On Friday, June 1, 2007 2:19:43 Andi Kleen wrote:
> On Fri, Jun 01, 2007 at 02:07:51PM -0700, Jesse Barnes wrote:
> > On Friday, June 1, 2007 2:14:17 Andi Kleen wrote:
> > > Jesse Barnes <[email protected]> writes:
> > > > (or we get proper PAT support, which I think would make this problem
> > > > go away as well).
> > >
> > > No it won't. If the basic MTRRs for memory are wrong just having PAT
> > > support in drivers (which already exist in a limited form already, just
> > > for UC only) won't change anything.
> >
> > No obviously just using PAT for drivers wouldn't help, I was thinking
> > more of having one PAT type be WB memory, and using it by default for
> > most PTEs
>
> Then the BIOS couldn't override it anymore in case it is needed somewhere.
> e.g. normally we just use normal 2MB direct mappings for the hole
> if there is memory beyond it and the hole doesn't need to be 2MB aligned.
> Just assuming UC for all reserved pages would be also pretty drastic
> and likely result in many 2MB pages being split and using a lot more
> TLB.
>
> > covering normal memory. If that's not possible, then it seems sensible
> > to
>
> And normally the MTRRs win, don't they (if I remember the table correctly)
> So if the MTRR says UC and PAT disagrees it might not actually help
I didn't check that part of the spec, that might be true. If so, then we
really need some sort of MTRR fix no matter what.
Jesse
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
