Re: [PATCH] New user space serial port driver

Rogier Wolff
2000-11-30T10:18:31Z

Tigran Aivazian wrote:
> On Thu, 30 Nov 2000, Patrick van de Lageweg wrote:
> > +static struct tty_struct * ussp_table[USSP_MAX_PORTS] = { NULL, };
>
> this wastes at least 4 * USSP_MAX_PORTS bytes in the kernel image.
> Typically around 64 bytes but could be more. For more info see the recent
> silly flamewars on the list.

And I think the guys who were saying that the "documentation is more
important than those few bytes" were winning.

I am one of those guys. I think the documentation aspect is much more
important than those 64 bytes.

> The correct way is not to initialize the data
> to zero explicitly as BSS is cleared automatically on boot. It is also
> probably documented in the lkml FAQ at the bottom of this message.
>
> Also, it makes your code look consistent as, e.g. in cases below you do
> the right thing:
>
> > +static struct termios * ussp_termios[USSP_MAX_PORTS];
> > +static struct termios * ussp_termios_locked[USSP_MAX_PORTS];

this SHOULD mean that these are first initialized before use.

If you think they can be used before first being initialized by the
code, then that's a bug, and I'll look into it.

Roger.

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