flux-core icon indicating copy to clipboard operation
flux-core copied to clipboard

Published 20 hours ago • verified publisher icon flux-framework

PMI2 interface support?

Open j0hnL opened this issue 2 years ago • 1 comments

I understand PMI2 interface is "mostly" supported, is there any documentation on what is supported from the standard?

j0hnL avatar Mar 04 '22 17:03 j0hnL

There is not really any documentation. What we have is the minimum needed to bootstrap mvapich in a PMI-2 only configuration, and a couple of functions needed by Cray MPI (but I think not all). It's a bit hacky and implemented on top of PMI-1. More specifically:

  • some functions are stubbed out and return an error
  • many pre-set PMI2 keys are missing from the kvs
  • does not support multiple outstanding requests
  • does not support access from multiple threads/procs per rank

The source is pretty short so might be easier to just scan through:

https://github.com/flux-framework/flux-core/blob/master/src/common/libpmi/pmi2.c

garlick avatar Mar 04 '22 18:03 garlick