devstack/tools/mlock_report.py
Ian Wienand b02a43291c Handle disappearing pids in mlock_report.py
If a pid disappears on us while we're reading, we should just continue
on.

EnvironmentError is just an alias for OSError since Python 3.3, so use
the latter name. [0]

[0] https://docs.python.org/3/library/exceptions.html#OSError

Change-Id: I3a25cca328e1469f72c84a118a9691c1c0258bc4
Closes-Bug: #1926434
2021-04-28 16:31:17 +00:00

54 lines
1.5 KiB
Python

# This tool lists processes that lock memory pages from swapping to disk.
import re
import psutil
LCK_SUMMARY_REGEX = re.compile(
"^VmLck:\s+(?P<locked>[\d]+)\s+kB", re.MULTILINE)
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():
# sadly psutil does not expose locked pages info, that's why we
# iterate over the /proc/%pid/status files manually
try:
s = open("%s/%d/status" % (psutil.PROCFS_PATH, proc.pid), 'r')
with s:
for line in s:
result = LCK_SUMMARY_REGEX.search(line)
if result:
locked = int(result.group('locked'))
if locked:
mlock_users.append({'name': proc.name(),
'pid': proc.pid,
'locked': locked})
except OSError:
# pids can disappear, we're ok with that
continue
# 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()