I have read some books about os kernel recently. I knew that when an event (like clock ticks) happens, it will trigger an interruption then the kernel's specified routine response.
So my questions are: 1)When an interruption was triggered and its corresponding kernel routine was still running, then another interruption was triggered for some sort of reason. How will the kernel response? Will it mask the second interruption when it was handling the first interruption? Or the first interruption's corresponding routine was interrupted by the second one? If the second condition was true, how the kernel make sure the routines are "reentrance"?
2)Does the kernel multithreaded or multiprocess? I mean when things go like the first question, the kernel will use CPU's extra cores to handle interruptions? If it did, how can the kernel make sure everything works correctly just like running on a single-core CPU?