From: Theodore Tso <tytso@mit.edu>
To: Jon Smirl <jonsmirl@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>, lkml <linux-kernel@vger.kernel.org>
Subject: Re: tty's use of file_list_lock and file_move
Date: Mon, 10 Jul 2006 21:29:04 -0400 [thread overview]
Message-ID: <20060711012904.GD30332@thunk.org> (raw)
In-Reply-To: <9e4733910607101649m21579ae2p9372cced67283615@mail.gmail.com>
On Mon, Jul 10, 2006 at 07:49:31PM -0400, Jon Smirl wrote:
> How about the use of lock/unlock_kernel(). Is there some hidden global
> synchronization going on? Every time lock/unlock_kernel() is used
> there is a tty_struct available. My first thought would be to turn
> this into a per tty spinlock. Looking at where it is used it looks
> like it was added to protect all of the VFS calls. I see no obvious
> coordination with other ttys that isn't handled by other locks.
No, it was just a case of not being worth it to get rid of the BKL for
the tty subsystem, since opening and closing tty's isn't exactly a
common event. Switching it to use a per-tty spinlock makes sense if
we're going to rototill the code, but to be honest it's probably not
going to make a noticeable difference on any benchmark and most
workloads.
- Ted
next prev parent reply other threads:[~2006-07-11 1:29 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-10 15:10 tty's use of file_list_lock and file_move Jon Smirl
2006-07-10 17:33 ` Alan Cox
2006-07-10 17:27 ` Jon Smirl
2006-07-10 18:05 ` Alan Cox
2006-07-10 18:09 ` Jon Smirl
2006-07-10 23:18 ` Alan Cox
2006-07-10 22:35 ` Jon Smirl
2006-07-10 23:15 ` Alan Cox
2006-07-10 23:04 ` Jon Smirl
2006-07-10 23:49 ` Jon Smirl
2006-07-11 1:29 ` Theodore Tso [this message]
2006-07-11 2:16 ` Jon Smirl
2006-07-11 10:12 ` Alan Cox
2006-07-11 12:28 ` Jon Smirl
2006-07-11 13:15 ` Paulo Marques
2006-07-11 13:42 ` Jon Smirl
2006-07-11 3:33 ` Jon Smirl
2006-07-11 19:52 ` Russell King
2006-07-11 19:44 ` Russell King
2006-07-11 22:08 ` Jon Smirl
2006-07-11 22:37 ` Alan Cox
2006-07-11 23:28 ` Paul Fulghum
2006-07-12 0:00 ` Jon Smirl
2006-07-11 23:50 ` Jon Smirl
2006-07-12 3:55 ` Jon Smirl
2006-07-12 11:37 ` Alan Cox
2006-07-10 23:39 ` Theodore Tso
2006-07-11 0:25 ` Jon Smirl
2006-07-12 6:27 ` Pekka Enberg
2006-07-12 11:19 ` Alan Cox
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