> They definitely could have made avx512 instructions trigger a switch to p-cores,
That'd be an OS thing.
This is a problem that has been solved in the mainframe / supercomputing world and which was discussed in the BSD world a quarter of a century ago. It's simple, really.
Each CPU offers a list of supported features (cpuctl identify), and the scheduler keeps track of whether a program advertises use of certain features. If it does want features that some CPUs don't support, that process can't be scheduled on those CPUs.
I remember thinking about this way back when dual Nintendo cartridge Pentium motherboards came out. To experiment, I ran a Pentium III and a Celery on an adapter card, which, like talking about self hosting email, infuriated people who told me it can't be done. Different clock speeds, different CPU features, et cetera, worked, and worked well enough to wonder what scheduler changes would make using those different features work properly.
That'd be an OS thing.
This is a problem that has been solved in the mainframe / supercomputing world and which was discussed in the BSD world a quarter of a century ago. It's simple, really.
Each CPU offers a list of supported features (cpuctl identify), and the scheduler keeps track of whether a program advertises use of certain features. If it does want features that some CPUs don't support, that process can't be scheduled on those CPUs.
I remember thinking about this way back when dual Nintendo cartridge Pentium motherboards came out. To experiment, I ran a Pentium III and a Celery on an adapter card, which, like talking about self hosting email, infuriated people who told me it can't be done. Different clock speeds, different CPU features, et cetera, worked, and worked well enough to wonder what scheduler changes would make using those different features work properly.