On 5/8/2018 2:31 AM, Johannes Weiner wrote: > +static void psi_group_update(struct psi_group *group, int cpu, u64 now, > + unsigned int clear, unsigned int set) > +{ > + enum psi_state state = PSI_NONE; > + struct psi_group_cpu *groupc; > + unsigned int *tasks; > + unsigned int to, bo; > + > + groupc = per_cpu_ptr(group->cpus, cpu); > + tasks = groupc->tasks; > + > + /* Update task counts according to the set/clear bitmasks */ > + for (to = 0; (bo = ffs(clear)); to += bo, clear >>= bo) { > + int idx = to + (bo - 1); > + > + if (tasks[idx] == 0 && !psi_bug) { > + printk_deferred(KERN_ERR "psi: task underflow! cpu=%d idx=%d tasks=[%u %u %u %u]\n", > + cpu, idx, tasks[0], tasks[1], > + tasks[2], tasks[3]); > + psi_bug = 1; > + } > + tasks[idx]--; > + } > + for (to = 0; (bo = ffs(set)); to += bo, set >>= bo) > + tasks[to + (bo - 1)]++; > + > + /* Time in which tasks wait for the CPU */ > + state = PSI_NONE; > + if (tasks[NR_RUNNING] > 1) > + state = PSI_SOME; > + time_state(&groupc->res[PSI_CPU], state, now); > + > + /* Time in which tasks wait for memory */ > + state = PSI_NONE; > + if (tasks[NR_MEMSTALL]) { > + if (!tasks[NR_RUNNING] || > + (cpu_curr(cpu)->flags & PF_MEMSTALL)) > + state = PSI_FULL; > + else > + state = PSI_SOME; > + } > + time_state(&groupc->res[PSI_MEM], state, now); > + > + /* Time in which tasks wait for IO */ > + state = PSI_NONE; > + if (tasks[NR_IOWAIT]) { > + if (!tasks[NR_RUNNING]) > + state = PSI_FULL; > + else > + state = PSI_SOME; > + } > + time_state(&groupc->res[PSI_IO], state, now); > + > + /* Time in which tasks are non-idle, to weigh the CPU in summaries */ > + if (groupc->nonidle) > + groupc->nonidle_time += now - groupc->nonidle_start; > + groupc->nonidle = tasks[NR_RUNNING] || > + tasks[NR_IOWAIT] || tasks[NR_MEMSTALL]; > + if (groupc->nonidle) > + groupc->nonidle_start = now; > + > + /* Kick the stats aggregation worker if it's gone to sleep */ > + if (!delayed_work_pending(&group->clock_work)) This causes a crash when the work is scheduled before system_wq is up. In my case when the first schedule was called from kthreadd. And I had to do this to make it work. if (keventd_up() && !delayed_work_pending(&group->clock_work)) > + schedule_delayed_work(&group->clock_work, MY_LOAD_FREQ); > +} > + > +void psi_task_change(struct task_struct *task, u64 now, int clear, int set) > +{ > + struct cgroup *cgroup, *parent; unused variables Thanks, Vinayak -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html