Re: [PATCH] mvme147: use correct order of ram pages

Geert Uytterhoeven
2014-05-28T07:51:39Z

Hi Amos,

On Wed, May 28, 2014 at 6:07 AM, Amos Kong <akong@redhat.com> wrote:
> 16K is 2^2 * PAGE_SIZE, so the page order should be 2, not 3.
>
> This patch uses get_order() to get correct order, and fixes
> one typo in comment.

Thanks for your patch!

> Signed-off-by: Amos Kong <akong@redhat.com>
> ---
> This patch wasn't built. Geert, can you help to test it?
> I don't know if it needs a head file by using get_order().

It builds fine. The get_order() is nicely expanded to "2" in the assembler
output.

Now, I'd like to get some feedback from the MVME hackers first.
Perhaps the comment was wrong?

> -/* We have 16834 bytes of RAM for the init block and buffers. This places
> +/* We have 16384 bytes of RAM for the init block and buffers. This places
> * an upper limit on the number of buffers we can use. NetBSD uses 8 Rx
> * buffers and 2 Tx buffers.
> */
> +#define M147LANCE_RAM_SIZE 16384 /* 16K */
> #define LANCE_LOG_TX_BUFFERS 1
> #define LANCE_LOG_RX_BUFFERS 3

BTW,I also find it fishy why the driver uses only 1+3 buffers, since more
RAM is available.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds