Which Linux Kernel timing or delay APIs to use for what?

I classify the waiting or timing API in the Linux kernel in two categories:
1. Which blocks the current thread of execution.
2. Something which has to be scheduled for later but we want the current thread to continue.
In most cases, the distinction between 1 and 2 is clear, but the techniques used to implement 2 can also be manipulated to behave like 1.

1. Blocking current thread of execution (Inline delays)
The API for 1. in the above case are: