KS2010: Core kernel vision

So you do a check in the userspace code.

That sounds very much like how you have to re-call syscalls that were interruped by a signal. Is it a pain that you have to replace every call to close with a loop that breaks if errno != EINTR? Sure. But handling everything transparently is just way too complex, so some complexity is pushed onto the user. Sounds like inotify does the same. I see zero problem with that.