Re: [PATCH] SMP initialization: detection and enumeration

[Almudena Garcia]

> You don't. Read about GDT and segments register, and segmentation in
> general. In the GDT you'd only store a pointer to the per-cpu data, and
> processors will load it.

> > Is there any way to avoid using an array for that?

> Yes, you'd just store the ID in the per-cpu data.

Thanks, I'll take notes about this

El jue., 30 jul. 2020 a las 23:35, Samuel Thibault (<samuel.thibault@gnu.org>) escribió:

Almudena Garcia, le jeu. 30 juil. 2020 23:30:55 +0200, a ecrit:
> > As Richard said, we just want to have different GDTs on the different
> > processors, so that we wan use the fs segment register to implement TLS
> > in the kernel and have per-cpu data cost essentially the same as global
> > data.
>
> Yes, but how can I store the relation APIC ID - Kernel ID in the GDT?

You don't. Read about GDT and segments register, and segmentation in
general. In the GDT you'd only store a pointer to the per-cpu data, and
processors will load it.

> Is there any way to avoid using an array for that?

Yes, you'd just store the ID in the per-cpu data.

Samuel