[openib-general] What context can CM be called from?

[Sean Hefty]

Libor Michalek wrote:

>>With this patch, changing the kmalloc in cm_alloc_msg() to use 
>>GFP_ATOMIC rather than GFP_KERNEL should allow the CM to be usable from 
>>interrupt context.  Of course, I haven't actually tested this...
>>
>>I have no objection to this change however.
> 
>   I could go either way on this issue myself. If the call can only be
> made from thread context I will use schedule_work() to execute the 
> request to send the dreq. However, I would imagine that other CM users
> would want to send requests in interrupt context...

My intention was that the CM should be able to match the calling 
conventions of underlying verbs/mad layer routines, except for the 
destroy_cm_id call that may block.  It should be easy enough to at 
least test whether the code works at interrupt with these changes, and 
if not, then call schedule_work until we can identify why not and see 
if other changes can be made to support it.

- Sean