Re: [PATCH] TTY: Fix loss of echoed characters (2nd follow-on PATCHattached)

[Andrew Morton]

On Mon, 08 Sep 2008 10:11:46 -0600
Joe Peterson <joe@xxxxxxxxxxx> 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.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/