Thank you folks. I'd have loved to get an older libfabric, but an oldish kernel version at MN4 prevented me from compiling a more recent one. I'll give your suggestions a try once I get the chance to spend some more time on this.   Toni El 16/6/21 a las 21:47, Zhou, Hui escribió:

Yeah, as Wesley suggested, it will shed more light if you try set the environment variable MPIR_CVAR_CH4_OFI_CAPABILITY_SETS_DEBUG and get some diagnostics. We haven’t tested against such old libfabric for a while so some discrepancy in the capability set may have crept in.

-- Hui Zhou

*From: *Bland, Wesley via discuss <[email protected]> *Date: *Wednesday, June 16, 2021 at 8:47 AM *To: *Antonio J. Peña <[email protected]> *Cc: *Bland, Wesley <[email protected]>, MPICH Discuss <[email protected]> *Subject: *Re: [mpich-discuss] libfabric+psm2 performance

If you set the environment variable MPIR_CVAR_CH4_OFI_CAPABILITY_SETS_DEBUG, it will print out the capability set (and provider) that MPICH is using so you can confirm.

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