On Thu, 2007-06-21 at 09:51, Michael S. Tsirkin wrote: > > Quoting Michael S. Tsirkin <[EMAIL PROTECTED]>: > > Subject: Re: Re: [PATCH] for-2.6.23 ib/umad: add partition support > > > > > Quoting Sean Hefty <[EMAIL PROTECTED]>: > > > Subject: RE: Re: [PATCH] for-2.6.23 ib/umad: add partition support > > > > > > >This assumes an open file desriptor per-pkey, so the proposed API > > > >extension umad_set_pkey would have to be changed to be per-port rather > > > >than per-mad. But I think this is a better API, too: most apps > > > >likely work within a single partition. > > > > > > I don't think this is true for apps that use the userspace MAD interface > > > (e.g. > > > opensm). > > > > SM (rather, SA) can just open file descriptor per pkey - it created them > > itself, > > and there's a small number of partitions. > > > > > Beyond that, this approach doesn't work for receiving MADs on different > > > PKeys. > > > > Yes, it does: we just filter out the MADs where pkey does not match. > > > > I think that most other apps (besides SA) should really treat > > each partition as a separate network. So getting MADs for a specific > > pkey, rather than all pkeys, makes total sense to me. > > Hal, could you pls comment on whether this approach will work for opensm?
I will answer at the "high" level rather than some of the details discussed in previous postings which we may get back to later. As far as SA is concerned, as all nodes are required to at least support the limited default partition, the SA uses the full default partition for communication. As to other current (and potential) management applications: PerfMgr will want PMA access on all ports on all nodes. It may also be constrained to a similar environment as SA (running on a node which supports the full default partition). If it is not constrained in such a manner, it needs to be on all partitions in the subnet or it will only be able to access a portion of the ports in the subnet. That actually might be a model some might ultimately want. Diagnostics may be happy with a single partition (or likely the set of partitions the end node they are running from reside on). Bottom line is that it can likely work with either model but there are tradeoffs underneath this "high" level which may not have been sufficiently explored/discussed as yet. I'm not sure I like having a different fd per pkey: It's a different model than currently being used and that would cause more changes to consumers (as opposed to the other approach) which aren't a clear win to me (and uses more fds). -- Hal _______________________________________________ general mailing list [email protected] http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
