Date: Mon, 19 Jul 1999 13:53:29 -0400 (EDT) From: "Brian F. Feldman" <green@FreeBSD.org> To: Jason <jes@hal-pc.org> Cc: freebsd-current@FreeBSD.org Subject: Re: Question about MTRR boot message Message-ID: <Pine.BSF.4.10.9907191351470.40596-100000@janus.syracuse.net> In-Reply-To: <002b01bed20b$5547e1c0$0500a8c0@local.nullifier.dyn.ml.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 19 Jul 1999, Jason wrote:
> Before you go any further worrying about this "just in case", there is
> nothing for you to worry about. Part of what the MTRR "stuff" does is it
> stops the L2 cache from cacheing that range of memory. This is typicaly used
> for video cards, as you have been told, because well, you really never read
> back from the video card's memory frame buffer, and if you did, for some
> strange reason, it would only result in a cache miss and would then have to
> be fetched from main memory. Since your L2 cache isn't wasting space on this
> area of memory, it can cache something more usefull, and thus give you a
> speed *increase*.
>
I wrote the K6-2 MTRR support, but I really don't know how to use it.
You see, my X server reports:
(--) SVGA: PCI: NVidia Riva TNT rev 4, Memory @ 0xef000000, 0xcc000000
But which do I make uncacheable?
>
> Thus, MTRR is GOOD.
>
> - Jason
>
Brian Fundakowski Feldman _ __ ___ ____ ___ ___ ___
green@FreeBSD.org _ __ ___ | _ ) __| \
FreeBSD: The Power to Serve! _ __ | _ \._ \ |) |
http://www.FreeBSD.org/ _ |___/___/___/
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.4.10.9907191351470.40596-100000>