The 4.9 merge window closes

Linus has released 4.9-rc1 and closed themerge window for this release one day earlier than some might haveexpected. "My own favorite 'small detail under the hood' happens tobe Andy Lutomirski's new virtually mapped kernel stack allocations. Theymake it easier to find and recover from stack overflows, but the effortalso cleaned up some code, and added a kernel stack mapping cache to avoidany performance downsides." The virtually mapped kernel stack workwas covered here in June. There were14,308 non-merge changesets pulled for this release, meaning that 4.9 willbe, by far, the busiest development cycle ever.