Linus Torvalds (torvalds.delete@this.linux-foundation.org) on May 20, 2022 11:32 am wrote:
> Brendan (btrotter.delete@this.gmail.com) on May 20, 2022 4:06 am wrote:
> >
> > To me, supporting dissimilar CPUs (for both "different ISA" and "same ISA with different instruction
> > timings") is an interesting engineering challenge [...]
>
> That's an odd way to spell "stupid and pointless".
>
> We already know what the problem is. Intel already did the "expose that cores
> are different" thing in their desktop/laptop chips. It was an abject and fundamental
> failure that is basically unfixable, and Intel already disabled it.
>
> So no, it's not an "engineering challenge". It was a broken product. It's the
> same kind of "engineering challenge" that Itanium was. Just give it up.
>
> Linus

Impossible or merely painful?

Catch the unimplemented instruction.
Tag the process as fat core only.
Reschedule and restart the instruction