Linux Might Pursue x86_64 Micro-Architecture Feature Levels

[NotMine999]

Sounds to me like a way for Red Hat, now IBM, to monetize different market sectors of processors.

And that sounds a lot like what IBM did when they brought out their mainframes in the 1960s; model types stratified processor power and computer features.

That old saying really is true: "What is old is new again."

[NotMine999]

Requiring AVX2 would be to high for Red Hat. At a big automotive company I worked, most dev machines had 2nd and 3rd gen i5/i7 CPUs(old Dell Machines that are bought once and used forever) - that's tens of thousands of machines that wouldn't be compatible, at least at that company.

I know the situation you describe relative to the article. It's called "the pebble in a still pond" effect. A simple change, like upgrading software, that forces other changes.

When those ripples start to cause hardware changes to occur, then Corporate IT starts to really worry about management support, and management starts to consider other vendors along with staffing changes in IT.

From the vendor's side of the table:
Some vendor sales teams will agonize over total honesty and fully disclosing the change impacts they perceive at the risk of scuttling the deal. Other vendor sales teams say only enough to get the customer to ink the contract and handover the check while risking ill will and legal fallout later. Most sales teams fall between these two endpoints.

[ms178]

not everyone care or have enough money to upgrade every years

Every company should care about IT security. If they don't, it is a big liability for them. Sooner or later this will cause them trouble.

[andrebrait]

Tbh, given how AVX is a complicated thing even for modern CPUs (like requiring a clock speed reduction in order to work or increasing power consumption considerably) I think stopping at SSSE3/SSE4.1/SSE4.2 would be good enough (talking about vectored math instructions exclusively).

[Niarbeht]

I could also see this working its way into a distro like Arch, where either the system detects the CPU level and downloads only appropriate binaries, or the user is asked if this is a portable installation that will be moving around a lot and thus the base-level should be used, or if some specific other level should be used.

[Sonadow]

If that is the case I'm going to be permanently stuck at Level A.

Most Chinese OEMs are focusing on laptops and mini PCs with Atom and Celeron processors like the N4100, J4155 and N5405u that only support the most minimal of x64 instructions. And I have huge interest in these machines because of their ridiculously low cost and great value for money (Chinese OEMs usually pair such laptops with FullHD or QHD displays, replaceable SSDs and backlit keyboards).

[pal666]

Let's hope that this won't take another decade to see the light in distributions. I'd very much like to see a Level C fully optimized distribution build.

i think subj is only concerned with libraries, leaving /usr/bin on level a

[pal666]

Sounds to me like a way for Red Hat, now IBM, to monetize different market sectors of processors.

for everyone else it sounds like a way to build faster distros

[pal666]

from linked mail

I'm fairly confident that a version of these changes will make it into glibc 2.33, and I hope to backport them into Fedora 33, Fedora 32, and Red Hat Enterprise Linux 8.4

isn't it nice when your distro package maintainer is upstream project maintainer?

[jrch2k8]

Sounds to me like a way for Red Hat, now IBM, to monetize different market sectors of processors.

And that sounds a lot like what IBM did when they brought out their mainframes in the 1960s; model types stratified processor power and computer features.

That old saying really is true: "What is old is new again."

just leaving this here Function multi-versioning. see more https://lwn.net/Articles/691932/

is not as fun as conspiracy theories but well.

Now as chaplain also added this is GCC specific(not sure about clang support atm) so some libraries will have to be shipped with variants instead, libMylib_A/b/c/d.so.0.0.0 and glibc or its respective runtine should load the right one