Open MPI logo

Open MPI Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |  

This web mail archive is frozen.

This page is part of a frozen web archive of this mailing list.

You can still navigate around this archive, but know that no new mails have been added to it since July of 2016.

Click here to be taken to the new web archives of this list; it includes all the mails that are in this frozen archive plus all new mails that have been sent to the list since it was migrated to the new archives.

Subject: Re: [OMPI devel] IBCM error
From: Don Kerr (Don.Kerr_at_[hidden])
Date: 2008-07-16 11:07:30

Jeff Squyres wrote:
> On Jul 15, 2008, at 7:30 AM, Ralph Castain wrote:
>>> Minor clarification: we did not test RDMACM on RoadRunner.
>> Just for further clarification - I did, and it wasn't a particularly
>> good
>> experience. Encountered several problems, none of them overwhelming,
>> hence
>> my comments.
> Ah -- I didn't know this. What went wrong? We need to fix it if
> there are problems.
>>> RDMACM, on the other hand, is *necessary* for iWARP connections. We
>>> know it won't scale well because of ARP issues, to which the iWARP
>>> vendors are publishing their own solutions (pre-populating ARP caches,
>>> etc.). Even when built and installed, RDMACM will not be used by
>>> default for IB hardware (you have to specifically ask for it). Since
>>> it's necessary for iWARP, I think we need to build and install it by
>>> default. Most importantly: production IB users won't be disturbed.
>> If it is necessary for iWARP, then fine - so long as it is only used if
>> specifically requested.
>> However, I would also ask that we be able to -not- build it upon
>> request so
>> we can be certain a user doesn't attempt to use it by mistake ("gee,
>> that
>> looks interesting - let Mikey try it!"). Ditto for ibcm support.
> Pasha added configure switches for this about a week ago:
> --en|disable-openib-ibcm
> --en|disable-openib-rdmacm
I like these flags but I thought there was going to be a run time check
for cases where Open MPI is built on a system that has ibcm support but
is later run on a system without ibcm support.