1 files changed, 28 insertions, 8 deletions

diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 46d61b597731..f72eefab8543 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -29,6 +29,15 @@ static void rcu_exp_gp_seq_start(struct rcu_state *rsp)
 }
 
 /*
+ * Return then value that expedited-grace-period counter will have
+ * at the end of the current grace period.
+ */
+static __maybe_unused unsigned long rcu_exp_gp_seq_endval(struct rcu_state *rsp)
+{
+	return rcu_seq_endval(&rsp->expedited_sequence);
+}
+
+/*
  * Record the end of an expedited grace period.
  */
 static void rcu_exp_gp_seq_end(struct rcu_state *rsp)
@@ -366,21 +375,30 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
 	int ret;
 	struct rcu_node *rnp;
 
+	trace_rcu_exp_grace_period(rsp->name, rcu_exp_gp_seq_endval(rsp), TPS("reset"));
 	sync_exp_reset_tree(rsp);
+	trace_rcu_exp_grace_period(rsp->name, rcu_exp_gp_seq_endval(rsp), TPS("select"));
 	rcu_for_each_leaf_node(rsp, rnp) {
 		raw_spin_lock_irqsave_rcu_node(rnp, flags);
 
 		/* Each pass checks a CPU for identity, offline, and idle. */
 		mask_ofl_test = 0;
-		for_each_leaf_node_possible_cpu(rnp, cpu) {
+		for_each_leaf_node_cpu_mask(rnp, cpu, rnp->expmask) {
+			unsigned long mask = leaf_node_cpu_bit(rnp, cpu);
 			struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
+			struct rcu_dynticks *rdtp = per_cpu_ptr(&rcu_dynticks, cpu);
+			int snap;
 
-			rdp->exp_dynticks_snap =
-				rcu_dynticks_snap(rdp->dynticks);
 			if (raw_smp_processor_id() == cpu ||
-			    rcu_dynticks_in_eqs(rdp->exp_dynticks_snap) ||
-			    !(rnp->qsmaskinitnext & rdp->grpmask))
-				mask_ofl_test |= rdp->grpmask;
+			    !(rnp->qsmaskinitnext & mask)) {
+				mask_ofl_test |= mask;
+			} else {
+				snap = rcu_dynticks_snap(rdtp);
+				if (rcu_dynticks_in_eqs(snap))
+					mask_ofl_test |= mask;
+				else
+					rdp->exp_dynticks_snap = snap;
+			}
 		}
 		mask_ofl_ipi = rnp->expmask & ~mask_ofl_test;
 
@@ -394,7 +412,7 @@ static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
 		raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
 
 		/* IPI the remaining CPUs for expedited quiescent state. */
-		for_each_leaf_node_possible_cpu(rnp, cpu) {
+		for_each_leaf_node_cpu_mask(rnp, cpu, rnp->expmask) {
 			unsigned long mask = leaf_node_cpu_bit(rnp, cpu);
 			struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
 
@@ -417,6 +435,7 @@ retry_ipi:
 			    (rnp->expmask & mask)) {
 				/* Online, so delay for a bit and try again. */
 				raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
+				trace_rcu_exp_grace_period(rsp->name, rcu_exp_gp_seq_endval(rsp), TPS("selectofl"));
 				schedule_timeout_uninterruptible(1);
 				goto retry_ipi;
 			}
@@ -443,6 +462,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
 	struct rcu_node *rnp_root = rcu_get_root(rsp);
 	int ret;
 
+	trace_rcu_exp_grace_period(rsp->name, rcu_exp_gp_seq_endval(rsp), TPS("startwait"));
 	jiffies_stall = rcu_jiffies_till_stall_check();
 	jiffies_start = jiffies;
 
@@ -606,7 +626,7 @@ static void _synchronize_rcu_expedited(struct rcu_state *rsp,
 		rew.rew_rsp = rsp;
 		rew.rew_s = s;
 		INIT_WORK_ONSTACK(&rew.rew_work, wait_rcu_exp_gp);
-		schedule_work(&rew.rew_work);
+		queue_work(rcu_gp_wq, &rew.rew_work);
 	}
 
 	/* Wait for expedited grace period to complete. */