On Sun, May 02, 2021 at 08:40:49PM -0700, Paul E. McKenney wrote: > @@ -634,6 +644,12 @@ do { \ > * sections, invocation of the corresponding RCU callback is deferred > * until after the all the other CPUs exit their critical sections. > * > + * In recent kernels, synchronize_rcu() and call_rcu() also wait for > + * regions of code with preemption disabled, including regions of code > + * with interrupts or softirqs disabled. If your kernel is old enough > + * for synchronize_sched() to be defined, only code enclosed within > + * rcu_read_lock() and rcu_read_unlock() are guaranteed to be waited for. > + * > * Note, however, that RCU callbacks are permitted to run concurrently > * with new RCU read-side critical sections. One way that this can happen > * is via the following sequence of events: (1) CPU 0 enters an RCU You still have "old enough" / "recent kernels" here. But maybe it's OK given that you added relevant version numbers elsewhere. Everything else looks great to me. Thanks, -- Michel "walken" Lespinasse