>  * Instead of deprecating the set/getcheckinterval APIs, convert the
> arguments passed to these to the switch interval. The new APIs
> set/getswitchinteral are then not needed.

This is certainly not a good idea. The semantics are different, which is the reason why I created a separate API in the first place instead of recycling the old one.

Actually, there should be hardly any reason to want to change the interval with the new GIL implementation. It was required with the old GIL due to the fact that counting opcodes is a very poor way of estimating wall clock durations.

> Note that gettimeofday() et al. are rather slow APIs on most systems

In my measurements under Linux it seemed to be as fast as clock_gettime() actually. But I don't know about other systems. I didn't want to complicate the patch (with several different paths) more than seemed necessary.