Re: [RFC PATCH v3 0/4] Node Weights and Weighted Interleave

Michal Hocko
2023-11-03T16:59:09Z

On Thu 02-11-23 14:21:14, Gregory Price wrote:
[...]
> Only thing I'm not sure of is what happens if mempolicy is allowed to
> select a node that doesn't exist. I could hack up a contrived test, but
> i don't think the state is reachable at the moment.

There are two different kinds of doesn't exist. One is an offline node
and the other is one with a number higher than the config option allows.
Although we do have a concept of possible nodes N_POSSIBLE I do not
think we do enforce that in any user interface and we only reject nodes
outside of MAX_NODE.

The possible nodes concept is more about optimizing for real HW so that
we do not over shoot when the config allows a huge number of nodes while
only handful of them are actually used (which is the majority of cases).
--
Michal Hocko
SUSE Labs