
Linux Might Pursue x86_64 Micro-Architecture Feature Levels - rbanffy
https://www.phoronix.com/scan.php?page=news_item&px=Linux-x86-64-Feature-Levels
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dvaun
So upon reading the article my understanding of this is that GCC and LLVM can
possibly check CPU feature compatibility and dynamically link library versions
based on what's supported. Is that correct? If not could someone chime in?

I'm also curious about some comments I read on the article. As follows[0]:

>> I think AVX, or level B in that proposal, would be fine for the next
Redhat. AVX2 is a little too soon in my opinion. Yes for Intel AVX2 has been a
Haswell deal, but AMD processors only got AVX2 with Ryzen 3 years ago. Plenty
of Bulldozer family cpus are still being used. And even not all Intel users
have AVX2 even today. The original AVX goes a few years back for Intel, and a
lot of years back for AMD, and in my opinion is the sweet spot right now.
Level A seems old in 2020, those non AVX cpus are more than a decade old at
this point. A decade+ is a nice cutoff point, not too steep but not too old
either.

>> In any case, i am all for modernizing cpu-feature support. It is about
time.

> No. Most of the x86/amd64 just recently became available to third parties
> without having to license from Intel/AMD with the exception of the more
> recent vector instructions so letting the FOSS stack depend on AVX will
> vendor-lock x86 development out of the emerging Chinese chips. Besides,
> vector workloads that shouldn't be done by the GPU cores are rare anyhow so
> I just don't see the point from either a technical or political standpoint
> unless you happen to work for Intel/USG.

I'm not familiar with this space so I'm not sure if I'm understanding this
correctly. So when they say "...letting the FOSS stack depend on AVX will
vendor-lock x86 development out of the emerging Chinese chips" does that mean
that newer features are license-locked? And if that gives an advantage to
Intel/AMD over other semis based on the wide support for x86 then why would
this be pushed by RedHat instead of Intel or AMD?

[0]: [https://www.phoronix.com/forums/forum/phoronix/latest-
phoron...](https://www.phoronix.com/forums/forum/phoronix/latest-phoronix-
articles/1192755-linux-might-pursue-x86_64-micro-architecture-feature-
levels/page2)

