Messages in this thread | | | Date | Tue, 26 May 2020 15:54:22 -0400 | From | Joel Fernandes <> | Subject | Re: [PATCH 03/10] rcu: Make locking explicit in do_nocb_deferred_wakeup_common() |
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On Wed, May 13, 2020 at 06:47:07PM +0200, Frederic Weisbecker wrote: > It can either be called inline (locally or CPU hotplug locked) when > rdp->nocb_defer_wakeup is pending or from the nocb timer. In both cases > the rdp is offlined and we want to take the nocb lock. > > Clarify the locking rules and expectations.
And you did inline the code in the locking helper already as I was suggesting in 01/10. :-) So that's settled ;-)
thanks,
- Joel
> > Signed-off-by: Frederic Weisbecker <frederic@kernel.org> > Cc: Paul E. McKenney <paulmck@kernel.org> > Cc: Josh Triplett <josh@joshtriplett.org> > Cc: Steven Rostedt <rostedt@goodmis.org> > Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > Cc: Lai Jiangshan <jiangshanlai@gmail.com> > Cc: Joel Fernandes <joel@joelfernandes.org> > --- > kernel/rcu/tree_plugin.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h > index 1d22b16c03e0..1dd3fdd675a1 100644 > --- a/kernel/rcu/tree_plugin.h > +++ b/kernel/rcu/tree_plugin.h > @@ -2142,9 +2142,9 @@ static void do_nocb_deferred_wakeup_common(struct rcu_data *rdp) > unsigned long flags; > int ndw; > > - rcu_nocb_lock_irqsave(rdp, flags); > + raw_spin_lock_irqsave(&rdp->nocb_lock, flags); > if (!rcu_nocb_need_deferred_wakeup(rdp)) { > - rcu_nocb_unlock_irqrestore(rdp, flags); > + raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags); > return; > } > ndw = READ_ONCE(rdp->nocb_defer_wakeup); > -- > 2.25.0 >
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