On Tue, Jun 15, 2021 at 5:50 PM Fabio Valentini <decathorpe(a)gmail.com> wrote:
On Tue, Jun 15, 2021 at 11:35 PM Neal Gompa <ngompa13(a)gmail.com> wrote:
>
> Hey all,
>
> Earlier this week, I was helping with processing features for openSUSE
> Leap 15.4[1] and I discovered that they're planning on introducing
> x86_64-v2 to openSUSE soon. The reference for this change was that
> RHEL 9 is going to use x86_64-v2[2]. Additionally, other distributions
> have been considering bumping up to v2 or v3[3][4].
>
> Some cursory examination of the new x86_64 sublevels seem to indicate
> that x86_64-v2 goes back to roughly 2007~2008, merely cutting off the
> first couple of generations of x86_64 CPUs from Intel and AMD. I
> personally don't have any computers that don't have support for
> x86_64-v2 anymore.
>
> Does anyone know if anyone is planning to propose this for Fedora
> anytime soon, either as an addon architecture (like what Arch is
> doing) or an upgrade of our x86_64 baseline like RHEL is doing?
>
> [1]:
https://en.opensuse.org/Feature_Planning_15.4
> [2]:
https://developers.redhat.com/blog/2021/01/05/building-red-hat-enterprise...
> [3]:
https://ml.mageia.org/l/arc/dev/2021-02/msg00583.html
> [4]:
https://www.phoronix.com/scan.php?page=news_item&px=Arch-Linux-x86-64...
Uhmmmm ... you mean something like this?
https://fedoraproject.org/wiki/Changes/x86-64_micro-architecture_update
Rejected by FESCo two years ago:
https://pagure.io/fesco/issue/2198
If I remember correctly, it was shot down pretty quickly on the devil
list, because Intel still produced CPUs that do not support AVX2.
Bumping the baseline to x86_64v2 would be different, since AVX is not
part of that (but only x86_64v3).
Yeah, I think that proposal was not workable because of AVX2. The
x86_64-v2 subarch adds SSSE3, SSE4.2, POPCNT, and CMPXCHG16B to the
current x86_64 baseline. All of these instructions were present in the
first Intel Macs launched in 2007, as I recall.
Different question: How is the runtime CPU feature detection /
dispatch support in glibc coming along? Shouldn't this "work" by now?
No idea, good question, though!
--
真実はいつも一つ!/ Always, there's only one truth!