There is environment variable MPIR_CVAR_CH4_XPMEM_ENABLE which is set to 1 by default. And there is MPIR_CVAR_CH4_IPC_XPMEM_P2P_THRESHOLD which is set to 16384 by default.

This Message Is From an External Sender

This message came from outside your organization.

Hello,

Thanks. Besides compiling MPICH with xpmem support, are there any particular configuration options or environment variables needed for this to happen?

Kind regards,
Pascal Boeschoten

On Mon, 29 Apr 2024 at 15:54, Zhou, Hui <zhouh@anl.gov> wrote:

Yes, intra-node ipc including non-contig datatypes is supported via xpmem.

--

Hui Zhou

From: Pascal Boeschoten via discuss <discuss@mpich.org>
Sent: Monday, April 29, 2024 2:37 AM
To: discuss@mpich.org <discuss@mpich.org>
Cc: Pascal Boeschoten <pascal.boeschoten@hapteon.com>
Subject: [mpich-discuss] Zero-copy non-contiguous types

Hello, Does MPICH support zero-copy intra-node communication for non-contiguous datatypes? Thanks, Pascal Boeschoten ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍

ZjQcmQRYFpfptBannerStart

This Message Is From an External Sender

This message came from outside your organization.

ZjQcmQRYFpfptBannerEnd

Hello,

Does MPICH support zero-copy intra-node communication for non-contiguous datatypes?

Thanks,
Pascal Boeschoten