On 7/25/18 11:38 AM, Eric W. Biederman wrote: > > Absolutely NOT. Global thresholds are exactly correct given the fact > you are running on a single kernel. > > Memory is not free (Even though we are swimming in enough of it memory > rarely matters). One of the few remaining challenges is for containers > is finding was to limit resources in such a way that one application > does not mess things up for another container during ordinary usage. > > It looks like the neighbour tables absolutely are that kind of problem, > because the artificial limits are too strict. Completely giving up on > limits does not seem right approach either. We need to fix the limits > we have (perhaps making them go away entirely), not just apply a > band-aid. Let's get to the bottom of this and make the system better.
Eric: yes, they all share the global resource of memory and there should be limits on how many entries a remote entity can create. Network namespaces can provide a separation such that one namespace does not disrupt networking in another. It is absolutely appropriate to do so. Your rigid stance is inconsistent given the basic meaning of a network namespace and the parallels to this same problem -- bridges, vxlans, and ip fragments. Only neighbor tables are not per-device or per namespace; your insistence on global limits is missing the mark and wrong.
