openstack/deb-python-oslo.service
Code Issues Proposed changes

Optimization of waiting subprocesses in ProcessLauncher

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Because of eventlet bug "eventlet.green override of os.waitpid
returns immediately in all cases"(
https://bitbucket.org/eventlet/eventlet/issue/92/eventletgreen-override-of-oswaitpid)
in scope of fixing openstack bug "Excessive CPU usage in ProcessLauncher()'s wait loop"
(https://bugs.launchpad.net/oslo-incubator/+bug/109534) additional sleep was added.
Since this bug is resolved and openstack depends on eventlet >=0.16
excessive sleep was removed.

Change-Id: Ief30758ff429b4adc2265a8ed7ae34c5b8c60a34
This commit is contained in:
Marian Horban
2015-02-16 14:38:20 -05:00
parent 63bcbb0d67
commit aac8d79018
1 changed files with 4 additions and 12 deletions
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16
openstack/common/service.py
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@@ -199,16 +199,12 @@ class ServiceWrapper(object):
class ProcessLauncher(object): class ProcessLauncher(object):
def __init__(self, wait_interval=0.01): def __init__(self):
"""Constructor. """Constructor."""
:param wait_interval: The interval to sleep for between checks
of child process exit.
"""
self.children = {} self.children = {}
self.sigcaught = None self.sigcaught = None
self.running = True self.running = True
self.wait_interval = wait_interval
rfd, self.writepipe = os.pipe() rfd, self.writepipe = os.pipe()
self.readpipe = eventlet.greenio.GreenPipe(rfd, 'r') self.readpipe = eventlet.greenio.GreenPipe(rfd, 'r')
self.handle_signal() self.handle_signal()
@@ -333,8 +329,8 @@ class ProcessLauncher(object):
def _wait_child(self): def _wait_child(self):
try: try:
# Don't block if no child processes have exited # Block while any of child processes have exited
pid, status = os.waitpid(0, os.WNOHANG) pid, status = os.waitpid(0, 0)
if not pid: if not pid:
return None return None
except OSError as exc: except OSError as exc:
@@ -363,10 +359,6 @@ class ProcessLauncher(object):
while self.running: while self.running:
wrap = self._wait_child() wrap = self._wait_child()
if not wrap: if not wrap:
# Yield to other threads if no children have exited
# Sleep for a short time to avoid excessive CPU usage
# (see bug #1095346)
eventlet.greenthread.sleep(self.wait_interval)
continue continue
while self.running and len(wrap.children) < wrap.workers: while self.running and len(wrap.children) < wrap.workers:
self._start_child(wrap) self._start_child(wrap)