[openib-general] Re: A Couple More CM Queries

[Hal Rosenstock]

On Fri, 2005-04-08 at 12:34, Sean Hefty wrote: 
> Hal Rosenstock wrote:
> > 1. cm_alloc_id does an idr_get_new_above starting at 1. Might this be
> > better saving the highest value and starting there so connection IDs are
> > less likely to repeat as soon ?
> 
> I _think_ this would result in the IDR tables growing to their maximum 
> size, which seems worse than repeating the IDs immediately after their 
> timewait expires.
> 
> > 2. Should ib_create_cm_id check return an error if cm_handler == NULL
> > just to make sure ?
> 
> Personally, I don't think it's worth this check for kernel clients, 
> unless we want to start checking for NULL parameters everywhere.

Incoming REQs currently use this capability anyhow.

> While on the CM, I did look at the issue of calling the API out of 
> order that you had pointed out before (which could result in accessing 
> a NULL port pointer).  I'm not convinced that a simple check for a NULL 
> port pointer covers all potential problems.  For example, I'm not sure 
> how well the codebase will handle the dynamic removal of a device while 
> users are attempting to access the device.

We may need to handle this at some point. Guess the changes may be larger
if/when we get there.

A couple more questions:

It looks like sending private data in REQ/REP/RTU, but incoming private data 
isn't handled on the receiving side. 

Also, in cm_process_send_error(), where the handler is called

cm_id_priv->id.cm_handler(&cm_id_priv->id, &cm_event);

might that callback request the CM ID destruction ? If so, some
code is missing to handle this.
  
Thanks.

-- Hal