[openib-general] [PATCH] expand local SA cache to include all path records from source

[Hal Rosenstock]

On Thu, 2006-04-20 at 18:28, Sean Hefty wrote:
> Modify the local SA cache to store all path records from the local
> SGID to all destinations.  The current implementation retrieved only
> a single path to each destination.
> 
> Add API calls that can be used to walk the list of known paths to a
> given DGID.
> 
> This allows a user to select an alternate path for a connection, and
> provide their own filtering on available paths.

As the end node cannot know the policies the SM used for routing, etc.,
path records are insufficient in terms of some of the interesting
characteristics for filtering like path independence (as fault
independent as possible). 

There's also a 1.2 erratum which enhances SA MultiPathRecord to support
scoping of S/DGIDs. It supports explicit, same node, same system with
and without high availability (separate HCAs). That could also be used
when supported by the SA.

So rather than all available paths to the DGID, it could be fault
independent ones by making a different request underneath.

The API looks fine to me. One thing to note is to keep an eye on the
lookups done on the local database and possibly optimizing them if
needed.

-- Hal

> Signed-off-by: Sean Hefty <sean.hefty at intel.com>