Re: [RFC][PATCH 0/5] preempt_count rework

H. Peter Anvin
2013-08-14T16:58:58Z

On 08/14/2013 09:52 AM, Peter Zijlstra wrote:
>
> Oh curses, this is because lea can't do segment offsets? So there's no
> sane way to get addresses of per-cpu variables.
>
> Because ideally we'd have something like:
>
> lea %gs:__percpu_runqueues,%rax
>
> So in this case it makes sense to also store the actual pointer; how
> unfortunate.
>

Correct; the segment offset is not part of the effective address, even
in 64-bit mode.

-hpa