Quoting from the Xv6 web page, "Adding multiprocessor support requires handling concurrency head on with locks and threads (instead of using special-case soluti

Quoting from the Xv6 web page, "Adding multiprocessor support requires handling concurrency head on with locks and threads (instead of using special-case solutions for uniprocessors such as enabling/disabling interrupts) and helps relevance." MINIX didn't have multiprocessor support until MINIX 3. Unlike MINIX 2, MINIX 3 is not designed as a teaching OS.