Re: [PATCH] x86/mm: don't apply va_align to hugetlb mappings on AMD F15h

[Borislav Petkov]

On Fri, Aug 28, 2026 at 10:07:42AM -0700, Dave Hansen wrote:
> These AMD F15h CPUs are, what, 15 years old now? How bad of a
> performance hit *was* this issue? Is this optimization worth keeping around?

Oh, look, even back then I did perf measurements:

https://lore.kernel.org/all/1312550110-24160-2-git-send-email-bp@xxxxxxxxx/T/#m04c05a9a6f59b73d610b556f1efda8cd9e0487d1

8s penalty for kernel build workload on 3.0.

Do I care about Bulldozer?

Meh, I only have access to a laptop with that uarch and I've been using it
only to test kernels on it so, not really. Besides, we have Zens now which
are soo much better in every aspect so that Bulldozer looks more like a energy
waste than anything else.

But there are apparently folks which still use those and run new kernels on
them so we probably can't axe it off yet...

Looking on the bright side, Laurent can test patches ... :-P

HTH.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette