On Thu, Jul 21, 2022 at 12:04:31PM +0800, Chengming Zhou wrote: > @@ -871,13 +861,23 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, > clear |= TSK_MEMSTALL_RUNNING; > if (prev->in_iowait) > set |= TSK_IOWAIT; > + > + /* > + * Periodic aggregation shuts off if there is a period of no > + * task changes, so we wake it back up if necessary. However, > + * don't do this if the task change is the aggregation worker > + * itself going to sleep, or we'll ping-pong forever. > + */ > + if (unlikely((prev->flags & PF_WQ_WORKER) && > + wq_worker_last_func(prev) == psi_avgs_work)) > + wake_clock = false; > } > > psi_flags_change(prev, clear, set); > > iter = NULL; > while ((group = iterate_groups(prev, &iter)) && group != common) > - psi_group_change(group, cpu, clear, set, now, true); > + psi_group_change(group, cpu, clear, set, now, wake_clock); > > /* > * TSK_ONCPU is handled up to the common ancestor. If we're tasked Wait, there is another psi_group_change() below this, which handles the clearing of TSK_RUNNING for common ancestors. We don't want to wake those either, so it needs s/true/wake_clock/ as well.