November
19
Python: Script to break down what is using memory / RAM
#!/usr/bin/env python
# Try to determine how much RAM is currently being used per program.
# Note per _program_, not per process. So for example this script
# will report RAM used by all httpd process together. In detail it reports:
# sum(private RAM for program processes) + sum(Shared RAM for program processes)
# The shared RAM is problematic to calculate, and this script automatically
# selects the most accurate method available for your kernel.
# Licence: LGPLv2
# Author: [email protected]
# Source: http://www.pixelbeat.org/scripts/ps_mem.py
# V1.0 06 Jul 2005 Initial release
# V1.1 11 Aug 2006 root permission required for accuracy
# V1.2 08 Nov 2006 Add total to output
# Use KiB,MiB,... for units rather than K,M,...
# V1.3 22 Nov 2006 Ignore shared col from /proc/$pid/statm for
# 2.6 kernels up to and including 2.6.9.
# There it represented the total file backed extent
# V1.4 23 Nov 2006 Remove total from output as it's meaningless
# (the shared values overlap with other programs).
# Display the shared column. This extra info is
# useful, especially as it overlaps between programs.
# V1.5 26 Mar 2007 Remove redundant recursion from human()
# V1.6 05 Jun 2007 Also report number of processes with a given name.
# Patch from [email protected]
# V1.7 20 Sep 2007 Use PSS from /proc/$pid/smaps if available, which
# fixes some over-estimation and allows totalling.
# Enumerate the PIDs directly rather than using ps,
# which fixes the possible race between reading
# RSS with ps, and shared memory with this program.
# Also we can show non truncated command names.
# V1.8 28 Sep 2007 More accurate matching for stats in /proc/$pid/smaps
# as otherwise could match libraries causing a crash.
# Patch from [email protected]
# V1.9 20 Feb 2008 Fix invalid values reported when PSS is available.
# Reported by Andrey Borzenkov <[email protected]>
# V3.3 24 Jun 2014
# http://github.com/pixelb/scripts/commits/master/scripts/ps_mem.py
# Notes:
#
# All interpreted programs where the interpreter is started
# by the shell or with env, will be merged to the interpreter
# (as that's what's given to exec). For e.g. all python programs
# starting with "#!/usr/bin/env python" will be grouped under python.
# You can change this by using the full command line but that will
# have the undesirable affect of splitting up programs started with
# differing parameters (for e.g. mingetty tty[1-6]).
#
# For 2.6 kernels up to and including 2.6.13 and later 2.4 redhat kernels
# (rmap vm without smaps) it can not be accurately determined how many pages
# are shared between processes in general or within a program in our case:
# http://lkml.org/lkml/2005/7/6/250
# A warning is printed if overestimation is possible.
# In addition for 2.6 kernels up to 2.6.9 inclusive, the shared
# value in /proc/$pid/statm is the total file-backed extent of a process.
# We ignore that, introducing more overestimation, again printing a warning.
# Since kernel 2.6.23-rc8-mm1 PSS is available in smaps, which allows
# us to calculate a more accurate value for the total RAM used by programs.
#
# Programs that use CLONE_VM without CLONE_THREAD are discounted by assuming
# they're the only programs that have the same /proc/$PID/smaps file for
# each instance. This will fail if there are multiple real instances of a
# program that then use CLONE_VM without CLONE_THREAD, or if a clone changes
# its memory map while we're checksumming each /proc/$PID/smaps.
#
# I don't take account of memory allocated for a program
# by other programs. For e.g. memory used in the X server for
# a program could be determined, but is not.
#
# FreeBSD is supported if linprocfs is mounted at /compat/linux/proc/
# FreeBSD 8.0 supports up to a level of Linux 2.6.16
import getopt
import time
import errno
import os
