Dear RT folks!

I'm pleased to announce the v5.9.1-rt19 patch set.

Changes since v5.9.1-rt18:

  - Mike Galbraith reported a possible circular locking dependency with
    a seqcount. Backported a patch from upstream solving the issue.

  - David Runge reported a crash in the block layer.

  - The migrate-disable series by Peter Zijlstra has been update to v4.

  - Mike Galbraith a possible possible hang due to the new printk code.
    Dropped a patch from the printk code which was causing the problem
    as suggested by John Ogness.

  - The rtmutex clean up in v5.9-rc8-rt12 restructured the code path and
    removed the blk_schedule_flush_plug() invocation from the locking
    path. It turns out that it is still required and has been added
    back.

  - A small rtmutex related clean up:

    - Remove rt_mutex_lock_killable(), it has no users.

    - Use _mutex_lock_io_nested() for _mutex_lock_io() to avoid
      duplicated code.

Known issues
     - It has been pointed out that due to changes to the printk code the
       internal buffer representation changed. This is only an issue if tools
       like `crash' are used to extract the printk buffer from a kernel memory
       image.

The delta patch against v5.9.1-rt18 is appended below and can be found here:

     https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.9/incr/patch-5.9.1-rt18-rt19.patch.xz

You can get this release via the git tree at:

    git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git v5.9.1-rt19

The RT patch against v5.9.1 can be found here:

    https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.9/older/patch-5.9.1-rt19.patch.xz

The split quilt queue is available at:

    https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.9/older/patches-5.9.1-rt19.tar.xz



Sebastian

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>