[jpecar]

I'm baffled by the fact that NUMA is still an issue in 2026. My impression is that this was all solved back in dotcom era already on those big SUNs. At least in HPC we solved this already in mid 2000s. Why is supposedly modern world still wasting time on this? Kernel these days exposes just about everything you would ever want to know about a system topology and every runtime should be making use of that information. If it does not, I cannot consider it ready for this century.

[mickeyp]

Because numa topology is an optimisation problem with a wide solution space, and that its configuration and setup depends on the amount of physical cpus and cores; how the RAM is connected to which lanes; and on and on it goes.

> If it does not, I cannot consider it ready for this century.

Mhmm.

[inkyoto]

Sun was one of the few RISC design houses who stubbornly resisted NUMA in favour of SMP, which they have perfected in the hardware and in the software (Solaris). The «Solaris internals» book discusses the subject of SMP vs NUMA vs ccNUMA in the «Parallel systems architectures» section (3.2).

You might be thinking SGI who went in big on NUMA. IBM and HP have also built ccNUMA systems (e.g. HP Superdome and Superdome 2).

[sillywalk]

> those big SUNs

I'm pretty sure all the big Sun boxes were SMP, not NUMA, at least during the dot-com era. Not sure about later UltraSPARC T or M Series systems.

[itemize123]

what do you mean by this is solved?