[PATCH V4 1/6] mm: Introduce a general RCU get_user_pages_fast.

From: Steve Capper <redacted>
Date: Mon, 13 Oct 2014 12:44:28 +0100

Also, as a heads up for Sparc. I don't see any definition of
__get_user_pages_fast. Does this mean that a futex on THP tail page
can cause an infinite loop?

I have no idea, I didn't realize this was required to be implemented.