devstack/tools/mlock_report.py
Ihar Hrachyshka 2b4735f1b3 Added list of mlock-using processes to peakmem_tracker output
The change makes peakmem_tracker list processes that lock memory pages
from swapping to disk. It may be helpful when debugging oom-killer job
failures in gate in case when dstat shows that swap is not fully used
when oom-killer is triggered.

The peakmem_tracker service was renamed into memory_tracker to reflect
its new broader scope.

Needed-By: I5862d92478397eac2e61b8a61ce3437b698678be
Change-Id: I1dca120448ee87930fe903fd81277b58efaefc92
2017-03-05 15:50:59 +00:00

60 lines
1.7 KiB
Python
Executable File

#!/usr/bin/env python
# This tool lists processes that lock memory pages from swapping to disk.
import re
import subprocess
import psutil
SUMMARY_REGEX = re.compile(r".*\s+(?P<locked>[\d]+)\s+KB")
def main():
try:
print _get_report()
except Exception as e:
print "Failure listing processes locking memory: %s" % str(e)
def _get_report():
mlock_users = []
for proc in psutil.process_iter():
pid = proc.pid
# sadly psutil does not expose locked pages info, that's why we
# call to pmap and parse the output here
try:
out = subprocess.check_output(['pmap', '-XX', str(pid)])
except subprocess.CalledProcessError as e:
# 42 means process just vanished, which is ok
if e.returncode == 42:
continue
raise
last_line = out.splitlines()[-1]
# some processes don't provide a memory map, for example those
# running as kernel services, so we need to skip those that don't
# match
result = SUMMARY_REGEX.match(last_line)
if result:
locked = int(result.group('locked'))
if locked:
mlock_users.append({'name': proc.name(),
'pid': pid,
'locked': locked})
# produce a single line log message with per process mlock stats
if mlock_users:
return "; ".join(
"[%(name)s (pid:%(pid)s)]=%(locked)dKB" % args
# log heavy users first
for args in sorted(mlock_users, key=lambda d: d['locked'])
)
else:
return "no locked memory"
if __name__ == "__main__":
main()