openstack/swift
Code Issues Proposed changes

Prevent CPU spinning when there are no children

Browse Source 
If you deploy an object server but have no rings at all (and are using
servers-per-port), then the CPU will spin as it checks for child
processes since there are actually no child processes to check.

This patch adds a sleep so that the CPU doesn't spin.

Change-Id: Iece62367aa2481a21752144b1f4477a3713282fe
This commit is contained in:
John Dickinson 2016-07-20 11:09:35 -07:00
parent d9b765320d
commit 8733311857
1 changed files with 15 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
swift/common/wsgi.py
View File

@ -951,6 +951,7 @@ def run_wsgi(conf_path, app_section, *args, **kwargs):
loop_timeout = strategy.loop_timeout() loop_timeout = strategy.loop_timeout()
with Timeout(loop_timeout, exception=False): with Timeout(loop_timeout, exception=False):
try:
try: try:
pid, status = green_os.wait() pid, status = green_os.wait()
if os.WIFEXITED(status) or os.WIFSIGNALED(status): if os.WIFEXITED(status) or os.WIFSIGNALED(status):
@ -958,6 +959,14 @@ def run_wsgi(conf_path, app_section, *args, **kwargs):
except OSError as err: except OSError as err:
if err.errno not in (errno.EINTR, errno.ECHILD): if err.errno not in (errno.EINTR, errno.ECHILD):
raise raise
if err.errno == errno.ECHILD:
# If there are no children at all (ECHILD), then
# there's nothing to actually wait on. We sleep
# for a little bit to avoid a tight CPU spin
# and still are able to catch any KeyboardInterrupt
# events that happen. The value of 0.01 matches the
# value in eventlet's waitpid().
sleep(0.01)
except KeyboardInterrupt: except KeyboardInterrupt:
logger.notice('User quit') logger.notice('User quit')
running[0] = False running[0] = False