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

[Sean Hefty]

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.

>>It's also missing LID information, 
> 
> Yes but is LID needed in the query ?

It's needed for connection establishment and QP modification.

>>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.)

 From what I can tell, a MultiPathRecord does not eliminate the need to obtain 
PathRecords, and only provides a 2-bit path independence field that's always set 
to 1.  It seems like I'm missing something here.

- Sean