[openib-general] hotplug support in mthca

[Michael S. Tsirkin]

Quoting r. Roland Dreier <rdreier at cisco.com>:
> Subject: Re: hotplug support in mthca
> 
>     Michael> How about fixing it by blocking remove_one in uverbs
>     Michael> until all contexts are closed and device refcount drops
>     Michael> to 0?
> 
> That seems kind of horrible, because there's no guarantee that all the
> contexts will ever be freed.

Hmm. Maybe that's an inherent limitation of user-space drivers?
Isn't this what happens for example if a sysfs file is open?

How about reporting an event to the application? Would that be sufficient?

> I think the real answer is to revoke all the contexts that userspace
> has.  But that doesn't seem trivial to do, which is why I haven't
> implemented it yet.

Right, this revoking doesn't sound like 2.6.18 material.
Isn't just blocking hotplug still better than letting bad things happen?

-- 
MST