[PATCH 6/8] rcu: call rcu_read_unlock_special() in rcu_preempt_check_callbacks()

[Lai Jiangshan <laijs@cn.fujitsu.com>]

if rcu_read_unlock_special() is deferred, we can invoke it earlier
in the schedule-tick.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
 kernel/rcutree_plugin.h |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 997b424..c9ff9f1 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -684,8 +684,11 @@ static void rcu_preempt_check_callbacks(int cpu)
 {
 	struct task_struct *t = current;
 
-	if (t->rcu_read_lock_nesting == 0) {
+	if (t->rcu_read_lock_nesting == 0 ||
+	    t->rcu_read_lock_nesting == INT_MIN) {
 		rcu_preempt_qs(cpu);
+		if (t->rcu_read_unlock_special)
+			rcu_read_unlock_special(t, false);
 		return;
 	}
 	if (t->rcu_read_lock_nesting > 0 &&
-- 
1.7.4.4