Merge pull request #64969 from mfojtik/volume-01-fix-allocations

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

volume: decrease memory allocations for debugging messages

**What this PR does / why we need it**:

<img width="1769" alt="screen shot 2018-06-11 at 13 15 31" src="https://user-images.githubusercontent.com/44136/41230128-ebf7233c-6d7e-11e8-899d-6251a5fde236.png">

On large clusters, where the glog is not running on V(5) using the format as: `glog.V(5).Infof(fmt.Sprintf(....))` will cause the code inside `Infof()` to be ran and generate a tons of memory allocations even if the output of those messages are not returned to the console...

This patch should reduce those calls and also the string allocations done by message generation.

**Release note**:
```release-note
NONE
```

pkg/controller/volume/attachdetach/reconciler/reconciler.go

@@ -257,13 +257,17 @@ func (rc *reconciler) attachDesiredVolumes() {
 	for _, volumeToAttach := range rc.desiredStateOfWorld.GetVolumesToAttach() {
 		if rc.actualStateOfWorld.VolumeNodeExists(volumeToAttach.VolumeName, volumeToAttach.NodeName) {
 			// Volume/Node exists, touch it to reset detachRequestedTime
-			glog.V(5).Infof(volumeToAttach.GenerateMsgDetailed("Volume attached--touching", ""))
+			if glog.V(5) {
+				glog.Infof(volumeToAttach.GenerateMsgDetailed("Volume attached--touching", ""))
+			}
 			rc.actualStateOfWorld.ResetDetachRequestTime(volumeToAttach.VolumeName, volumeToAttach.NodeName)
 			continue
 		}
 		// Don't even try to start an operation if there is already one running
 		if rc.attacherDetacher.IsOperationPending(volumeToAttach.VolumeName, "") {
-			glog.V(10).Infof("Operation for volume %q is already running. Can't start attach for %q", volumeToAttach.VolumeName, volumeToAttach.NodeName)
+			if glog.V(10) {
+				glog.Infof("Operation for volume %q is already running. Can't start attach for %q", volumeToAttach.VolumeName, volumeToAttach.NodeName)
+			}
 			continue
 		}
 
@@ -279,7 +283,9 @@ func (rc *reconciler) attachDesiredVolumes() {
 		}
 
 		// Volume/Node doesn't exist, spawn a goroutine to attach it
-		glog.V(5).Infof(volumeToAttach.GenerateMsgDetailed("Starting attacherDetacher.AttachVolume", ""))
+		if glog.V(5) {
+			glog.Infof(volumeToAttach.GenerateMsgDetailed("Starting attacherDetacher.AttachVolume", ""))
+		}
 		err := rc.attacherDetacher.AttachVolume(volumeToAttach.VolumeToAttach, rc.actualStateOfWorld)
 		if err == nil {
 			glog.Infof(volumeToAttach.GenerateMsgDetailed("attacherDetacher.AttachVolume started", ""))