Python Script - Calculate stack memory used by a Java process (made changes to https://github.com/apangin/jstackmem)

gistfile1.txt

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