diff options
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tasks.h | 9 | ||||
| -rw-r--r-- | kernel/rcu/tree_nocb.h | 8 |
2 files changed, 16 insertions, 1 deletions
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index 6333f4ccf024..4d7ee95df06e 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -986,6 +986,15 @@ static bool rcu_tasks_is_holdout(struct task_struct *t) return false; /* + * t->on_rq && !t->se.sched_delayed *could* be considered sleeping but + * since it is a spurious state (it will transition into the + * traditional blocked state or get woken up without outside + * dependencies), not considering it such should only affect timing. + * + * Be conservative for now and not include it. + */ + + /* * Idle tasks (or idle injection) within the idle loop are RCU-tasks * quiescent states. But CPU boot code performed by the idle task * isn't a quiescent state. diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h index 97b99cd06923..16865475120b 100644 --- a/kernel/rcu/tree_nocb.h +++ b/kernel/rcu/tree_nocb.h @@ -554,13 +554,19 @@ static void __call_rcu_nocb_wake(struct rcu_data *rdp, bool was_alldone, rcu_nocb_unlock(rdp); wake_nocb_gp_defer(rdp, RCU_NOCB_WAKE_LAZY, TPS("WakeLazy")); - } else if (!irqs_disabled_flags(flags)) { + } else if (!irqs_disabled_flags(flags) && cpu_online(rdp->cpu)) { /* ... if queue was empty ... */ rcu_nocb_unlock(rdp); wake_nocb_gp(rdp, false); trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WakeEmpty")); } else { + /* + * Don't do the wake-up upfront on fragile paths. + * Also offline CPUs can't call swake_up_one_online() from + * (soft-)IRQs. Rely on the final deferred wake-up from + * rcutree_report_cpu_dead() + */ rcu_nocb_unlock(rdp); wake_nocb_gp_defer(rdp, RCU_NOCB_WAKE, TPS("WakeEmptyIsDeferred")); |