From 4f2d4d03f3a1a0a277dd04ec2abcbee2d4018fa2 Mon Sep 17 00:00:00 2001
From: jiajunsu <jiajunsu@huawei.com>
Date: Wed, 16 May 2018 16:40:49 +0800
Subject: [PATCH] Remove args(os=False) in monkey_patch

The first patch introduced os=False is
https://review.openstack.org/#/c/11556/

But there is no explaination why nova should not monkey_patch `os`
module. The args(os=False) make nova process has to wait while calling
 os.(['fdopen', 'read', 'write', 'wait', 'waitpid', 'open'])
, which seems to be unnecessary.

For nova-compute running on Windows(Hyper-v), `os` module should not be
patched, because Windows pipes don't support non-blocking I/O. I add a
comment to note that.

[1] https://github.com/eventlet/eventlet/blob/v0.23.0/eventlet/green/os.py#L12

Change-Id: I8b456676a04b9066cb2b570060c0d95cd4fe69f8
---
 nova/test.py                      | 2 +-
 nova/tests/functional/__init__.py | 2 +-
 nova/utils.py                     | 8 ++++++--
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/nova/test.py b/nova/test.py
index ea7fa2d04779..4a7fefc8730b 100644
--- a/nova/test.py
+++ b/nova/test.py
@@ -22,7 +22,7 @@ inline callbacks.
 """
 
 import eventlet  # noqa
-eventlet.monkey_patch(os=False)
+eventlet.monkey_patch()
 
 import abc
 import copy
diff --git a/nova/tests/functional/__init__.py b/nova/tests/functional/__init__.py
index e74717f867e1..71f41e30f33e 100644
--- a/nova/tests/functional/__init__.py
+++ b/nova/tests/functional/__init__.py
@@ -22,4 +22,4 @@
 
 import eventlet
 
-eventlet.monkey_patch(os=False)
+eventlet.monkey_patch()
diff --git a/nova/utils.py b/nova/utils.py
index a890d3ea67a4..c544e326d827 100644
--- a/nova/utils.py
+++ b/nova/utils.py
@@ -1293,9 +1293,13 @@ def generate_hostid(host, project_id):
 def monkey_patch():
     if debugger.enabled():
         # turn off thread patching to enable the remote debugger
-        eventlet.monkey_patch(os=False, thread=False)
-    else:
+        eventlet.monkey_patch(thread=False)
+    elif os.name == 'nt':
+        # for nova-compute running on Windows(Hyper-v)
+        # pipes don't support non-blocking I/O
         eventlet.monkey_patch(os=False)
+    else:
+        eventlet.monkey_patch()
 
     # NOTE(rgerganov): oslo.context is storing a global thread-local variable
     # which keeps the request context for the current thread. If oslo.context