On Tue, Oct 20, 2015 at 3:00 PM, Jeff Squyres (jsquyres) <jsquy...@cisco.com > wrote:
> I don't think it gets up to 7 MCA params to guarantee a specific API path > is used to get to a specific network / port, but your overall point is fair. Jeff, it sounds to me you are responding to a different problem than the one I posed in my previous email. I am suggesting that a user wishes to NOT USE a specific port at all. In other words, I want to "obstruct" all of the API paths that might reach that port. However, they do want to use some other port of the same type - which means they cannot disable entire BTLs or MTLs. Unless I am missing something, they need to consider each possible API path through OMPI and pass a corresponding MCA param, such as btl_openib_if_exclude, to prevent that path from selecting the port in question. The problem is that the user may not know all the API paths that need to have a corresponding exclude. This is, in some ways, similar to the initial problem of how to disable all uses of mxm - it currently requires knowledge of all API paths that "might get you there". I am now seeing my concern turn in another direction, because a quick grep for "_exclude" in the OMPI 1.10.1 source turned up matches in only the openbl and usnic BLTs, and in oob_tcp. Is it really the case that an end user cannot instruct mxm, psm, psm2, portals4 or ofi not to use a specific IB port via mpirun? Does this really require resorting to library-specific env vars (which is even worse than the need for a long list of MCA params)? Just a reminder: I am *not* a user. If you choose to ignore me, it won't hurt my feelings. Even if you choose to pursue the concerns I've raised, in the end may not effect even a single end-user. I brought up these scenarios because I thought they bore some relation to the "disable all use of mxm" problem under discussion. Specifically they share the complications that arise from having multiple "API paths" to reach the same entity (which is either a library or a port). -Paul -- Paul H. Hargrove phhargr...@lbl.gov Computer Languages & Systems Software (CLaSS) Group Computer Science Department Tel: +1-510-495-2352 Lawrence Berkeley National Laboratory Fax: +1-510-486-6900
