Re: [PATCH v3 tip/core/rcu 1/9] rcu: Add call_rcu_tasks()

Lai Jiangshan
2014-08-04T01:27:30Z

On 08/01/2014 05:55 AM, Paul E. McKenney wrote:
> + rcu_read_lock();
> + for_each_process_thread(g, t) {
> + if (t != current && ACCESS_ONCE(t->on_rq) &&
> + !is_idle_task(t)) {
> + get_task_struct(t);
> + t->rcu_tasks_nvcsw = ACCESS_ONCE(t->nvcsw);
> + ACCESS_ONCE(t->rcu_tasks_holdout) = 1;
> + list_add(&t->rcu_tasks_holdout_list,
> + &rcu_tasks_holdouts);

This loop will collect all the runnable tasks. It is too much tasks.
Is it possible to collect only on_cpu tasks or PREEMPT_ACTIVE tasks?
It seems hard to achieve it.