#!/bin/sh
#
# Location:   http://www.groks.org/dirty-memory.sh
# Author:     Stephen Deasey <sdeasey@gmail.com>
# Time-stamp: "2008-11-01 03:34:30"
#
# Which shared libraries/objects are causing the most dirty memory
# (private + shared) accross all processes on the system (in kb)?
#
#     sudo dirty-memory
#
# As above, but only for the processes belonging to a single user:
#
#     dirty-memory $UID
#
# The second and third columns are the private and shared dirty memory, accross
# all processes in the system. The first column is the total of these two.
# The fourth column is the number of processes sharing this memory. The fifth
# column is the library, executable, heap, stack or mmapped file.
#
# Example output:
#
#   $ sudo dirty-memory | grep -v heap | tail
#   416   400     16   (70)    /lib/libdl-2.8.so
#   420   420     0    (1)     /dev/shm/pulse-shm-276328216
#   456   456     0    (1)     [stack]:/usr/bin/emacs-23.0.60:3519
#   536   536     0    (14)    /usr/lib/libbonobo-2.so.0.0.0
#   644   644     0    (1)     /usr/lib/xulrunner-1.9/libxul.so
#   660   644     16   (98)    /lib/ld-2.8.so
#   788   780     8    (98)    /lib/libc-2.8.so
#   904   904     0    (25)    /usr/lib/libORBit-2.so.0.1.0
#   4708  4       4704 (15)    /SYSV00000000
#   9768  9768    0    (1)     /usr/bin/emacs-23.0.60
#
# - libc and ld are linked into all (98) processes running on the system.
#
# - Emacs is using the most stack space at 456k.
#
# - libxul is the library causing the single largest chunk of dirty
#   memory, although it is only mapped into a single process.
#
# - libORBit is causing more dirty memory than libxul overall, but this
#   is because it is mapped into 25 processes.
#

function main {
    if [ $# = 0 ]; then
        awkmaps /proc/[1-9]*/smaps | sort -n
    else
        SMAPS=$(find /proc/[1-9]*/smaps -maxdepth 1 \
                  -uid $1 ! -samefile /proc/self/smaps ! -samefile /proc/$$/smaps \
                  -printf "%p ")
        awkmaps $SMAPS | sort -n
    fi
}

function awkmaps {

    exec awk '

    /[0-9a-f]+-[0-9a-f]+ / {

        current = (NF >= 6 ? $6 : "[heap]")

        if (current == "[heap]" || current == "[stack]") {
            pid = smapspid(FILENAME)
            current = current ":" exefile(pid) ":" pid
        }

        process[FILENAME, current] += 1
        if (process[FILENAME, current] == 1) {
            all[current] += 1
        }
    }

    /Private_Dirty/ {
        if ($2 > 0) {
            private[current] += $2
        }
    }

    /Shared_Dirty/ {
        if ($2 > 0) {
            shared[current] += $2
        }
    }

    END {
        for (so in all) {
            total = private[so] + shared[so]
            if (total > 0) {
                printf("%d	%d	%d	(%d)	%s\n",
                       total, private[so], shared[so], all[so], so)
            }
        }
    }

    function smapspid(smapsfile,    a) {
        split(smapsfile, a, "/")
        return a[3]
    }

    function exefile(pid,    lscmd) {
        lscmd = "ls -l /proc/" pid "/exe"
        lscmd | getline
        close(lscmd)

        return $10
    }
' $@
}

main "$@"