| Date | Fri, 1 Aug 2014 17:53:10 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH v2 tip/core/rcu 01/10] rcu: Add call_rcu_tasks() |
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On 07/30, 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)) { > + t->rcu_tasks_nvcsw = ACCESS_ONCE(t->nvcsw); > + t->rcu_tasks_holdout = 1; > + list_add(&t->rcu_tasks_holdout_list, > + &rcu_tasks_holdouts); > + } > + } > + rcu_read_unlock();
Wait, unless I missed something this can't work...
The problem is, once the exiting task passes exit_notify() it can be removed from rcu lists.
Now suppose that (say) proc_exit_connector() has a probe, and this task has jumped into trampoline and it was preempted there.
No?
Oleg.
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