From 69031e3a6dc701b24e7dedfb56735122076437be Mon Sep 17 00:00:00 2001
From: Gyu-Ho Lee <gyuhox@gmail.com>
Date: Tue, 3 Oct 2017 15:06:37 -0700
Subject: [PATCH] clientv3/ordering: acquire setPrevRev mutex only when needed

Signed-off-by: Gyu-Ho Lee <gyuhox@gmail.com>
---
 clientv3/ordering/kv.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/clientv3/ordering/kv.go b/clientv3/ordering/kv.go
index e8bf07b8c..11c343091 100644
--- a/clientv3/ordering/kv.go
+++ b/clientv3/ordering/kv.go
@@ -43,10 +43,10 @@ func (kv *kvOrdering) getPrevRev() int64 {
 
 func (kv *kvOrdering) setPrevRev(currRev int64) {
 	prevRev := kv.getPrevRev()
-	kv.revMu.Lock()
-	defer kv.revMu.Unlock()
 	if currRev > prevRev {
+		kv.revMu.Lock()
 		kv.prevRev = currRev
+		kv.revMu.Unlock()
 	}
 }