From 952489020ea36aced3737079fa17eff2e37b4da7 Mon Sep 17 00:00:00 2001
From: Fedor Tarasenko <feodor.tarasenko@gmail.com>
Date: Mon, 25 May 2020 22:18:17 +0300
Subject: [PATCH] Fix an issue with high cpu usage caused by
 ironic-python-agent

Currently running of ipa-centos8-stable-ussuri image causes 100%
cpu usage while cleaning. Proposed change fixes this behavior and
significantly speeds up cleaning.

Change-Id: I2ba9a69f22b11830d8ff1bc346b17bf1a52f25b0
Story: #2007696
Task: #39809
---
 ironic_python_agent/agent.py                              | 2 +-
 .../fix-high-cpu-usage-eventlet-1dccf3b81dd42c47.yaml     | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)
 create mode 100644 releasenotes/notes/fix-high-cpu-usage-eventlet-1dccf3b81dd42c47.yaml

diff --git a/ironic_python_agent/agent.py b/ironic_python_agent/agent.py
index 7b1b3e8ea..5eb1e28dd 100644
--- a/ironic_python_agent/agent.py
+++ b/ironic_python_agent/agent.py
@@ -381,7 +381,7 @@ class IronicPythonAgent(base.ExecuteCommandMixin):
             self.heartbeater.start()
         try:
             while self.serve_api:
-                eventlet.sleep(0)
+                eventlet.sleep(0.1)
         except KeyboardInterrupt:
             LOG.info('Caught keyboard interrupt, exiting')
         self.api.stop()
diff --git a/releasenotes/notes/fix-high-cpu-usage-eventlet-1dccf3b81dd42c47.yaml b/releasenotes/notes/fix-high-cpu-usage-eventlet-1dccf3b81dd42c47.yaml
new file mode 100644
index 000000000..e77a68007
--- /dev/null
+++ b/releasenotes/notes/fix-high-cpu-usage-eventlet-1dccf3b81dd42c47.yaml
@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    Fixes an issue with high cpu usage caused by ironic-python-agent greenthread
+    eventlent implementation. 
+
+    Using eventlet.sleep(0.1) instead of eventlet.sleep(0) gives other processes
+    of IPA more cpu time to run.