[openib-general] RE: [RFC] [PATCH 1/2] multicast support for multiple users

[Sean Hefty]

>There's also code in opensm/osm_sa_mcmember_record.c that you can
>peruse.

Thanks - that's helpful.

>> The code uses a promotion/demotion mechanism based on a reference count of
>> membership types.  The restriction is that only a single request per group is
>> active at a time.
>
>Meaning only one of the membership types is active outside the node ? If
>so, that seems right as long as the order of precedence is correct.

Only one MAD request per group is active at any time, regardless if the MAD is
for a join or leave.

>How does the change in precedence occur ? Is it a leave followed by the
>new join or the new join followed by the old leave ?

Either through a join or leave, depending on if the group is being promoted or
demoted.  For example, if a send-only group is joined by a full member, a new
join is issued with an updated join state.  If the full member later leaves, a
leave request is issued for that join state.

- Sean