Re: [RFC Patch] use MTRR for write combining if PAT is not available

From: Thomas Schlichter
Date: Sun Oct 11 2009 - 06:03:45 EST


Arjan van de Ven wrote:
> Thomas Schlichter wrote:
> > So, convincing Ubuntu to enable PAT would be a workaround, but I think
> > the problem would still exist and should be fixed.
>
> I think it's time to get rid of CONFIG_PAT at all.. and just have it be
> there. Making 10+ year old CPU features that are essential functionality a
> config option... ... not a good idea to be honest.

I do completely agree with you in this point.

But should the current behavior of not using MTRR for write combining when PAT
is disabled (for whatever reason) stay? I think it is more consistent to do
whatever is necessary to enable write combining when we are asked to.

Kind regards,
Thomas
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