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From: Jiri Slaby <jirislaby@gmail.com>
To: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: tty_driver->ttys association
Date: Wed, 11 Oct 2006 20:50:41 +0200	[thread overview]
Message-ID: <452D3D01.50001@gmail.com> (raw)

Hi,

I found this construction in the kernel:
static struct tty_driver *my_ttydriver;
static struct tty_struct *my_tty[PORTS + 1];
static struct termios *my_termios[PORTS + 1];
static struct termios *my_termios_locked[PORTS + 1];

...(alloc+set_op+...)
my_ttydriver->flags = TTY_DRIVER_REAL_RAW|TTY_DRIVER_DYNAMIC_DEV;
my_ttydriver->ttys = my_tty;
my_ttydriver->termios = my_termios;
my_ttydriver->termios_locked = my_termios_locked;
tty_register_driver(my_ttydriver);

The association is completely useless due to
if (p) {
     driver->ttys = (struct tty_struct **)p;
     driver->termios = (struct termios **)(p + driver->num);
     driver->termios_locked = (struct termios **)(p + driver->num * 2);
} else {
     driver->ttys = NULL;
     driver->termios = NULL;
     driver->termios_locked = NULL;
}

in tty_register_driver, isn't it? Can we save some memory?

thanks,
-- 
http://www.fi.muni.cz/~xslaby/            Jiri Slaby
faculty of informatics, masaryk university, brno, cz
e-mail: jirislaby gmail com, gpg pubkey fingerprint:
B674 9967 0407 CE62 ACC8  22A0 32CC 55C3 39D4 7A7E

                 reply	other threads:[~2006-10-11 18:50 UTC|newest]

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