Subject: Re: Patch for two mbuf dma optimizations
To: Jason R Thorpe <thorpej@wasabisystems.com>
From: Ignatios Souvatzis <is@netbsd.org>
List: tech-kern
Date: 03/29/2003 23:08:01
Hi,
On Sat, Mar 29, 2003 at 01:32:28PM -0800, Jason R Thorpe wrote:
> On Sun, Mar 30, 2003 at 06:12:36AM +0900, itojun@iijlab.net wrote:
>
> > > /* description of external storage mapped into mbuf, valid if M_EXT set */
> > > struct m_ext {
> > > caddr_t ext_buf; /* start of buffer */
> >
> > is it a correct assumption that a page is 4K or smaller? 4096 should
> > be some constant from other headers (sys/ARCH/include/BLAH), i guess?
>
> Problem is that PAGE_SIZE and/or NBPG isn't a constant on some platforms,
> and this value needs to be a constant.
>
> I'm pretty sure we don't have any platforms where the page size presented
> to the OS is < 4K.
Isn't the VAX page size 1k?
-is