To make the previous change more effective, these synchronized keywords need to go as well.

This change is safe because (i) those actions are read-only and (ii) if they produce data that's bit old, that isn't really noticeable.

core/src/main/java/hudson/model/AbstractProject.java

@@ -1115,7 +1115,7 @@ public abstract class AbstractProject<P extends AbstractProject<P,R>,R extends A
      * @see TransientProjectActionFactory
      */
     @Override
-    public synchronized List<Action> getActions() {
+    public List<Action> getActions() {
         // add all the transient actions, too
         List<Action> actions = new Vector<Action>(super.getActions());
         actions.addAll(transientActions);

core/src/main/java/hudson/model/labels/LabelAtom.java

@@ -94,7 +94,7 @@ public class LabelAtom extends Label implements Saveable {
      * should do so by implementing {@link LabelAtomProperty#getActions(LabelAtom)}.
      */
     @Override
-    public synchronized List<Action> getActions() {
+    public List<Action> getActions() {
         // add all the transient actions, too
         List<Action> actions = new Vector<Action>(super.getActions());
         actions.addAll(transientActions);