diff options
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 75110ea75d01..d15cdab6aeb4 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -606,20 +606,28 @@ static void rcu_read_unlock_special(struct task_struct *t) local_irq_save(flags); irqs_were_disabled = irqs_disabled_flags(flags); if (preempt_bh_were_disabled || irqs_were_disabled) { + bool exp; + struct rcu_data *rdp = this_cpu_ptr(&rcu_data); + struct rcu_node *rnp = rdp->mynode; + t->rcu_read_unlock_special.b.exp_hint = false; + exp = (t->rcu_blocked_node && t->rcu_blocked_node->exp_tasks) || + (rdp->grpmask & rnp->expmask) || + tick_nohz_full_cpu(rdp->cpu); // Need to defer quiescent state until everything is enabled. - if (irqs_were_disabled && use_softirq && + if (exp && irqs_were_disabled && use_softirq && (in_irq() || !t->rcu_read_unlock_special.b.deferred_qs)) { // Using softirq, safe to awaken, and we get // no help from enabling irqs, unlike bh/preempt. raise_softirq_irqoff(RCU_SOFTIRQ); - } else if (irqs_were_disabled && !use_softirq && + } else if (exp && irqs_were_disabled && !use_softirq && !t->rcu_read_unlock_special.b.deferred_qs) { // Safe to awaken and we get no help from enabling // irqs, unlike bh/preempt. invoke_rcu_core(); } else { // Enabling BH or preempt does reschedule, so... + // Also if no expediting or NO_HZ_FULL, slow is OK. set_tsk_need_resched(current); set_preempt_need_resched(); } |