On 12/7/2018 3:21 PM, Valentin Schneider wrote: > Hi Steve, > > On 06/12/2018 21:28, Steve Sistare wrote: > [...] >> @@ -6778,20 +6791,22 @@ static void check_preempt_wakeup(struct rq *rq, >> struct task_struct *p, int wake_ >> update_misfit_status(NULL, rq); >> >> /* >> - * We must set idle_stamp _before_ calling idle_balance(), such that we >> - * measure the duration of idle_balance() as idle time. >> + * We must set idle_stamp _before_ calling try_steal() or >> + * idle_balance(), such that we measure the duration as idle time. >> */ >> rq_idle_stamp_update(rq); > > idle_balance() has a > > /* > * Do not pull tasks towards !active CPUs... > */ > if (!cpu_active(this_cpu)) > return 0; > > check which we probably want for stealing too, so we could hoist it up here > to cover both idle_balance() and try_steal().
try_steal() already checks cpu_active. I could hoist it. - Steve > >> new_tasks = idle_balance(rq, rf); >> + if (new_tasks == 0) >> + new_tasks = try_steal(rq, rf); >> >> if (new_tasks) >> rq_idle_stamp_clear(rq); >> >> /* >> - * Because idle_balance() releases (and re-acquires) rq->lock, it is >> - * possible for any higher priority task to appear. In that case we >> - * must re-start the pick_next_entity() loop. >> + * Because try_steal() and idle_balance() release (and re-acquire) >> + * rq->lock, it is possible for any higher priority task to appear. >> + * In that case we must re-start the pick_next_entity() loop. >> */ >> if (new_tasks < 0) >> return RETRY_TASK; > [...] >
