The 4.9 merge window closes Linus has released
4.9-rc1 and closed the
merge window for this release one day earlier than some might have
expected. "
My own favorite 'small detail under the hood' happens to
be Andy Lutomirski's new virtually mapped kernel stack allocations. They
make it easier to find and recover from stack overflows, but the effort
also cleaned up some code, and added a kernel stack mapping cache to avoid
any performance downsides." The virtually mapped kernel stack work
was
covered here in June. There were
14,308 non-merge changesets pulled for this release, meaning that 4.9 will
be, by far, the busiest development cycle ever.