From: Andrew Morton <akpm@linux-foundation.org>
To: Joe Peterson <joe@skyrush.com>
Cc: alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] TTY: Fix loss of echoed characters (2nd follow-on PATCH attached)
Date: Mon, 8 Sep 2008 17:32:50 -0700 [thread overview]
Message-ID: <20080908173250.2452c5b8.akpm@linux-foundation.org> (raw)
In-Reply-To: <48C54EC2.4060901@skyrush.com>
On Mon, 08 Sep 2008 10:11:46 -0600
Joe Peterson <joe@skyrush.com> wrote:
> + spin_lock_irqsave(&tty->echo_lock, flags);
> lock_kernel();
Taking a spinlock outside lock_kernel() isn't good, and is quite unusual.
- It might be ab/ba deadlockable (I didn't check) (I trust you always
test with lockdep enabled?)
- will make Ingo unhappy when he applies his "make lock_kernel use
mutex_lock" patch (if it's still around).
- will probably give the -rt guys conniptions.
swapping the above two lines would presumably be an easy fix, but one
wonders whether we still need lock_kernel() in there once you've added
this lock.
next prev parent reply other threads:[~2008-09-09 0:33 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <200807252257.m6PMvieO003213@imap1.linux-foundation.org>
2008-08-20 15:36 ` [PATCH] TTY: Fix loss of echoed characters Joe Peterson
2008-08-26 12:41 ` Joe Peterson
2008-09-08 16:11 ` [PATCH] TTY: Fix loss of echoed characters (2nd follow-on PATCH attached) Joe Peterson
2008-09-09 0:32 ` Andrew Morton [this message]
2008-09-09 10:55 ` Alan Cox
2008-09-09 17:43 ` Andrew Morton
2008-09-09 20:42 ` Joe Peterson
2008-09-10 23:39 ` Andrew Morton
2008-09-11 12:53 ` Joe Peterson
2008-09-09 13:00 ` Joe Peterson
2008-09-09 13:12 ` Alan Cox
2008-09-09 13:15 ` Joe Peterson
2008-09-09 13:19 ` Alan Cox
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