BKL conversion in tty layer [LWN.net]

From:		Arnd Bergmann <arnd@arndb.de>
To:		linux-kernel@vger.kernel.org
Subject:		[PATCH v3 00/10] BKL conversion in tty layer
Date:		Sat, 15 May 2010 22:59:46 +0200
Cc:		Arnd Bergmann <arnd@arndb.de>, Alan Cox <alan@lxorguk.ukuu.org.uk>, Greg KH <gregkh@suse.de>, Frederic Weisbecker <fweisbec@gmail.com>, Thomas Gleixner <tglx@linutronix.de>, Andrew Morton <akpm@linux-foundation.org>, John Kacur <jkacur@redhat.com>, Al Viro <viro@zeniv.linux.org.uk>, Ingo Molnar <mingo@elte.hu>
Archive-link:		Article, Thread

This is the third attempt to get the BKL out of the
TTY code. This version goes much further than the
previous one, and eliminates most of the code I
had introduced there.
 
What remains of the series are changes to the existing
BKL usage in the TTY layer to avoid depending on
the autorelease-during-sleep or the recursive
behavior. The final patch simply adds the option
to replace the BKL with a plain mutex.

The series is available as a git tree in the bkl/tty branch of
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git
There is also a bkl/tty-history branch with a much
more detailed series that I used to get to this point.
Both series are bisectable.

Arnd Bergmann (10):
  tty: replace BKL with a new tty_lock
  tty: never hold BTM while getting tty_mutex
  tty: fix console_sem lock order
  cdc-acm: remove dead code
  tty: introduce wait_event_interruptible_tty
  tty: annotate tty_write_lock
  tty: reorder ldisc locking
  tty: untangle locking of wait_until_sent
  tty: remove tty_lock_nested
  tty: implement BTM as mutex instead of BKL

 drivers/char/Makefile          |    1 +
 drivers/char/amiserial.c       |   23 ++++--
 drivers/char/briq_panel.c      |    6 +-
 drivers/char/cyclades.c        |    2 +-
 drivers/char/istallion.c       |   12 ++-
 drivers/char/n_hdlc.c          |   16 ++--
 drivers/char/n_r3964.c         |   10 ++--
 drivers/char/pty.c             |   24 +++----
 drivers/char/selection.c       |   13 +++-
 drivers/char/serial167.c       |    4 +-
 drivers/char/stallion.c        |    2 +
 drivers/char/sx.c              |   12 ++--
 drivers/char/tty_io.c          |  138 ++++++++++++++++++++++-----------------
 drivers/char/tty_ldisc.c       |   43 +++++++++----
 drivers/char/tty_mutex.c       |   47 ++++++++++++++
 drivers/char/tty_port.c        |    2 +-
 drivers/char/vc_screen.c       |    4 +-
 drivers/char/vt_ioctl.c        |   12 ++--
 drivers/serial/68360serial.c   |    2 -
 drivers/serial/crisv10.c       |    6 +-
 drivers/serial/serial_core.c   |   39 ++++++++----
 drivers/usb/class/cdc-acm.c    |   12 +---
 drivers/video/console/vgacon.c |    2 -
 include/linux/tty.h            |   64 ++++++++++++++++++
 lib/Kconfig.debug              |   10 +++
 25 files changed, 338 insertions(+), 168 deletions(-)
 create mode 100644 drivers/char/tty_mutex.c