Kernel user communication mechanism

[Konstantin Zertsekel]

> Was having a look at the netlink sockets. What will be the behaviour for
> sending an event which is blocking on the response from user-space the queue
> is full. How this case will be handled.
>
> Also fanotify makes use of fsnotify's notification mechanism to send events
> and get response from kernel. Is it possible to send event from user-space
> to kernel space in -case of fanotify.

Why is it interesting?
What is the story behind?
--- Kosta