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

Christoph Lameter
2007-11-20T21:35:12Z

On Tue, 20 Nov 2007, H. Peter Anvin wrote:

> But you wouldn't actually *use* this address space. It's just for the linker
> to know what address to tag the references with; it gets relocated by gs_base
> down into proper kernel space. The linker can stash the initialized reference
> copy at any address (LMA) which can be different from what it will be used at
> (VMA); that is not an issue.

That is already provided by this patchset. The cpu area starts at absolute
0.

> To use %rip references, though, which are more efficient, you probably want to
> use offsets that are just below .text (at -2 GB); presumably
> -2 GB-[max size of percpu section]. Again, however, no CPU actually needs to
> have its data stashed in that particular location; it's just an offset.

Right. That is what we are discussion in another thread.