we show that use of non-blocking out-of-band communication APIs allow for a constant initialization cost of Open SHMEM jobs at different core counts. We also obtain up to 90% reduction in number of network endpoints and up to 35% improvement in application execution time with NAS Parallel Benchmarks.
Keywords :
"Electronics packaging","Runtime","Protocols","Servers","Computational modeling","Middleware","Memory management"
Conference_Titel :
Parallel and Distributed Processing Symposium Workshop (IPDPSW), 2015 IEEE International
DOI :
10.1109/IPDPSW.2015.104