import sys
try:
# md5 module is deprecated on python 2.6
# so try the newer hashlib first
import hashlib
md5_new = hashlib.md5
except ImportError:
import md5
md5_new = md5.new
# The following exits cleanly on Ctrl-C or EPIPE
# while treating other exceptions as before.
def std_exceptions(etype, value, tb):
sys.excepthook = sys.__excepthook__
if issubclass(etype, KeyboardInterrupt):
pass
elif issubclass(etype, IOError) and value.errno == errno.EPIPE:
pass
else:
sys.__excepthook__(etype, value, tb)
sys.excepthook = std_exceptions
#
# Define some global variables
#
PAGESIZE = os.sysconf("SC_PAGE_SIZE") / 1024 #KiB
our_pid = os.getpid()
have_pss = 0
class Proc:
def __init__(self):
uname = os.uname()
if uname[0] == "FreeBSD":
self.proc = '/compat/linux/proc'
else:
self.proc = '/proc'
def path(self, *args):
return os.path.join(self.proc, *(str(a) for a in args))
def open(self, *args):
try:
return open(self.path(*args))
except (IOError, OSError):
val = sys.exc_info()[1]
if (val.errno == errno.ENOENT or # kernel thread or process gone
val.errno == errno.EPERM):
raise LookupError
raise
proc = Proc()
#
# Functions
#
def parse_options():
try:
long_options = ['split-args', 'help', 'total']
opts, args = getopt.getopt(sys.argv[1:], "shtp:w:", long_options)
except getopt.GetoptError:
sys.stderr.write(help())
sys.exit(3)
if len(args):
sys.stderr.write("Extraneous arguments: %s\n" % args)
sys.exit(3)
# ps_mem.py options
split_args = False
pids_to_show = None
watch = None
only_total = False
for o, a in opts:
if o in ('-s', '--split-args'):
split_args = True
if o in ('-t', '--total'):
only_total = True
if o in ('-h', '--help'):
sys.stdout.write(help())
sys.exit(0)
if o in ('-p',):
try:
pids_to_show = [int(x) for x in a.split(',')]
except:
sys.stderr.write(help())
sys.exit(3)
if o in ('-w',):
try:
watch = int(a)
except:
sys.stderr.write(help())
sys.exit(3)
return (split_args, pids_to_show, watch, only_total)
def help():
help_msg = 'Usage: ps_mem [OPTION]...\n' \
'Show program core memory usage\n' \
'\n' \
' -h, -help Show this help\n' \
' -p <pid>[,pid2,...pidN] Only show memory usage PIDs in the specified list\n' \
' -s, --split-args Show and separate by, all command line arguments\n' \
' -t, --total Show only the total value\n' \
' -w <N> Measure and show process memory every N seconds\n'
return help_msg
#(major,minor,release)
def kernel_ver():
kv = proc.open('sys/kernel/osrelease').readline().split(".")[:3]
last = len(kv)
if last == 2:
kv.append('0')
last -= 1
while last > 0:
for char in "-_":
kv[last] = kv[last].split(char)[0]
try:
int(kv[last])
except:
kv[last] = 0
last -= 1
return (int(kv[0]), int(kv[1]), int(kv[2]))
#return Private,Shared
#Note shared is always a subset of rss (trs is not always)
def getMemStats(pid):
global have_pss
mem_id = pid #unique
Private_lines = []
Shared_lines = []
Pss_lines = []
Rss = (int(proc.open(pid, 'statm').readline().split()[1])
* PAGESIZE)
if os.path.exists(proc.path(pid, 'smaps')): #stat
digester = md5_new()
for line in proc.open(pid, 'smaps').readlines(): #open
# Note we checksum smaps as maps is usually but
# not always different for separate processes.
digester.update(line.encode('latin1'))
if line.startswith("Shared"):
Shared_lines.append(line)
elif line.startswith("Private"):
Private_lines.append(line)
elif line.startswith("Pss"):
have_pss = 1
Pss_lines.append(line)
mem_id = digester.hexdigest()
Shared = sum([int(line.split()[1]) for line in Shared_lines])
Private = sum([int(line.split()[1]) for line in Private_lines])
#Note Shared + Private = Rss above
#The Rss in smaps includes video card mem etc.
if have_pss:
pss_adjust = 0.5 # add 0.5KiB as this avg error due to trunctation
Pss = sum([float(line.split()[1])+pss_adjust for line in Pss_lines])
Shared = Pss - Private
elif (2,6,1) <= kernel_ver() <= (2,6,9):
Shared = 0 #lots of overestimation, but what can we do?
