[mvapich-discuss] Incorrect use of pSync/pWrk in OSU OpenSHMEM benchmarks

[Jithin Jose]

Thanks for the feedback, we will enhance the benchmarks in future release.


--
Jithin Jose


On Thu, Oct 24, 2013 at 5:55 PM, Sayan Ghosh <sayandeep52 at gmail.com> wrote:

> In some OSU OpenSHMEM benchmarks, there are back to back collective
> function calls using the same pSync/pWrk array, which violates the
> OpenSHMEM 1.0 spec :
>
> Page 58:
>
> The pWrk and pSync arrays on all PEs in the active set must not be in use
> from a prior
> call to a collective OpenSHMEM routine.
>
> Some OpenSHMEM implementations might fail when encountered with something
> like (an example from OSU OpenSHMEM benchmark):
>
>     shmem_double_min_to_all(&min_time, &latency, 1, 0, 0, numprocs, pWrk,
> pSyncRed);
>     shmem_double_max_to_all(&max_time, &latency, 1, 0, 0, numprocs, pWrk,
> pSyncRed);
>     shmem_double_sum_to_all(&avg_time, &latency, 1, 0, 0, numprocs, pWrk,
> pSyncRed);
>
>
> An easy fix would be to declare 2-D pSync/pWrk arrays/or multiple ones and
> use then alternatively:
>
> shmem_double_min_to_all(&min_time, &latency, 1, 0, 0, numprocs, pWrk[0],
> pSyncRed[0]);
> shmem_double_max_to_all(&max_time, &latency, 1, 0, 0, numprocs, pWrk[1],
> pSyncRed[1]);
> shmem_double_sum_to_all(&avg_time, &latency, 1, 0, 0, numprocs, pWrk[0],
> pSyncRed[0]);
>
> Thanks to Brian Barrett of Sandia Labs for pointing this out to me.
>
> --
> Thanks,
> Sayan
>
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>
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