Linux 4.9 rc4

So it's once again a Saturday afternoon rather than Sunday, this timebecause I felt this rc was already big enough.Part of the size likely comes just from the fact that 4.9 is big andhas some fundamental changes: we have various fixups for drivers andfilesystems that triggered the whole "stack is now viirtually mapped,and physical addresses don't work" issue.But a larger part is simply that the first batch of networking fixescame in just after the rc3 release, which accounts for a large portionof this rc (about a third in bulk, slightly more in number of commits- spread out both over network drivers and core networking).So I'm not going to lie: this is not a small rc, and I'd have beenhappier if it was. But it's not unreasonably large for this (big)release either, so it's not like I'd start worrying.  I'm currentlystill assuming that we'll end up with the usual seven releasecandidates, assuming things start calming down. We'll see how thatgoes as we get closer to a release.Anyway, about half the changes are to drivers (networking being anotable part of it, but also media and gpu, with misc other noise).About a third is architecture updates (sparc and mips stand out, butthere's some x86 and parisc too, and some tiny arm updates). Theremainder is mostly core networking, with a smattering of otherchanges (filesystems, tests). And Arnd continues to get hisuninitialized variable warning fixes in, so that we hopefully canre-enable that warning for 4.9 final. Let's see.The appended shortlog isn't tiny, but you can kind of scan it for anoverview of the kinds of things that happened the past week.                       Linus