RHEL9 Likely To Drop Older x86_64 CPUs, Fedora Can Better Prepare With "Enterprise Linux Next"

[cybertraveler]

I can't remember the name of it right now, but I know there's a compiler tech which compiles multiple versions of functions. Each version uses different CPU instructions, so you can get both the performance benefit and the compatibility. The down-side is the libs/executables will be larger. Also, I guess this would make inlining those affected functions difficult or impossible.

[Jabberwocky]

Guys,
By the time rhel9 becomes a thing, gcc will fully support "fat" binaries with multiple optimized versions of the same function and switching between them at runtime.
So I see no issue whatsoever to build whole distros with binaries that include all possible optimizations, from generic to avx512 and everything inbetween.

I also would like to know where development is taking place.

Last time I checked the idea was dropped:

https://softwareengineering.stackexchange.com/questions/274846/why-arent-fat-binaries-more-widely-used-for-cross-platform-applications

https://stackoverflow.com/questions/3741008/compiling-a-fat-executable-with-gcc

[pegasus]

Where can we follow the progress of this feature in gcc? Have patches been submitted for review?

I remember reading about it either here or on some mailing list but I'm unable to find it now. It's extremely un-googleable and I forgot how the project was called ...

[jelabarre59]

They do that' I'd have to throw out 80% of my hardware. And I'm not in the market to buy any more.

I guess I made the mistake all those years ago of not becoming Amish...

[skeevy420]

They do that' I'd have to throw out 80% of my hardware. And I'm not in the market to buy any more.

I guess I made the mistake all those years ago of not becoming Amish...

Me too. I intentionally buy old hardware. Like 5+ years old. It's cheaper. It's tried, true, and had enough time to get most of the bugs worked out. And in the case of x86_64, as long as the Ghz are above 3.3, it's 10 years or younger, and there are at least 8 threads available, it's good enough to play modern 1080p games if the GPU is new enough.

My exception is I'll wait a year on a GPU purchase...but, IMHO, a one year old GPU is damn near Legacy using GPU time frames. That's mainly due to a combination of being a Linux user and knowing about AMD's Fine Wine strategy.

[sfx2000]

this circus of chasing slighly less ancient hardware is such a waste of resources. one would think redhat has engineers who are able to defer binding of codegen options to host cpu to install time or run time

Not ancient HW - actually there's a fair amount of Intel current CPU's that do not support AVX/AVX2

This is fairly current - Intel Pentium Gold G5420 - this is "Coffee Lake", which is a Skylake derivative...

https://ark.intel.com/content/www/us...-3-80-ghz.html

And as I mentioned earlier - there's a lot of edge appliances that are on current Silvermont/Airmont boxes - Mostly focused on SDN deployments

So for a feature set - maybe Westmere... even though many actual legacy Westmere's have been pulled out of service.