Re: [rfc 08/45] cpu alloc: x86 support

Christoph Lameter
2007-11-20T20:58:57Z

On Tue, 20 Nov 2007, Andi Kleen wrote:

>
> > This limitation shouldn't apply to the percpu area, since gs_base can be
> > pointed anywhere in the address space -- in effect we're always indirect.
>
> The initial reference copy of the percpu area has to be addressed by
> the linker.

Right that is important for the percpu references that can be folded by
the linker in order to avoid address calculations.

> Hmm, in theory since it is not actually used by itself I suppose you could
> move it into positive space.

But the positive space is reserved for a processes memory.