devstack/tools/mlock_report.py

61 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(b".*\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))
raise
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()