[ANNOUNCE] 3.18.7-rt1

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

Dear RT folks!

I'm pleased to announce the v3.18.7-rt1 patch set. It was running over
the weekend on my x86 box and was still alive this morning. However it
is still the first release for the v3.18 -RT series.
I haven't follow the mailing list or commented / applied any patches
from the list for -RT while being busy getting this release done (except
one patch I needed to have anyway). This is about to change. I will try to
go through my RT-inbox before doing the next release.

Changes since v3.14.25-rt22

- rebased to v3.18

- Added "Work Simple" from Daniel Wagner. I needed it for cgroup's RCU
  handling.
  
- "timers: do not raise softirq unconditionally" has been reverted. It
  has been added to optimize the FULL NOHZ case on CPUs which could avoid
  a softirq / timer wake up. Its been reverted because it breaks the
  switch to highres.

- added a few patches to get MQ-BLK and cgroups working.

Known issues:

      - bcache is disabled.

      - lazy preempt on x86_64 leads to a crash with some load.

      - CPU hotplug works in general. Steven's test script however
        deadlocks usually on the second invocation.

      - xor / raid_pq
        I had max latency jumping up to 67563us on one CPU while the next
        lower max was 58us. I tracked it down to module's init code of
        xor and raid_pq. Both disable preemption while measuring the
        measuring the performance of the individual implementation.

The RT patch against 3.18.7 can be found here:

   https://www.kernel.org/pub/linux/kernel/projects/rt/3.18/patch-3.18.7-rt1.patch.xz

The split quilt queue is available at:

   https://www.kernel.org/pub/linux/kernel/projects/rt/3.18/patches-3.18.7-rt1.tar.xz

Sebastian