Re: PAT and MTRRs

From: Arjan van de Ven
Date: Sun Oct 26 2008 - 20:34:49 EST


On Sun, 26 Oct 2008 17:21:41 -0700
"H. Peter Anvin" <hpa@xxxxxxxxx> wrote:

> Arjan van de Ven wrote:
> >
> > PAT can't make memory cachable that the MTRR's have as uncachable.
> > What PAT *can* do is, within an MTRR, do fine grained mapping...
> >
>
> Now, if it wasn't for the braindamage called ACPI and SMM, we could
> have cleared the MTRR settings and just used PAT...
>

yeah.. one thing we need to investigate is if we can set the default
"no mtrr coverage" value to cached
(and also.. to check we don't set that to uncached if the bios had it
set to cached..)


--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for ape savings,
visit http://www.lesswatts.org
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/