On Wed, Aug 03, 2016 at 09:09:25AM +0200, David Hildenbrand wrote: [...] > > > > > Other architectures are not > > > > > +# supported yet. > > > > > > > > What if we provide a generic comparison function that does like > > > > the following pseudocode: > > > > > > > > def basic_comparison(modela, modelb): > > > > if modela.name == modelb.name: > > > > if modela.props == modelb.props: > > > > return "identical", [] > > > > else: > > > > #XXX: maybe add some extra logic to check if > > > > # modela.props is a subset or superset of modelb.props? > > > > return "incompatible", set(modela.props.keys(), > > > > modelb.props.keys()) > > > > else: > > > > return "incompatible", ["type"] > > > > > > > > def full_comparison(modela, modelb): > > > > r,p = basic_comparison(modela, modelb) > > > > if r == "incompatible": > > > > try: > > > > modela = expand_cpu_model(modela, "full") > > > > modelb = expand_cpu_model(modelb, "full") > > > > except: > > > > # in case "full" expansion mode is not supported > > > > return r,p > > > > return basic_comparison(modela, modelb) > > > > > > > > > > While I agree that that would be nice to have, it doesn't fit for s390x > > > right > > > now: The result on s390x does not rely on features/name only, but > > > internal data > > > we don't want to expose. > > > > > > e.g. z13.2 and z13s are considered identically. > > > > > > z13 is a subset of z13.2, although they have exactly the same > > > features/properties (right now). It basically has to do with internal data > > > (e.g. address bus sizes for hamax as an example) > > > > > > (that's where we indictate "type" under "responsible-properties" - they > > > can > > > never be made identically, you have to baseline). > > > > Right, I don't mean it to be enough for all architectures, but as > > a basic implementation that is minimally useful when there's no > > arch-specific comparison function. > > Then the question would be: Is it better to have a wrong result than any > result? > As it doesn't work on s390x, there could also be a problem with other > architectures. > > Especially when comparing against "host", the name after expansion would give > no identication about runnability. And only living with > "incompatible" and "identical" might also not really be enough. > > While this could make sense, I'd suggest postponing such a basic comapare > function until other architectures support the basics (expanding to full) and > then see if this basic function would work for them (maybe x86 is a good > candidate once the expanded name would not be "host" anymore).
Agreed. After we have a x86 implementation, we can look into implementing a generic comparison function (but make it opt-in, instead of enabling it for all architectures at once). -- Eduardo
