Re: [PATCH RFC] rcu/kfree: Do not request RCU when not needed

[Joel Fernandes]

> On Nov 2, 2022, at 2:32 PM, Paul E. McKenney <paulmck@xxxxxxxxxx> wrote:
> 
> On Wed, Nov 02, 2022 at 06:30:24PM +0100, Uladzislau Rezki wrote:
>>> 
>>> to wait for a GP. Or if the poll_state_synchronize_rcu(oldstate)) != 0
>>> queue_rcu_work().
>>> 
>> A small fix. If poll_state_synchronize_rcu(oldstate)) == 0 then
>> queue_rcu_work() since a GP is still in progress.
> 
> Both get_state_synchronize_rcu() and poll_state_synchronize_rcu()
> may be invoked from interrupt handlers.  And from NMI handlers,
> for that matter.

Thanks for clarifying. I meant to say cond_synchronize_rcu() cannot be called from interrupt context, but I made that comment before Vlad cooked his patch.

Thanks,

 - Joel


>                            Thanx, Paul