[ofa-general] Re: [PATCH V2 - libibverbs] Added reference count to completion event channels

[Dotan Barak]

Roland Dreier wrote:
> It seems that userspace is the only place that has a chance of making
> this work.  We just need to get the locking correct, and at first
> glance it looks possible to me.  If you don't see a way to do it then
> I'll work on it in the next day or so.
>   
I believe that we can avoid problems only if we will have a lock in the 
ibv_context that handles the completion channels.
Otherwise, we will always have a problem in the following scenario:

create_channel

thread 1                                         thread 2
---------                                        -----------

in create_cq:
is (channel)
                                                     destroy channel
get channel lock (seg fault)




If you think about a different solution i will be happy to ear about it.

If you think that adding a lock to the ibv_context is good enough i will 
send you a patch that implements this solution.


thanks
Dotan