Subject: Re: Configuring memory parameters for large network-based services
To: Michael Graff <explorer@flame.org>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: tech-kern
Date: 03/22/1999 17:07:00
On Mon, 22 Mar 1999 12:48:21 -0800
Jason Thorpe <thorpej@nas.nasa.gov> wrote:
> > That is, what units is this in? I'm guessing 2048 (cluster size)
> > bytes.
>
> No, "clusters" in this sense is the historic "page cluster", i.e.
> VM page size (as opposed to hardware page size :-) In the NetBSD
> kernel, CLBYTES == PAGE_SIZE :-)
>
> Confusing enough yet? :-)
>
> So, on i386, 4k. On Alpha, 8k. On SPARC, 8k. Etc.
BTW, after reexamination of the code, NMBCLUSTERS does in fact mean
"number of mbuf clusters", not "number of VM pages in map". I have
clarified this in options(4), and fixed the ports which defined it
incorrectly (the PowerPC ports).
-- Jason R. Thorpe <thorpej@nas.nasa.gov>