"It would appear that Linus Torvalds has resolved to apply a
strict policy of accepting only bug fix changes to the kernel after
the merge window has closed. Torvalds has also stuck his oar into
the debate over the Android suspend block API and made the
situation even more complicated.
"For years, major changes for each new Linux kernel version have
been merged into the main development tree during the merge window,
which usually lasts about two weeks and concludes with the release
of the first pre-release version of the next kernel (2.6.x-rc1).
Thereafter, changes are theoretically restricted to patches which
fix existing bugs without giving rise to new ones. In practice, RC2
and RC3 have included the odd major change and some clean up work,
such as resolving compiler warnings, has found its way in at an
even later stage."