Re: [RFC 00/15] x86_64: Optimize percpu accesses

[H. Peter Anvin]

Arjan van de Ven wrote:
> On Wed, 09 Jul 2008 13:11:03 -0700
> Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
>
> > Ingo Molnar wrote:
> > > Note that the zero-based percpu problems are completely unrelated
> > > to stackprotector. I was able to hit them with a
> > > stackprotector-disabled gcc-4.2.3 environment.
> > The only reason we need to keep a zero-based pda is to support 
> > stack-protector.  If we drop drop it, we can drop the pda - and its 
> > special zero-based properties - entirely.
>
> what's wrong with zero based btw?

Two problems:

1. it means pda references are invalid if their offsets are ever more 
than CONFIG_PHYSICAL_BASE (which I do not think is likely, but still...)

2. some vague hints of a linker bug.

	-hpa
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