Re: [RFC] use realmode code to reserve end-of-conventional-memory to 1MB

Ingo Molnar
2008-03-04T16:23:48Z

* Mark McLoughlin <markmc@redhat.com> wrote:

> > i'm wondering, what triggered this bug, and why didnt we have these
> > problems in the past?
>
> That's been bothering me too, but hadn't come up with anything until I
> just now looked again.
>
> I'm pretty certain that dmi_scan_machine() wasn't using a fixmap
> before (in 2.6.24) since I had to fix a broken xen dom0 patch to
> handle this new situation.

ah, ok, indeed Jeremy's gut feeling about early_ioremap() was right - we
didnt use fixmaps for early_ioremap() [ ex. bt_ioremap() ] in .24. We
try to slowly get rid of the linearity assumptions from arch/x86, this
was one of the steps.

Ingo