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.
s/offlined/offloaded/ thanks, - Joel > > Clarify the locking rules and expectations. > > Signed-off-by: Frederic Weisbecker <[email protected]> > Cc: Paul E. McKenney <[email protected]> > Cc: Josh Triplett <[email protected]> > Cc: Steven Rostedt <[email protected]> > Cc: Mathieu Desnoyers <[email protected]> > Cc: Lai Jiangshan <[email protected]> > Cc: Joel Fernandes <[email protected]> > --- > 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 >
