The io_counters is not available on OS X, 兼容处理

clients/client-psutil.py

@@ -206,6 +206,10 @@ def _disk_io():
     如果这里做连续性IO，那么普通机械硬盘写入到100Mb/s，那么也能造成硬盘长时间的等待。
     磁盘读写有误差：4k，8k ，https://stackoverflow.com/questions/34413926/psutil-vs-dd-monitoring-disk-i-o
     """
+    if "darwin" in sys.platform:
+        diskIO["read"] = 0
+        diskIO["write"] = 0
+    else:
         while True:
             # first get a list of all processes and disk io counters
             procs = [p for p in psutil.process_iter()]