diff options
Diffstat (limited to 'kernel/rcu/tree_plugin.h')
-rw-r--r-- | kernel/rcu/tree_plugin.h | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index aa64b035c24f..e3142ee35fc6 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -641,7 +641,8 @@ static void rcu_read_unlock_special(struct task_struct *t) expboost = (t->rcu_blocked_node && READ_ONCE(t->rcu_blocked_node->exp_tasks)) || (rdp->grpmask & READ_ONCE(rnp->expmask)) || - IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD) || + (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD) && + ((rdp->grpmask & READ_ONCE(rnp->qsmask)) || t->rcu_blocked_node)) || (IS_ENABLED(CONFIG_RCU_BOOST) && irqs_were_disabled && t->rcu_blocked_node); // Need to defer quiescent state until everything is enabled. @@ -821,6 +822,7 @@ void rcu_read_unlock_strict(void) if (irqs_disabled() || preempt_count() || !rcu_state.gp_kthread) return; rdp = this_cpu_ptr(&rcu_data); + rdp->cpu_no_qs.b.norm = false; rcu_report_qs_rdp(rdp); udelay(rcu_unlock_delay); } @@ -866,7 +868,7 @@ void rcu_all_qs(void) if (!raw_cpu_read(rcu_data.rcu_urgent_qs)) return; - preempt_disable(); + preempt_disable(); // For CONFIG_PREEMPT_COUNT=y kernels /* Load rcu_urgent_qs before other flags. */ if (!smp_load_acquire(this_cpu_ptr(&rcu_data.rcu_urgent_qs))) { preempt_enable(); @@ -928,10 +930,13 @@ static notrace bool rcu_preempt_need_deferred_qs(struct task_struct *t) return false; } -// Except that we do need to respond to a request by an expedited grace -// period for a quiescent state from this CPU. Note that requests from -// tasks are handled when removing the task from the blocked-tasks list -// below. +// Except that we do need to respond to a request by an expedited +// grace period for a quiescent state from this CPU. Note that in +// non-preemptible kernels, there can be no context switches within RCU +// read-side critical sections, which in turn means that the leaf rcu_node +// structure's blocked-tasks list is always empty. is therefore no need to +// actually check it. Instead, a quiescent state from this CPU suffices, +// and this function is only called from such a quiescent state. notrace void rcu_preempt_deferred_qs(struct task_struct *t) { struct rcu_data *rdp = this_cpu_ptr(&rcu_data); @@ -1234,8 +1239,11 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu) cpu != outgoingcpu) cpumask_set_cpu(cpu, cm); cpumask_and(cm, cm, housekeeping_cpumask(HK_TYPE_RCU)); - if (cpumask_empty(cm)) + if (cpumask_empty(cm)) { cpumask_copy(cm, housekeeping_cpumask(HK_TYPE_RCU)); + if (outgoingcpu >= 0) + cpumask_clear_cpu(outgoingcpu, cm); + } set_cpus_allowed_ptr(t, cm); mutex_unlock(&rnp->boost_kthread_mutex); free_cpumask_var(cm); |