Input: evdev - Modify the process of closing the evdev device to use the synchronize_rcu_expedited interface to speed up the shutdown process.

deepin inclusion
categroy: performace

As Documentations saied:
	synchronize_rcu_expedited() instead
	of synchronize_rcu().  This reduces latency,
	but can increase CPU utilization, degrade
	real-time latency, and degrade energy efficiency.
use it to optimize the shutdown process by
our system developer report where some input dev shutdown
cost many XXms.
With the patched kernel, shutdown cost time from 5.96 to 5.11.

Tested-by: qiancheng <qiancheng@uniontech.com>
Signed-off-by: huangbibo <huangbibo@uniontech.com>
Signed-off-by: tuhaowen <tuhaowen@uniontech.com>
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>

Author: opsiff

drivers/input/evdev.c

@@ -383,7 +383,13 @@ static void evdev_detach_client(struct evdev *evdev,
 	spin_lock(&evdev->client_lock);
 	list_del_rcu(&client->node);
 	spin_unlock(&evdev->client_lock);
-	synchronize_rcu();
+
+	if (system_state == SYSTEM_HALT ||
+		system_state == SYSTEM_POWER_OFF ||
+		system_state == SYSTEM_RESTART)
+		synchronize_rcu_expedited();
+	else
+		synchronize_rcu();
 }
 
 static int evdev_open_device(struct evdev *evdev)