On Tue 10-09-24 09:31:15, Davidlohr Bueso wrote: > On Mon, 09 Sep 2024, Michal Hocko wrote: > > > On Wed 04-09-24 09:27:40, Davidlohr Bueso wrote: > > > 1. Users who do not use memcg can benefit from proactive reclaim. > > > > It would be great to have some specific examples here. Is there a > > specific reason memcg is not used? > > I know cases of people wanting to use this to free up fast memory > without incurring in extra latency spikes before a promotion occurs. Please give us more information about those because this might have an impact on how the interface is shaped. E.g. we might need to plan for future extension. > I do not have details as to why memcg is not used. I am not saying this is crucial to clarify but it is a natural question. We have a ready interface to achieve preemptive reclaim, why not use that and introduce something new. A plausible argument could be that memcg interface is not NUMA aware and there are usecases that are focusing on NUMA balancing rather than workload memory footprint. > I can also see > this for virtual machines running on specific nodes, reclaiming "extra" > memory based on wss and qos, as well as potential hibernation optimizations. Do not virtual solutions have own ways to manage overcommit/memory balancing (memory balooning etc.)? Does such interface fall into the existing picture? -- Michal Hocko SUSE Labs
