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From: Arnd Bergmann <arnd@arndb.de>
To: "Daniel K." <dk@uw.no>
Cc: linux-kernel@vger.kernel.org, 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>
Subject: Re: [PATCH 10/10] tty: implement BTM as mutex instead of BKL
Date: Sun, 16 May 2010 14:58:37 +0200	[thread overview]
Message-ID: <201005161458.37866.arnd@arndb.de> (raw)
In-Reply-To: <4BEF677A.2030003@uw.no>

On Sunday 16 May 2010 05:33:14 Daniel K. wrote:
> Arnd Bergmann wrote:
> > diff --git a/drivers/char/tty_mutex.c b/drivers/char/tty_mutex.c
> > new file mode 100644
> > index 0000000..f66dfdf
> > --- /dev/null
> > +++ b/drivers/char/tty_mutex.c
> > @@ -0,0 +1,47 @@
> > +/*
> > + * drivers/char/tty_lock.c
> > + */
> > +#include <linux/tty.h>
> > +#include <linux/module.h>
> > +#include <linux/kallsyms.h>
> > +#include <linux/semaphore.h>
> > +#include <linux/sched.h>
> > +
> > +/*
> > + * The 'big tty semaphore'
> 
> Referred to as Big TTY Mutex or BTM elsewhere.
> 
> 
> > + * This mutex is taken and released by tty_lock() and tty_unlock(),
> > + * replacing the older big kernel mutex.
> 
> big kernel lock, or BKL?
> 

Thanks for looking at this, this (and the bug you found in amiserial)
were caused by changing it a few times from one implementation to the next.

Fixed now and pushed out to git.

	Anrd

  reply	other threads:[~2010-05-16 12:59 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-05-15 20:59 [PATCH v3 00/10] BKL conversion in tty layer Arnd Bergmann
2010-05-15 20:59 ` [PATCH 01/10] tty: replace BKL with a new tty_lock Arnd Bergmann
2010-05-15 20:59 ` [PATCH 02/10] tty: never hold BTM while getting tty_mutex Arnd Bergmann
2010-05-15 20:59 ` [PATCH 03/10] tty: fix console_sem lock order Arnd Bergmann
2010-05-15 20:59 ` [PATCH 04/10] cdc-acm: remove dead code Arnd Bergmann
2010-05-15 20:59 ` [PATCH 05/10] tty: introduce wait_event_interruptible_tty Arnd Bergmann
2010-05-15 20:59 ` [PATCH 06/10] tty: annotate tty_write_lock Arnd Bergmann
2010-05-15 20:59 ` [PATCH 07/10] tty: reorder ldisc locking Arnd Bergmann
2010-05-15 20:59 ` [PATCH 08/10] tty: untangle locking of wait_until_sent Arnd Bergmann
2010-05-16  3:12   ` Daniel K.
2010-05-15 20:59 ` [PATCH 09/10] tty: remove tty_lock_nested Arnd Bergmann
2010-05-15 20:59 ` [PATCH 10/10] tty: implement BTM as mutex instead of BKL Arnd Bergmann
2010-05-16  3:33   ` Daniel K.
2010-05-16 12:58     ` Arnd Bergmann [this message]
2010-05-17 13:41 ` [PATCH v3 00/10] BKL conversion in tty layer Alan Cox
2010-05-17 15:30   ` Greg KH
2010-05-17 18:30     ` Arnd Bergmann
2010-05-18  4:27       ` Greg KH
2010-05-18 21:52         ` Arnd Bergmann
2010-05-19  1:50           ` Greg KH
2010-05-22 13:54             ` Arnd Bergmann
2010-05-17 18:49   ` Arnd Bergmann
2010-06-17 19:13   ` Tony Luck
2010-06-17 19:40     ` Arnd Bergmann
2010-06-17 20:15       ` Tony Luck
2010-06-17 21:48         ` Arnd Bergmann
2010-06-17 22:09           ` Frederic Weisbecker
2010-06-18 12:58             ` [PATCH] tty: avoid recursive BTM in pty_close Arnd Bergmann
2010-06-18 16:21               ` Alan Cox
2010-06-18 16:52                 ` Tony Luck
2010-06-18 18:35                   ` Arnd Bergmann
2010-06-18 20:25                     ` Tony Luck
2010-06-19 12:32                       ` Arnd Bergmann
2010-06-19 20:29                         ` [PATCH] serial: revert "Use block_til_ready helper" Arnd Bergmann
2010-06-19 21:57                           ` Alan Cox
2010-06-20 20:54                             ` Arnd Bergmann
2010-06-21 14:13                               ` Alan Cox
2010-06-21 20:57                                 ` Arnd Bergmann
2010-06-21 20:58                                   ` Arnd Bergmann
2010-06-21 17:11                           ` Tony Luck
2010-06-22 23:01                           ` Greg KH
2010-06-28 17:17                     ` [PATCH] tty: avoid recursive BTM in pty_close Tony Luck
2010-06-28 19:03                       ` Arnd Bergmann

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