On Mon, Aug 25, 2025 at 07:57:28AM +0000, K Prateek Nayak wrote: > This led us down a rabbit hole of XTOPOLOGY vs TOPOEXT support, preferred So in order to save people the rabbit hole wandering each time they (or we) have to undertake, I think we should document what the whole logic and precedences are wrt CPUID leafs and topology. What should be done where and so on. And those commit messages have a lot of text which explains that and I think it would be worth the effort to start holding it down here Documentation/arch/x86/topology.rst No long texts, no big explanations - just the plain facts and what the current strategy is wrt to which CPUID leafs we parse for what in what order and so on. You could start the AMD side, it doesn't have to be exhaustive - just the facts from this rabbit hole trip. And then we'll keep extending it and filling out the details so that it is right there written down in one place. Makes sense? Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette