[ben509]

The CPU doesn't know what processes are, that's handled by the OS. So there still needs to be a fault.

[vlovich123]

You’re thinking about computer architecture as designed today. There’s no reason there isn’t a common data structure defined that the CPU can use to select a backup process, much how it uses page table data structures in main memory to resolve TLB misses.

[gpderetta]

X86 had the concept of harware assisted context switching. Yet another unsued feature dropped in 64bit mode.