On Tue 24-09-19 13:23:49, Peter Zijlstra wrote: > On Tue, Sep 24, 2019 at 12:56:22PM +0200, Michal Hocko wrote: [...] > > To be honest I really fail to see why to object to a simple semantic > > that NUMA_NO_NODE imply all usable cpus. Could you explain that please? > > Because it feels wrong. The device needs to be _somewhere_. It simply > cannot be node-less. What if it doesn't have any numa preference for what ever reason? There is no other way to express that than NUMA_NO_NODE. Anyway, I am not going to argue more about this because it seems more of a discussion about "HW shouldn't be doing that although the specification allows that" which cannot really have any outcome except of "feels correct/wrong". If you really feel strongly about this then we should think of a proper way to prevent this to happen because an out-of-bound access is certainly not something we really want, right? -- Michal Hocko SUSE Labs