On Fri 26-02-21 16:56:28, Tim Chen wrote: > > > On 2/26/21 12:52 AM, Michal Hocko wrote: > > >> > >> Michal, > >> > >> Let's take an extreme case where memcg 1 always generate the > >> first event and memcg 2 generates the rest of 128*8-1 events > >> and the pattern repeat. > > > > I do not follow. Events are per-memcg, aren't they? > > __this_cpu_read(memcg->vmstats_percpu->targets[target]); > > [...] > > __this_cpu_write(memcg->vmstats_percpu->targets[target], next); > > > > You are right. My previous reasoning is incorrect as the sampling is done per memcg. > I'll do some additional debugging on why memcg is not on the tree. OK, thanks for the confirmation. I think we want to do 2 things. Remove the soft limit specific threshold and stay with a single one and recognize THPs. -- Michal Hocko SUSE Labs