I'll quote Andi Kleen's post (that I linked above) since I think it's abundantly clear:
Newer Intel CPUs support a new class of machine checks called recoverable action optional. Action Optional means that the CPU detected some form of corruption in the background and tells the OS about using a machine check exception. The OS can then take appropiate action, like killing the process with the corrupted data or logging the event properly to disk.
Read that again: Background scrubbing gives a machine check. The machine check is action optional and it can do just as you suggest. It's still a machine check.
Copyright © 2018, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds