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

From: Thomas Schlichter
Date: Tue Oct 20 2009 - 16:35:30 EST


Ingo Molnar wrote:
> * Thomas Schlichter <thomas.schlichter@xxxxxx> wrote:
> > > or Perhaps just try to add mtrr only for the pci mmap case like the
> > > 4th patch in this series..
> >
> > I'd prefer this! ;-)
>
> Hm, we could perhaps do that - but i think we should only do that on
> systems that have PAT disabled.

The patch I sent should do exactly that.

> Which brings up the question of how to properly QA such a narrow segment
> of the market. Maybe disabling CONFIG_X86_PAT should enable that logic
> too.

When CONFIG_X86_PAT is disabled, pat_enabled is 0, and thus my new code should
be active. Or do I miss something?

What do you think about the latest version of my patch series I just sent?

Kind regards,
Thomas
--
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/