Hello,

It seems that the silly compilation problem with hcoll_rte.c I had back in April with mpich 4.3.0 when using --with-hcoll=/opt/mellanox/hcoll configuration option is still present in 4.3.1, see:

https://lists.mpich.org/mailman/htdig/discuss/2025-April/006725.html

It seems that the following very simple patch I was told to try with 4.3.0 haven't been included in 4.3.1:

--- src/mpid/common/hcoll/hcoll_rte.c 2025-04-16 12:54:24.847337975 -0400

+++ src/mpid/common/hcoll/hcoll_rte.c 2025-04-16 12:55:05.428164974 -0400

@@ -55,7 +55,7 @@

/* FIXME: The hcoll library needs to be updated to return

* error codes. The progress function pointer right now

* expects that the function returns void. */

- ret = hcoll_do_progress(&made_progress);

+ ret = hcoll_do_progress(-1, &made_progress);

MPIR_Assert(ret == MPI_SUCCESS);

}

}

So it look like this code path is not compiled very often by mpich developers or it's QA process.

BTW applying the same patch fix the compilation problem, but:

What does it mean for us users ? Should we still use this option ? BTW hcoll is a very cool mechanism for improving collective operations efficiency. Is this option obsolete ? Was it replaced by something else ?

Thanks,

Martin Audet