Hi Viet, If MPICH_ASYNC_PROGRESS=1 is necessary for your application to terminate, i.e., you see a deadlock without this flag, the applications has a correctness/portability issue. This env variable should only have a possible impact to performance (better compute/communication overlap) but should not be necessary to avoid deadlock. You can compare this to the classical send-send deadlock (example 3.9 in the standard), where the application relies on buffering / eager communication, but all send suddenly block. The portable fix for the application is not to increase the eager-limit, but to fix the communication pattern. Best Joachim Am 07.01.21 um 13:08 schrieb viet via discuss:

Dear Hui Zhou,

Thank you for your response to this thread. Could you give me some references on this issue?

It seems that the below environment setting is necessary.

MPICH_ASYNC_PROGRESS=1

Thank you for anything you can provide. Best, Viet.

On Tue, Jan 5, 2021 at 5:59 AM Zhou, Hui <[email protected]> wrote:

...

You don’t need any special settings to use non-blocking MPI collectives in MPICH.

-- Hui Zhou

*From: *viet via discuss <[email protected]> *Date: *Friday, December 4, 2020 at 7:12 AM *To: *[email protected] <[email protected]> *Cc: *[email protected] <[email protected]> *Subject: *[mpich-discuss] Question about non-blocking MPI - 3

Hello everyone,

What is the environment setting for the use of non-blocking MPI-3 * collectives in mpich3.3?

In Intel MPI, the setting is as follows

$ export I_MPI_ASYNC_PROGRESS=1 $ export I_MPI_ASYNC_PROGRESS_PIN=<CPU list>

Is there an equivalent setting in mpich3.3? Thank you, Viet.

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