From: Eric Dumazet <edumazet@google.com>
Date: Fri, 20 Oct 2017 11:29:56 -0700
Subject: tun: avoid extra timer schedule in tun_flow_cleanup()
Patch-mainline: v4.15-rc1
Git-commit: 81d98fa4df3d1683b3ef21e8a7a0ccac7874f0de
References: bsc#1109837

If tun_flow_cleanup() deleted all flows, no need to
arm the timer again. It will be armed next time
tun_flow_update() is called.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/tun.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -461,11 +461,14 @@ static void tun_flow_cleanup(unsigned lo
 
 		hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
 			unsigned long this_timer;
-			count++;
+
 			this_timer = e->updated + delay;
-			if (time_before_eq(this_timer, jiffies))
+			if (time_before_eq(this_timer, jiffies)) {
 				tun_flow_delete(tun, e);
-			else if (time_before(this_timer, next_timer))
+				continue;
+			}
+			count++;
+			if (time_before(this_timer, next_timer))
 				next_timer = this_timer;
 		}
 	}