Comment by frollogaston

The NUMA use cases exist, but given the rarity, I'd rather the default behavior not prioritize them. Currently you have to explicitly tell the system not to let a task use multiple nodes' resources, not just CPU/memory but also PCIe. Maaybe it's smart enough to avoid some cross-node usage, but it's a soft heuristic rather than a clear rule, which actually makes it more of a footgun than being dumb about it.

I would rather it be the other way around, never allow a single process to do anything cross-NUMA unless it asks for that, maybe even be stricter and require a process to opt into using anything but node0. These machines are big enough that you're not going to saturate node0 with random tasks, and you're only going to saturate the whole machine with a more deliberate workload.