Re: [PATCH] x86: Construct 32 bit boot time page tables in native format.

Pavel Machek
2008-01-25T22:11:00Z

Hi!

> > > >>I just looked at the ACPI suspend code, and it looks
> > > >>like it hacks its own identity map at runtime. Pavel,
> > > >>am I reading that code right?
> > > >
> > > >Yes, I think so, I believe we do it on both 32 and 64
> > > >bit now.
> > > >
> > >
> > > So the background to this... we need an identity map to
> > > trampoline at early boot, obviously, but we'd like it to
> > > not stick around more than necessary. We have
> > > zap_low_mappings() now but it's not really sufficient.
> > >
> > > Secondary SMP processors need these mappings during
> > > trampolining -- presumably including CPU hotplug -- and
> > > I'm suspecting it might simply make sense to use a
> > > separate set of page tables (with both the identity and
> > > the kernel map) for trampolining and just keep them
> > > around. That way they would be usable for ACPI as well.
> >
> > That would enable some cleanups, yes.
>
> Speaking of cleanups, the following one is applicable IMO.

ACK... and BTW ack for that deferred device removal series.

Pavel
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