[Click] about ToDevice

[Yihong Zhou]

Hi, Eddie:

I have a simple question:

How is "ToDevice" scheduled?  Let's say, it pulls packets from the queue
so that the click can control the timing of packet processing. ToDevice
is derived from AnyTaskDevice, and there is _Task private data member.
Is it scheduled periodically, or is it triggered by some other events?  

By the way, if we want to run click in the user level, do we need to
patch the linux kernel?

Thanks a lot.