2025年11月27日 00:01, "Michal Hocko" <[email protected] mailto:[email protected]?to=%22Michal%20Hocko%22%20%3Cmhocko%40suse.com%3E > 写到:
> > On Wed 26-11-25 03:05:32, [email protected] wrote: > > > > > 2025年11月25日 20:55, "Michal Hocko" <[email protected] > > mailto:[email protected]?to=%22Michal%20Hocko%22%20%3Cmhocko%40suse.com%3E > > > 写到: > > > > > > > > On Tue 25-11-25 12:39:11, [email protected] wrote: > > > > > > > > My goal is implement dynamic memory reclamation for memcgs without > > limits, > > > triggered by specific conditions. > > > > > > For instance, with memcg A and memcg B both unlimited, when memcg A faces > > > high PSI pressure, ebpf control memcg B do some memory reclaim work when > > > it try charge. > > > > > Understood. Please also think whether this is already possible with > > existing interfaces and if not what are roadblocks in that direction. > > > > I think it's possible to implement a userspace program using the existing > > PSI userspace interfaces and the control interfaces provided by memcg to > > accomplish this task. > > However, this approach has several limitations: > > the entire process depends on the continuous execution of the userspace > > program, response latency is higher, and we cannot perform fine-grained > > operations on target memcg. > > > I will need to back these arguments by some actual numbers. Agree – I’ll implement a PoC show it. Best, Hui > > > > > Now that Roman has provided PSI eBPF functionality at > > > > https://lore.kernel.org/lkml/[email protected]/ > > Maybe we could add eBPF support to memcg as well, allowing us to implement > > the entire functionality directly in the kernel through eBPF. > > > His usecase is very specific to OOM handling and we have agreed that > this specific usecase is really tricky to achieve from userspace. I > haven't see sound arguments for this usecase yet. > -- > Michal Hocko > SUSE Labs >
