perf(config): ensure root keys of 'conf' config is atom

apps/emqx/src/emqx_config.erl

@@ -232,14 +232,14 @@ find_listener_conf(Type, Listener, KeyPath) ->
 put(Config) ->
     maps:fold(
         fun(RootName, RootValue, _) ->
-            ?MODULE:put([RootName], RootValue)
+            ?MODULE:put([atom(RootName)], RootValue)
         end,
         ok,
         Config
     ).
 
 erase(RootName) ->
-    persistent_term:erase(?PERSIS_KEY(?CONF, bin(RootName))),
+    persistent_term:erase(?PERSIS_KEY(?CONF, atom(RootName))),
     persistent_term:erase(?PERSIS_KEY(?RAW_CONF, bin(RootName))),
     ok.
 
@@ -689,9 +689,9 @@ do_get(Type, [], Default) ->
         false -> AllConf
     end;
 do_get(Type, [RootName], Default) ->
-    persistent_term:get(?PERSIS_KEY(Type, bin(RootName)), Default);
+    persistent_term:get(?PERSIS_KEY(Type, RootName), Default);
 do_get(Type, [RootName | KeyPath], Default) ->
-    RootV = persistent_term:get(?PERSIS_KEY(Type, bin(RootName)), #{}),
+    RootV = persistent_term:get(?PERSIS_KEY(Type, RootName), #{}),
     do_deep_get(Type, KeyPath, RootV, Default).
 
 do_put(Type, Putter, [], DeepValue) ->
@@ -705,7 +705,7 @@ do_put(Type, Putter, [], DeepValue) ->
 do_put(Type, Putter, [RootName | KeyPath], DeepValue) ->
     OldValue = do_get(Type, [RootName], #{}),
     NewValue = do_deep_put(Type, Putter, KeyPath, OldValue, DeepValue),
-    persistent_term:put(?PERSIS_KEY(Type, bin(RootName)), NewValue).
+    persistent_term:put(?PERSIS_KEY(Type, RootName), NewValue).
 
 do_deep_get(?CONF, KeyPath, Map, Default) ->
     atom_conf_path(