ROMIO on Blue Gene /L

by Latham, Robert J.

The Blue Gene /L machine came out of IBM’s research division, and then became a product.  This unusual lineage resulted in its software stack using a bit more open source technology than usual.  For example, ROMIO provides the underlying MPI-IO implementation instead of IBM’s PE product.  Hao Yu published a paper at HPCA 2006 describing some of the improvements IBM made to ROMIO:

  • align file domains to block boundaries
  • use MPI collectives instead of point-to-point operations in ROMIO’s two-phase algorithm
  • selecting ROMIO’s two-phase aggregators such that they are spread out over Blue Gene I/O nodes

H. Yu, R. K. Sahoo, C. Howson, G. Almasi, J. G. Castanos, M. Gupta J. E. Moreira, J. J. Parker, T. E. Engelsiepen, R. Ross, R. Thakur, R. Latham, and W. D. Gropp, High Performance File I/O for the BlueGene/L Supercomputer, in Proc. of the 12th International Symposium on High-Performance Computer Architecture (HPCA-12), February 2006. DOI