shm: MPI_Win_create + MPI_Win_shared_query does not work about mpich HOT 3 OPEN

You are correct that in the current release MPI_Win_create does not make the memory accessible to other processes even when they are in the same shared domain. But it seems plausible with kernel modules such as CMA and XPMEM, we could expose the memory to each other. So stay tuned.

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I think it is a bug. It should return size 0 to tell you that the memory is not shared.

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Thank you for your quick reply!

I would like to linger on the question if MPI_Win_create will be able to create shared memory windows accessible with MPI_Win_shared_query? It currently does not look like it will be supported soon(?).

Would it be possible to highlight the fact that MPI_Win_create does not make memory available to MPI_Win_shared_query, and that these function call will always return size = 0, except when query the own window?

This could be done by adding a small sentence to the change log. This explicit mentioning of the fact would be very helpful!

Thanks.

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