ia64 removal (was: Re: lockref scalability on x86-64 vs cpu_relax)

[Ard Biesheuvel]

On Fri, 13 Jan 2023 at 01:31, Luck, Tony <tony.luck at intel.com> wrote:
>
> > Yeah, if it was ia64-only, it's a non-issue these days. It's dead and
> > in pure maintenance mode from a kernel perspective (if even that).
>
> There's not much "simultaneous" in the SMT on ia64. One thread in a
> spin loop will hog the core until the h/w switches to the other thread some
> number of cycles (hundreds, thousands? I really can remember). So I
> was pretty generous with dropping cpu_relax() into any kind of spin loop.
>
> Is it time yet for:
>
> $ git rm -r arch/ia64
>

Hi Tony,

Can I take that as an ack on [0]? The EFI subsystem has evolved
substantially over the years, and there is really no way to do any
IA64 testing beyond build testing, so from that perspective, dropping
it entirely would be welcomed.

Thanks,
Ard.



[0] https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/commit/?h=remove-ia64