[openib-general] [PATCH 0/4] SA path record caching

[Hal Rosenstock]

On Tue, 2006-01-31 at 14:01, Sean Hefty wrote:
> Hal Rosenstock wrote:
> >>I see where a MultiPathRecord contains a path independence field.  But since it 
> >>only provides a single value for all other PathRecord fields for all SGID/DGID 
> >>pairs, it seems less flexible than PathRecords.
> > 
> > It depends on whether those components are wildcarded or not.
> 
> I was referring to the query response.

The query response is PathRecords not MultiPathRecords.
> 
> >>It's also missing LID information, 
> > 
> > Yes but is LID needed in the query ?
> 
> It's needed for connection establishment and QP modification.

but in the response, right ?

> >>and limits the number of DGIDs to 255.
> > 
> > Actually the number if lower as I think it is limited by the remaining
> > bits in the component mask.
> 
> For a fabric with 1000 or more nodes, the MultiPathRecord only returns paths to 
> 255 of the nodes, and then only if their path information matches.  (This is 
> part of why I'm confused about how to actually use a MultiPathRecord.)

You can wildcard the DGID (and DGIDCount).

>  From what I can tell, a MultiPathRecord does not eliminate the need to obtain 
> PathRecords, 

It's a better way to get PathRecords.

> and only provides a 2-bit path independence field that's always set 
> to 1.  It seems like I'm missing something here.

Aside from the independence field, there's 2 new fields" SGID/DGIDScope
to be used for explicit/node/system GID indication.

-- Hal