Linus Torvalds' comments came from this article: https://is.gd/6zpZRL
His comments came in a mailing list (via Phoronix) discussing an article suggesting AVX-512 might not be part of Intel's upcoming Alder Lake architecture. If that comes to pass, it will be just fine by Torvalds.
"I hope AVX512 dies a painful death, and that Intel starts fixing real problems instead of trying to create magic instructions to then create benchmarks that they can look good on. I hope Intel gets back to basics: gets their process working again, and concentrate more on regular code that isn't HPC or some other pointless special case," Torvalds said.
Intel introduced AVX-512 in 2013, initially as part of its Xeon Phi x200 and Skylake-X processor lines. It has also found its way into more current CPU architectures, including Ice Lake.
The instruction set is designed to bolster performance in various types of workloads, such as scientific simulations, financial analytics, artificial intelligence, data compression, and other tasks that can benefit from more robust floating point operations.
Nevertheless, Torvalds views AVX-512 as an example of "special-case garbage," noting that in regards to floating point performance, "absolutely nobody cares outside of benchmarks."
"I absolutely detest FP benchmarks, and I realize other people care deeply. I just think AVX-512 is exactly the wrong thing to do. It's a pet peeve of mine. It's a prime example of something Intel has done wrong, partly by just increasing the fragmentation of the market," Torvalds said.
I think he's absolutely right, and previously we didn't see how much
Intel was wasting its time making these AVX instructions because it's
gaping security flaws were not yet known. We just assumed that the more
sophisticated these floating-point instructions got, the more power they
must draw naturally. But previous generations of FP instructions stayed
well within the power envelope of the processor, whereas these AVX
instructions have been known to go well outside the standard power envelope.