On Fri, Jul 12, 2019 at 11:43:17AM +0800, 王贇 wrote: > > > On 2019/7/11 下午9:47, Peter Zijlstra wrote: > [snip] > >> + rcu_read_lock(); > >> + memcg = mem_cgroup_from_task(p); > >> + if (idx != -1) > >> + this_cpu_inc(memcg->stat_numa->locality[idx]); > > > > I thought cgroups were supposed to be hierarchical. That is, if we have: > > > > R > > / \ > > A > > /\ > > B > > \ > > t1 > > > > Then our task t1 should be accounted to B (as you do), but also to A and > > R. > > I get the point but not quite sure about this... > > Not like pages there are no hierarchical limitation on locality, also tasks You can use cpusets to affect that. > running in a particular group have no influence to others, not to mention the > extra overhead, does it really meaningful to account the stuff hierarchically? AFAIU it's a requirement of cgroups to be hierarchical. All our other cgroup accounting is like that.
