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The point was that if userspace = has > conditionals based on the architecture it shouldn't have to figure it out= based > on the chipid, as this has been done by the kernel already. > >> because as you rightfully point out the kernel doesn't (currently at lea= st) >> care much about the implementation > > I still don't see how that value will ever be meaningful, there is no suc= h thing > as "all GPUs of a certain implementation regardless of architecture" have > something in common, is it? I don't think it's an issue that implementation field is only meaningful wh= en you get the architecture. That's pretty common for other IDs, e.g. PCI prod= uct ID is meaningless without having the vendor ID. You mentioned in an earlier email about the typing, but we could still have meaningful impl IDs fully typed like this: pub enum Arch { Turing(impl_id), Ampere(impl_id), ... } and some langauges can do better, e.g. TypeScript allow you to write enumn ArchId { Turing, Ampere, ... } enum TuringImplId { ... } enum AmpereImplId { ... } type Id =3D { arch: ArchId.Turing, impl: TuringImplId } | { arch: ArchId.Ampere, impl: AmpereImplId }; So I think it's a reasonable design to have it. > > But since you say "currently at least", are there any plans to give this = value > some meaning beyond being a unique counter for chips within a certain > architecture? > > If so, I think that'd be a horrible way to encode some chip commonality. True, but I think the chip ID is as bad as impl ID. Feature detections shou= ld use dedicated featuire detection mechanism, not looking up IDs directly. I.= e. we should have userspace not having to use either chip ID or impl ID as much a= s we can. That said, I do think looking up tables are unavoidable, for getting names = or applying some quirk fixes. And I agree with Alistair that if we include it, including impl ID is better than the chip ID, as we should rather not havin= g user space relying on an arbitrary encoded chip ID. Best, Gary