[openib-general] multicast.c question

[Hal Rosenstock]

On Fri, 2007-01-12 at 14:26, Sean Hefty wrote:
> > There were hard coded values for pkey, qkey, and join state in
> > multicast.c.If so, where should these ultimately come from ?
> 
> A user specifies the values for the MCMemberRecord when they issue the join 
> request, so the user controls all values.  There is a call 
> (ib_sa_get_mcmember_rec) that can be used to lookup an existing record, or 
> obtain some default values for an MCMemberRecord if the user doesn't care what 
> they are.  I believe that the default values are the hard-coded values that 
> you're referring to.
> 
> The rdma_cm calls ib_sa_get_mcmember_rec() to lookup the broadcast group used by 
> ipoib.  It uses the returned MCMemberRecord as a template for creating new 
> groups.  The hard-coded values are only there for users that want to create a 
> group, and don't care anything about its values.
> 
> I hope this makes sense.

Makes sense with one minor comment:

The default pkey which is used for a default when the user doesn't care
might not be a valid pkey for that port.

-- Hal

> - Sean