On Thu, May 13, 2021 at 10:53:49AM -0700, Suren Baghdasaryan wrote: > +bool cgroup_psi_enabled(void) > +{ > + return (cgroup_feature_disable_mask & (1 << OPT_FEATURE_PRESSURE)) == 0; > +} > diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c > index cc25a3cff41f..c73efd7d4fba 100644 > --- a/kernel/sched/psi.c > +++ b/kernel/sched/psi.c > @@ -747,9 +747,12 @@ static struct psi_group *iterate_groups(struct task_struct *task, void **iter) > #ifdef CONFIG_CGROUPS > struct cgroup *cgroup = NULL; > > - if (!*iter) > + if (!*iter) { > + /* Skip to psi_system if per-cgroup accounting is disabled */ > + if (!cgroup_psi_enabled()) > + goto update_sys; > cgroup = task->cgroups->dfl_cgrp; > - else if (*iter == &psi_system) > + } else if (*iter == &psi_system) > return NULL; > else > cgroup = cgroup_parent(*iter); > @@ -758,6 +761,7 @@ static struct psi_group *iterate_groups(struct task_struct *task, void **iter) > *iter = cgroup; > return cgroup_psi(cgroup); > } > +update_sys: > #else > if (*iter) > return NULL; I'm confused; shouldn't that do the same as that #else branch? Also, can you pretty please make cgroup_psi_enabled() a static_key ?