tests/etcdutil: reduce TestRandomKillEtcd test time

Signed-off-by: lhy1024 <admin@liudos.us>

pkg/utils/etcdutil/etcdutil_test.go

@@ -452,9 +452,26 @@ func (suite *loopWatcherTestSuite) TestLoadWithLimitChange() {
 	re := suite.Require()
 	re.NoError(failpoint.Enable("github.com/tikv/pd/pkg/utils/etcdutil/meetEtcdError", `return()`))
 	cache := make(map[string]struct{})
-	for i := 0; i < int(maxLoadBatchSize)*2; i++ {
-		suite.put(re, fmt.Sprintf("TestLoadWithLimitChange%d", i), "")
+
+	// create data
+	count := int(maxLoadBatchSize) * 2
+	var wg sync.WaitGroup
+	tasks := make(chan int, count)
+	for w := 0; w < 16; w++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for i := range tasks {
+				suite.put(re, fmt.Sprintf("TestLoadWithLimitChange%d", i), "")
+			}
+		}()
+	}
+	for i := 0; i < count; i++ {
+		tasks <- i
 	}
+	close(tasks)
+	wg.Wait()
+
 	watcher := NewLoopWatcher(
 		suite.ctx,
 		&suite.wg,