Linux 4.15 rc4

So it looks like 4.15 is finally calming down, with rc4 being about
average size-wise for this time in the release process.

Of course, we not only have the holiday season coming up, we *also*
have some x86 entry and page table handling fixes pending. But that’s
not for today, and not for rc4. Let’s enjoy the short normal phase of
4.15 today.

The most noticeable thing to most normal users in rc4 is that we
should finally have cleaned up and fixed the suspend/resume handling.
That got first broken for some (unusual) kernel configurations due to
excessive debugging at a very inopportune time in early resume, and
when _that_ got fixed, we broke the 32-bit case. Not many developers
run 32-bit builds in real life any more, so that took a bit to even
notice.

Anyway, the good news is that as a result of that silly chaos, the
code is now a lot cleaner and more maintainable: none of the bugs here
were _complex_ per se, they were just a result of some really nasty
code and the fragility of resume bringup. It should all be good now.

Of course, that thing that may be noticeable to users is just a tiny
small detail, and not actually all that noticeable in the diffs or the
commit logs (below). As usual, the actual *bulk* of the changes tend
to be drivers, although this time there’s also a noticeable removal of
the cross-locking debug code that caused problems (not for normal
users, but for developers). So that adds to the diffstat, but doesn’t
affect most people. There’s still discussion about how to possibly
resurrect that code later.

Outside of the drivers and locking changes, there’s the usual noise
elsewhere: some filesystem fixes, some networking, some tooling. The
appended shortlog gives a taste of it all. It’s small enough that you
can scroll down and skim it for a sense of whats been going on.

I would like to say that I hope things will continue to calm down, but
I already know I have more stuff pending. That, together with the
holidays, makes me strongly suspect that this will be one of those
“we’ll do an rc8” releases, but we’ll see. I won’t actually make that
decision until we get to that point, and there’s little point in
worrying about it yet.

Go out and test. I think we’re in pretty good shape right now.

Linus