Re: [PATCH] modules: Use a better scheme for refcounting

Rusty Russell
2008-05-18T14:32:03Z

On Saturday 17 May 2008 17:36:21 Eric Dumazet wrote:
> Christoph Lameter made good work last year and apparently the path is to :
>
> 1) Put pda at the begining of percpu section.

Well, we killed the pda on i386: it's basically a limited arch-specific percpu
section. Unfortunately, ISTR that doing so kills -fstack-protector on x86-64
(gcc was explicitly patched to support the kernel doing this, but it nailed
us to a fixed offset off %fs). But the PDA is a redundant idea which should
be removed.

> 2) Relocate percpu variables to begin at zero
> 3) Use %gs (or %fs) register to address pda AND percpu section.

Thanks for the prod Eric. ISTR acking those patches; Christoph, what happened
to them?

Cheers,
Rusty.