[openib-general] Re: device add/remove in userspace

[Sean Hefty]

Roland Dreier wrote:
>     Sean> Is there a way for a userspace application to know if a
>     Sean> device has been added or removed?
> 
> We don't really handle this right now.  It could probably be made to
> work on top of hotplug/udev/hal/something but it seems tricky to me.

Any idea on how we currently want to handle this?  Can a device remove occur if 
a usermode app is using the device?

The kernel CMA will block until all connection identifiers associated with the 
removed device are freed.  I export the device removal up to userspace through 
the uCMA, but that leaves the kernel blocked until the userspace application 
cleans up.  Doing something more intelligent requires a lot more effort.

- Sean