Private = Rss
else:
Shared = int(proc.open(pid, 'statm').readline().split()[2])
Shared *= PAGESIZE
Private = Rss - Shared
return (Private, Shared, mem_id)
def getCmdName(pid, split_args):
cmdline = proc.open(pid, 'cmdline').read().split("\0")
if cmdline[-1] == '' and len(cmdline) > 1:
cmdline = cmdline[:-1]
path = proc.path(pid, 'exe')
try:
path = os.readlink(path)
# Some symlink targets were seen to contain NULs on RHEL 5 at least
# https://github.com/pixelb/scripts/pull/10, so take string up to NUL
path = path.split('\0')[0]
except OSError:
val = sys.exc_info()[1]
if (val.errno == errno.ENOENT or # either kernel thread or process gone
val.errno == errno.EPERM):
raise LookupError
raise
if split_args:
return " ".join(cmdline)
if path.endswith(" (deleted)"):
path = path[:-10]
if os.path.exists(path):
path += " [updated]"
else:
#The path could be have prelink stuff so try cmdline
#which might have the full path present. This helped for:
#/usr/libexec/notification-area-applet.#prelink#.fX7LCT (deleted)
if os.path.exists(cmdline[0]):
path = cmdline[0] + " [updated]"
else:
path += " [deleted]"
exe = os.path.basename(path)
cmd = proc.open(pid, 'status').readline()[6:-1]
if exe.startswith(cmd):
cmd = exe #show non truncated version
#Note because we show the non truncated name
#one can have separated programs as follows:
#584.0 KiB + 1.0 MiB = 1.6 MiB mozilla-thunder (exe -> bash)
# 56.0 MiB + 22.2 MiB = 78.2 MiB mozilla-thunderbird-bin
return cmd
#The following matches "du -h" output
#see also human.py
def human(num, power="Ki", units=None):
if units is None:
powers = ["Ki", "Mi", "Gi", "Ti"]
while num >= 1000: #4 digits
num /= 1024.0
power = powers[powers.index(power)+1]
return "%.1f %sB" % (num, power)
else:
return "%.f" % ((num * 1024) / units)
def cmd_with_count(cmd, count):
if count > 1:
return "%s (%u)" % (cmd, count)
else:
return cmd
#Warn of possible inaccuracies
#2 = accurate & can total
#1 = accurate only considering each process in isolation
#0 = some shared mem not reported
#-1= all shared mem not reported
def shared_val_accuracy():
"""http://wiki.apache.org/spamassassin/TopSharedMemoryBug"""
kv = kernel_ver()
pid = os.getpid()
if kv[:2] == (2,4):
if proc.open('meminfo').read().find("Inact_") == -1:
return 1
return 0
elif kv[:2] == (2,6):
if os.path.exists(proc.path(pid, 'smaps')):
if proc.open(pid, 'smaps').read().find("Pss:")!=-1:
return 2
else:
return 1
if (2,6,1) <= kv <= (2,6,9):
return -1
return 0
elif kv[0] > 2 and os.path.exists(proc.path(pid, 'smaps')):
return 2
else:
return 1
def show_shared_val_accuracy( possible_inacc, only_total=False ):
level = ("Warning","Error")[only_total]
if possible_inacc == -1:
sys.stderr.write(
"%s: Shared memory is not reported by this system.\n" % level
)
sys.stderr.write(
"Values reported will be too large, and totals are not reported\n"
)
elif possible_inacc == 0:
sys.stderr.write(
"%s: Shared memory is not reported accurately by this system.\n" % level
)
sys.stderr.write(
"Values reported could be too large, and totals are not reported\n"
)
elif possible_inacc == 1:
sys.stderr.write(
"%s: Shared memory is slightly over-estimated by this system\n"
"for each program, so totals are not reported.\n" % level
)
sys.stderr.close()
if only_total and possible_inacc != 2:
sys.exit(1)
def get_memory_usage( pids_to_show, split_args, include_self=False, only_self=False ):
