Merge tag 'leds-for-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j...

[linux.git] / kernel / rcu / tree_exp.h

diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index d40708e8c5d6e1f234ad508aa2cf60afa3e4e83c..0b2c2ad69629cdc5ee4fd74984d90179a9f7eafd 100644 (file)
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -212,7 +212,7 @@ static void __rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
                        raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
                        if (wake) {
                                smp_mb(); /* EGP done before wake_up(). */
-                               swake_up(&rsp->expedited_wq);
+                               swake_up_one(&rsp->expedited_wq);
                        }
                        break;
                }
@@ -472,6 +472,7 @@ static void sync_rcu_exp_select_node_cpus(struct work_struct *wp)
 static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
                                     smp_call_func_t func)
 {
+       int cpu;
        struct rcu_node *rnp;
 
        trace_rcu_exp_grace_period(rsp->name, rcu_exp_gp_seq_endval(rsp), TPS("reset"));
@@ -486,13 +487,20 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
                rnp->rew.rew_func = func;
                rnp->rew.rew_rsp = rsp;
                if (!READ_ONCE(rcu_par_gp_wq) ||
-                   rcu_scheduler_active != RCU_SCHEDULER_RUNNING) {
-                       /* No workqueues yet. */
+                   rcu_scheduler_active != RCU_SCHEDULER_RUNNING ||
+                   rcu_is_last_leaf_node(rsp, rnp)) {
+                       /* No workqueues yet or last leaf, do direct call. */
                        sync_rcu_exp_select_node_cpus(&rnp->rew.rew_work);
                        continue;
                }
                INIT_WORK(&rnp->rew.rew_work, sync_rcu_exp_select_node_cpus);
-               queue_work_on(rnp->grplo, rcu_par_gp_wq, &rnp->rew.rew_work);
+               preempt_disable();
+               cpu = cpumask_next(rnp->grplo - 1, cpu_online_mask);
+               /* If all offline, queue the work on an unbound CPU. */
+               if (unlikely(cpu > rnp->grphi))
+                       cpu = WORK_CPU_UNBOUND;
+               queue_work_on(cpu, rcu_par_gp_wq, &rnp->rew.rew_work);
+               preempt_enable();
                rnp->exp_need_flush = true;
        }
 
@@ -518,7 +526,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
        jiffies_start = jiffies;
 
        for (;;) {
-               ret = swait_event_timeout(
+               ret = swait_event_timeout_exclusive(
                                rsp->expedited_wq,
                                sync_rcu_preempt_exp_done_unlocked(rnp_root),
                                jiffies_stall);