[PATCH 2.6.20-rc5 0/4] futexes functionalities and improvements

[PATCH 2.6.20-rc5 0/4] futexes functionalities and improvements

[Pierre Peiffer]

Hi,

	Today, there are several functionalities or improvements about futexes included
in -rt kernel tree, which, I think, it make sense to have in mainline.

Among them, there are:
     * futex use prio list : allows RT-threads to be woken in priority order
instead of FIFO order.
     * futex_wait use hrtimer : allows the use of finer timer resolution.
     * futex_requeue_pi functionality : allows use of requeue optimization for
PI-mutexes/PI-futexes.
     * futex64 syscall : allows use of 64-bit futexes instead of 32-bit.

The following mails provide the corresponding patches.


I re-send this series for kernel 2.6.20-rc5 with this small modifications:

  - futex_use_prio_list patch stores now all non-real-time threads with the same
priority (MAX_RT_PRIO, which is a lower priority than real-time priorities),
causing them to be stored in FIFO order. RT-threads are still woken first in
priority order.
  - futex_requeue_pi: I've found (and corrected of course) a bug causing a
memory leak.

plist (patch 1/4) is still under discussion: I think it should be taken into
account, because it concerns a correctness issue with a very low cost as
drawback (I would even say "without noticeable cost" ;-) but that's my opinion
of course).
Anyway, I still can provide the same series without patch 1/4 if needed.

Comments and feedback are still welcome, as usual.

-- 
Pierre