cmds = {}
shareds = {}
mem_ids = {}
count = {}
for pid in os.listdir(proc.path('')):
if not pid.isdigit():
continue
pid = int(pid)
# Some filters
if only_self and pid != our_pid:
continue
if pid == our_pid and not include_self:
continue
if pids_to_show is not None and pid not in pids_to_show:
continue
try:
cmd = getCmdName(pid, split_args)
except LookupError:
#operation not permitted
#kernel threads don't have exe links or
#process gone
continue
try:
private, shared, mem_id = getMemStats(pid)
except RuntimeError:
continue #process gone
if shareds.get(cmd):
if have_pss: #add shared portion of PSS together
shareds[cmd] += shared
elif shareds[cmd] < shared: #just take largest shared val
shareds[cmd] = shared
else:
shareds[cmd] = shared
cmds[cmd] = cmds.setdefault(cmd, 0) + private
if cmd in count:
count[cmd] += 1
else:
count[cmd] = 1
mem_ids.setdefault(cmd, {}).update({mem_id:None})
#Add shared mem for each program
total = 0
for cmd in cmds:
cmd_count = count[cmd]
if len(mem_ids[cmd]) == 1 and cmd_count > 1:
# Assume this program is using CLONE_VM without CLONE_THREAD
# so only account for one of the processes
cmds[cmd] /= cmd_count
if have_pss:
shareds[cmd] /= cmd_count
cmds[cmd] = cmds[cmd] + shareds[cmd]
total += cmds[cmd] #valid if PSS available
sorted_cmds = sorted(cmds.items(), key=lambda x:x[1])
sorted_cmds = [x for x in sorted_cmds if x[1]]
return sorted_cmds, shareds, count, total
def print_header():
sys.stdout.write(" Private + Shared = RAM used\tProgram\n\n")
def print_memory_usage(sorted_cmds, shareds, count, total):
for cmd in sorted_cmds:
sys.stdout.write("%9s + %9s = %9s\t%s\n" %
(human(cmd[1]-shareds[cmd[0]]),
human(shareds[cmd[0]]), human(cmd[1]),
cmd_with_count(cmd[0], count[cmd[0]])))
if have_pss:
sys.stdout.write("%s\n%s%9s\n%s\n" %
("-" * 33, " " * 24, human(total), "=" * 33))
def verify_environment():
if os.geteuid() != 0:
sys.stderr.write("Sorry, root permission required.\n")
if __name__ == '__main__':
sys.stderr.close()
sys.exit(1)
try:
kv = kernel_ver()
except (IOError, OSError):
val = sys.exc_info()[1]
if val.errno == errno.ENOENT:
sys.stderr.write(
"Couldn't access " + proc.path('') + "\n"
"Only GNU/Linux and FreeBSD (with linprocfs) are supported\n")
sys.exit(2)
else:
raise
if __name__ == '__main__':
split_args, pids_to_show, watch, only_total = parse_options()
verify_environment()
if not only_total:
print_header()
if watch is not None:
try:
sorted_cmds = True
while sorted_cmds:
sorted_cmds, shareds, count, total = get_memory_usage( pids_to_show, split_args )
if only_total and have_pss:
sys.stdout.write(human(total, units=1)+'\n')
elif not only_total:
print_memory_usage(sorted_cmds, shareds, count, total)
time.sleep(watch)
else:
sys.stdout.write('Process does not exist anymore.\n')
except KeyboardInterrupt:
pass
else:
# This is the default behavior
sorted_cmds, shareds, count, total = get_memory_usage( pids_to_show, split_args )
if only_total and have_pss:
sys.stdout.write(human(total, units=1)+'\n')
elif not only_total:
print_memory_usage(sorted_cmds, shareds, count, total)
# We must close explicitly, so that any EPIPE exception
# is handled by our excepthook, rather than the default
# one which is reenabled after this script finishes.
sys.stdout.close()
vm_accuracy = shared_val_accuracy()
show_shared_val_accuracy( vm_accuracy, only_total )