WHAT: Add a "connect" field to the openib BTL INI file to specify which connect pseudo-component(s) (CPCs) can be used for wireup of a given device.

WHY: 2 new CPCs are being written (by different parties); certain devices can only use certain CPCs.

WHERE: Mainly in btl_openib_ini.*, but probably also touch a few other btl_openib_* files.

WHEN: Sometime in the near future; no specific time set.

TIMEOUT: Friday, 2 Nov 2007

--------------------------------

In addition to the already-existing "oob" connect pseudo-component (CPC), two more are in the works:

- XRC: Pasha/Mellanox is working on a new XRC CPC for ConnectX HCAs.

- RDMA CM: Welcome to Jon Mason from Open Grid Computing (for Chelsio) who will be doing iWARP-related work in the udapl and/or openib BTLs. Either he or I will be implementing the RDMA CM-based CPC.

My proposal is that the "connect" field can be added to the INI file and take a comma-delimited list of values of acceptable CPCs for a given device. For example, the ConnectX HCA can take the following value:

    connect = xrc, rdma_cm, oob

Meaning:

- first, try the XRC CPC to try to make the connection
- if that fails, try the RDMA CM CPC
- if that fails, try the OOB CPC
- if that fails, fail the connection

iWARP-based NICs can use the following value:

    connect = rdma_cm

If no "connect" value is specified, then default value of "oob, rdma_cm" can be assumed (possibly someday changing to "rdma_cm, oob").

I mention this here on the devel list because disparate groups are working on different CPC's; coordination will be required to implement this arbitration mechanism.

Comments?

--
Jeff Squyres
Cisco Systems

Reply via email to