获得进程内存使用量的Python脚本

#!/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:  P@draigBrady.com
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/$pid/statm for
2.6 kernels up to and including 2.6.9.
There it represented the total file backed extent
V1.4      23 Nov 2006     Remove total from output as it's meaningless
(the shared values overlap with other programs).
Display the shared column. This extra info is
useful, especially as it overlaps between programs.
V1.5      26 Mar 2007     Remove redundant recursion from human()
V1.6      05 Jun 2007     Also report number of processes with a given name.
Patch from riccardo.murri@gmail.com
V1.7      20 Sep 2007     Use PSS from /proc/$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/$pid/smaps
as otherwise could match libraries causing a crash.
Patch from patrice.bouchand.fedora@gmail.com
V1.9      20 Feb 2008     Fix invalid values reported when PSS is available.
Reported by Andrey Borzenkov <arvidjaar@mail.ru>
V3.3      24 Jun 2014
http://github.com/pixelb/scripts/commits/master/scripts/ps_mem.py
Notes:
#
All interpreted programs where the interpreter is started
by the shell or with env, will be merged to the interpreter
(as that's what's given to exec). For e.g. all python programs
starting with "#!/usr/bin/env python" will be grouped under python.
You can change this by using the full command line but that will
have the undesirable affect of splitting up programs started with
differing parameters (for e.g. mingetty tty[1-6]).
#
For 2.6 kernels up to and including 2.6.13 and later 2.4 redhat kernels
(rmap vm without smaps) it can not be accurately determined how many pages
are shared between processes in general or within a program in our case:
http://lkml.org/lkml/2005/7/6/250
A warning is printed if overestimation is possible.
In addition for 2.6 kernels up to 2.6.9 inclusive, the shared
value in /proc/$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 kernelver():
    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""&quot;
    kv = kernelver()
    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 )</pre>