[mvapich-discuss] RMA on MVAPICH2

[Dhabaleswar Panda]

There was an issue with on-demand connection management and RMA functions
in mvapich2 1.2p1. The default value of MV2_ON_DEMAND_THRESHOLD=64. If you
want to run rma functions on larger systems (say 128), you can specify
MV2_ON_DEMAND_THRESHOLD=128. This issue has been fixed long back in 1.2
branch version. Since mvapich2 1.4 has been released for quite some time,
I will strongly encourage you to switch to this latest (1.4) version. In
fact, please use the latest branch version of 1.4 from the following URL:

 http://mvapich.cse.ohio-state.edu/nightly/mvapich2/branches/1.4

This has some additional fixes compared to the 1.4 release version.

Thanks,

DK

On Tue, 8 Dec 2009, Satoshi Isono wrote:

> Dear members,
>
> I have a question about RMA (Remote Memory Access) function when using MVAPICH2. My MVAPICH2 is 1.2p1 version.
>
> In case of specifying 65 processes, I tried to use RMA functions which are MPI_Win_create and MPI_Win_fence, but this code did not work. When I specify under 64 processes, it works without problem.
>
> Then I did test with option MV2_USE_RDMA_ONE_SIDED=0, it works with 65 processes.
>
> I understand that MVAPICH2 sets optimal RMA function on default. Does above result show bug in MVAPICH2? With other MPIs like OpenMPI or HP-MPI, does it occur same result?
>
> I would like to know MVAPICH2 specification on RMA function.
>
> Best regards,
> Satoshi Isono
>
>
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