Not sure if you can trap on cpuid, bit the kernel does have control to which cpuid bits are exposed to your application
So requiring pinning to see all the bits could work, but then the issue is what happen if the affinity is changed. A static list of required capabilities in some ELF header would probably be better.
> A static list of required capabilities in some ELF header would probably be better.
I think I agree, the thing is that it's a kind-of security issue. I suggested pinning, because it requires CAP_SYS_NICE, which is a feature: If you allow apps to freely declare their usage, they will end up being scheduled not fairly, because system will stick them to P cores.
That being said, you could have indeed an ELF header mentioning since, and then ignore it if caller doesn't have CAP_SYS_NICE. I do feel using an ELF header for that is weird, but my knowledge of ELF is way too little to judge.
Another thing that could work is using file-system attributes or mode (like setuid), but I think FS support of attributes is at best spotty, and I doubt modes can be extended.
