What are Linux Local timer interrupts?

Question

All is in the title. Any links to good documentations are welcome.

Answer 1

A less technical answer than Michael Burr's:

Some things need to be done every jiffy, doesn't matter on which CPU.
Other things need to be done every jiffy on each CPU. For example, checking if we need to switch to another process.

The local timer interrupt exists for the second type - whenever it's executed, we check them and do what's needed.