On Mon, Jun 27, 2022 at 4:53 PM Shakeel Butt <shakeelb@xxxxxxxxxx> wrote: > Am I understanding correctly that this 69.4% (or 73.7%) regression is > with cgroup v2? > > Eric did the experiments on v2 but on real hardware where the > performance impact was negligible. > > BTW do you see similar regression for tcp as well or just sctp? TCP_RR with big packets can show a regression as well. I gave this perf profile: 28.69% [kernel] [k] copy_user_enhanced_fast_string 16.13% [kernel] [k] intel_idle_irq 6.46% [kernel] [k] page_counter_try_charge 6.20% [kernel] [k] __sk_mem_reduce_allocated 5.68% [kernel] [k] try_charge_memcg 5.16% [kernel] [k] page_counter_cancel And this points to false sharing on (struct page_counter *)->usage I guess memcg had free lunch, because of per-socket cache, that we need to remove.