Re: x86_64 ten times slower than i386

From: Willy Tarreau
Date: Tue Nov 06 2007 - 15:02:23 EST


On Tue, Nov 06, 2007 at 11:50:13AM -0800, H. Peter Anvin wrote:
> Willy Tarreau wrote:
> >Just out of curiosity, what would be the problem if the MTRRs covered more
> >than the memory size ? For instance, instead of having 512 MB at 4G, why
> >not have 1G at 4G ?
>
> That's fine, *as long as* you don't have any I/O devices there,
> including things like UMA graphics devices or memory areas used by SMM.
> In theory, those should be marked reserved in e820. In practice...

OK, thanks Peter for the explanation.

Cheers,
Willy

-
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/