This fixes a regression introduced by the RTSS'09
improvements.

Just calling unlink() on any task is not safe: it might
reside in a release heap. This was done in the case
that a new blocker increases a lock holder's priority.

To avoid crashing in this case, the FMLP code was changed
to be more careful when propagating an inherited priority.
The code now detects three different scenarios and uses
heap_decrease() to update the position of the lock holder's
heap node. This fixes a simple test case.

Used to adjust position of heap node after
the key of the node was decreased
(= made more important). Cannot be used if
key was increased (= made less important).

Stick get_release() to the rest of the bunch.

This removes the plugins created for RTSS'09 that
we don't want to track in mainline Linux.

Fix the operand constraints for the segment accessor functions,
{rd,wr}{fs,gs}*.  In particular, the 8-bit functions used "r"
constraints instead of "q" constraints.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

This fixes a bug that lead to task stacks being used s
simultaneously on two CPUs.

Line breaks, ammend comments, etc.

If schedule() was invoked twice in a retry, then the scheduled
task might have not been "picked" properly because it was
still scheduled.