Problem exchanging margo addresses in SLURM PMI2

[adammoody]

I was curious whether you have seen this.

LLNL/UnifyFS#626 (comment)

I think that SLURM PMI2 may be internally using the ; character to split a string into a list of key/value pairs. Margo address use the ; character, so then a put like:

PMI2_KVS_Put("unifyfs.margo-svr", "ofi+tcp;ofi_rxm://123.123.123.123:55555")

to exchange margo addresses via SLURM PMI2 produces an error message like:

slurmstepd: error: mpi/pmi2: no value for key ;ofi_rxm://123.123.123.123:55555; in req

I worked around this with a hack to replace ; with ! before submitting the key/values to PMI2, and then converting back after pulling the value back out of PMI2.

If that's what is going on, it's more a SLURM issue, but I just bring it up since other margo users might hit it.

[mdorier]

You should be able to replace the whole ofi+tcp;ofi_rxm part with just tcp and Mercury is going to figure out the rest.