From owner-freebsd-hackers  Mon Nov  9 12:27:32 1998
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Date: Mon, 9 Nov 1998 12:18:07 -0800 (PST)
From: Julian Elischer <julian@whistle.com>
To: "Larry S. Lile" <lile@stdio.com>
cc: David Greenman <dg@root.com>, hackers@FreeBSD.ORG
Subject: Re: mbuf question 
In-Reply-To: <Pine.BSF.3.96.981109103125.26563D-100000@heathers.stdio.com>
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you can allocate a pool of buffers and attach them to the mbufs using th
eexternal pointer feature, and supply your own free and duplicate
functions.

I have done this under BSD since 1990
works like a charm..
(In my case the buffers were on the ethernet cards (2MB on each card))

julian

On Mon, 9 Nov 1998, Larry S. Lile wrote:

> 
> 
> On Mon, 9 Nov 1998, David Greenman wrote:
> 
> > >Are mbufs allocated below the 16M area?
> > >
> > >If they are, is it likely to change?
> > >
> > >Why?  Because I am trying to eliminate bcopy's and mallocs in my 
> > >token-ring driver to gain a little more performance.
> > 
> >    They're allocated throughout the machine's physical address space.
> 
> I was afraid of that, so I should just make new buffers and copy when
> I need DMA'able memory.  Otherwise I can just use the mbuf's directly.
> 
> Thanks!
> 
> Larry Lile
> lile@stdio.com
> 
> 
> 
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