memuse.py

memuse.py

#!/usr/bin/env python


# Try to determine how much RAM is currently being used per program.

# 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 changing comm= to args= below but that will
# have the undesirable affect of splitting up programs started with
# differing parameters (for e.g. mingetty tty[1-6]).
#
# For older 2.6 kernels 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.
#
# The shared calculation below will factor out shared text and
# libs etc. within a program, but not between programs. So there
# will always be some overestimation. This will be the same for
# all processes that just use libc for e.g. but more for others
# that use larger shared libs like gnome, kde etc.
#
# 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.
#
# This script assumes threads are already merged by ps

import sys, os, string
PAGESIZE=os.sysconf("SC_PAGE_SIZE")/1024 #KiB
our_pid=os.getpid()

def shared_val_accurate():
    """http://wiki.apache.org/spamassassin/TopSharedMemoryBug"""
    kernel_ver=open("/proc/sys/kernel/osrelease").readline()[:3]
    if kernel_ver == "2.4":
        if open("/proc/meminfo").read().find("Inact_") == -1:
            return 1
        return 0
    elif kernel_ver == "2.6":
        if os.path.exists("/proc/"+str(os.getpid())+"/smaps"):
            return 1
        return 0

def getShared(pid):
    if os.path.exists("/proc/"+str(pid)+"/smaps"):
        shared_lines=[line
                      for line in open("/proc/"+str(pid)+"/smaps").readlines()
                      if line.find("Shared")!=-1]
        return sum([int(line.split()[1]) for line in shared_lines])
    else:
        return int(open("/proc/"+str(pid)+"/statm").readline().split()[2])*PAGESIZE

cmds={}
shareds={}
for line in os.popen("ps -e -o rss=,pid=,comm=").readlines():
    size, pid, cmd = map(string.strip,line.strip().split(None,2))
    if int(pid) == our_pid:
        continue #no point counting this process
    try:
        shared=getShared(pid)
    except:
        continue #ps gone away
    if shareds.get(cmd):
        if shareds[cmd] < shared:
            shareds[cmd]=shared
    else:
        shareds[cmd]=shared
    #Note shared is always a subset of rss (trs is not always)
    cmds[cmd]=cmds.setdefault(cmd,0)+int(size)-shared

#Add max shared mem for each program
for cmd in cmds.keys():
    cmds[cmd]=cmds[cmd]+shareds[cmd]

sort_list = cmds.items()
sort_list.sort(lambda x,y:cmp(x[1],y[1]))
sort_list=filter(lambda x:x[1],sort_list) #get rid of zero sized processes (kernel threads)

#The following matches "du -h" output
def human(num, power="K"):
    powers=["K","M","G","T"]
    while num >= 1000:
        num /= 1024.0
        power=powers[powers.index(power)+1]
        human(num,power)
    return "%.1f%s" % (num,power)

for cmd in sort_list:
    print "%6s %s" % (human(cmd[1]), cmd[0])

#if not shared_val_accurate():
#    sys.stderr.write("\nWarning: Shared memory is not reported correctly by this system.\n")
#    sys.stderr.write("Values reported could be too large.\n")