fix: deadlock if processes have different log_buffer (#252)

mmcv/runner/hooks/logger/text.py

@@ -98,13 +98,16 @@ class TextLoggerHook(LoggerHook):
         log_dict['iter'] = runner.inner_iter + 1
         # only record lr of the first param group
         log_dict['lr'] = runner.current_lr()[0]
+        memory = None
+        if torch.cuda.is_available():
+            memory = self._get_max_memory(runner)
         if mode == 'train':
             log_dict['time'] = runner.log_buffer.output['time']
             log_dict['data_time'] = runner.log_buffer.output['data_time']
 
             # statistic memory
-            if torch.cuda.is_available():
-                log_dict['memory'] = self._get_max_memory(runner)
+            if memory is not None:
+                log_dict['memory'] = memory
         for name, val in runner.log_buffer.output.items():
             if name in ['time', 'data_time']:
                 continue