[mvapich-discuss] one-sided passive communications

["María J. Martín"]

Hello,

We are using MVAPICH2.1-7 to run an asynchronous algorithm using one-sided passive communications on an Infiniband cluster. We observe that some unlocks take a long time to progress. If extra mpi calls are inserted, the times spent in some unlock calls decrease. It seems that the target of the remote operation should enter the MPI library to progress the unlock calls. However, we had understood from this article http://nowlab.cse.ohio-state.edu/publications/conf-papers/2008/santhana-ipdps08.pdf that this requirement was avoided through the use of RDMA data transfers. We have executed with the MV2_USE_RDMA_ONE_SIDED parameter set to 1 and to 0 but none difference was observed in the execution times. Any clarification about the behavior of passive one-sided communications would be welcome.

Thanks,

María

---------------------------------------------
María J. Martín
Computer Architecture Group
University of A Coruña
Spain


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.cse.ohio-state.edu/pipermail/mvapich-discuss/attachments/20121205/2472b74d/attachment.html