Created
March 5, 2021 09:30
-
-
Save khatwaniNikhil/147acdb23b99780b0a977dccf4246eee to your computer and use it in GitHub Desktop.
Python Script - Calculate stack memory used by a Java process (made changes to https://github.com/apangin/jstackmem)
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
sudo python ./jstackmem.py 2495 | |
#!/usr/bin/python | |
# -*- coding: utf-8 -*- | |
import os | |
import bisect | |
import re | |
import subprocess | |
import sys | |
if len(sys.argv) < 2: | |
print 'Calculate stack memory used by a Java process' | |
print 'Usage: python jstackmem.py <pid>' | |
sys.exit() | |
# Read memory map of the target process | |
try: | |
pid = sys.argv[1] | |
with open('/proc/' + pid + '/smaps') as f: | |
smaps = f.readlines() | |
except Exception, e: | |
print 'Failed to open process memory map' | |
print e | |
sys.exit() | |
# Parse memory map | |
last_addr = None | |
addr = [] | |
pss = [] | |
shared = [] | |
for line in smaps: | |
m = re.match('([0-9a-f]+)-([0-9a-f]+) (..).+', line) | |
if m: | |
last_addr = (int(m.group(1), 16) if m.group(3) == 'rw' | |
else None) | |
elif last_addr: | |
m = re.match('Pss: +([0-9]+) kB', line) | |
if m: | |
addr.append(last_addr) | |
pss.append(int(m.group(1))) | |
shared.append(False) | |
def demote(user_uid, user_gid): | |
def result(): | |
report_ids('starting demotion') | |
os.setgid(user_gid) | |
os.setuid(user_uid) | |
report_ids('finished demotion') | |
return result | |
def report_ids(msg): | |
print 'uid, gid = %d, %d; %s' % (os.getuid(), os.getgid(), msg) | |
# Match stack addresses from jstack output with the memory map | |
try: | |
stack_total = 0 | |
jstack = subprocess.Popen(['jstack', pid], | |
preexec_fn=demote(1004,1004), | |
stdout=subprocess.PIPE) | |
while True: | |
line = jstack.stdout.readline() | |
if not line: | |
break | |
m = re.match("\"([^\"]*)\" .+\[0x([0-9a-f]+)\]\n", line) | |
if m: | |
addr_index = bisect.bisect(addr, int(m.group(2), 16)) - 1 | |
if shared[addr_index]: | |
# Region already counted | |
print '%6d` %s' % (pss[addr_index], m.group(1)) | |
else: | |
print '%6d %s' % (pss[addr_index], m.group(1)) | |
stack_total += pss[addr_index] | |
shared[addr_index] = True | |
except Exception, e: | |
print 'Failed to execute jstack' | |
print e | |
sys.exit() | |
print '%6d (Total)' % stack_total |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment