RFC rtmutex: Simplify PI code

This is still a little buggy. I've been hitting a hang when running dbench 100 in a loop. But I also hit that hang with vanilla -rt.

But I'm sure this still has some things that need to be straighten out. Anyway, you can either apply the following patches or pull the code from the listed git repo.

This still needs to be worked out, but since I'm taking off for the rest of the year, I might as well show you where I ended up at.

The following patches are in:

git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-rt.git

branch: rt/tip/rt/devel

Lai Jiangshan (1):
rtmutex: Ensure only the top waiter or higher priority task can take the lock

Steven Rostedt (3):
rtmutex: Only save lock depth once in spin_slowlock
rtmutex: Try to take lock early in rt_spin_lock_slowlock()
rtmutex: Revert Optimize rt lock wakeup

----

 kernel/futex.c          |   22 +--
 kernel/rt.c             |   10 +-
 kernel/rtmutex-debug.c  |    1 -
 kernel/rtmutex.c        |  458 ++++++++++++++++++-----------------------------
 kernel/rtmutex_common.h |   18 +--
 5 files changed, 188 insertions(+), 321 deletions(-)