Faça o download de um script python chamado ps_mem.py link .
Agora, execute o script:
sudo python ps_mem.py
A saída listará todos os pacotes abertos com sua memória usada: (esta é uma amostra minha)
$ sudo python ps_mem.py
Private + Shared = RAM used Program
180.0 KiB + 14.0 KiB = 194.0 KiB vnstatd
176.0 KiB + 22.5 KiB = 198.5 KiB atd
196.0 KiB + 21.5 KiB = 217.5 KiB cntlm
216.0 KiB + 23.0 KiB = 239.0 KiB irqbalance
204.0 KiB + 36.0 KiB = 240.0 KiB chrome-sandbox (2)
192.0 KiB + 50.0 KiB = 242.0 KiB cat (2)
176.0 KiB + 70.0 KiB = 246.0 KiB anvil
240.0 KiB + 29.0 KiB = 269.0 KiB bicon.bin
196.0 KiB + 104.0 KiB = 300.0 KiB sh (2)
272.0 KiB + 36.0 KiB = 308.0 KiB cron
292.0 KiB + 20.0 KiB = 312.0 KiB acpid
288.0 KiB + 38.0 KiB = 326.0 KiB upstart-socket-bridge [updated]
304.0 KiB + 35.5 KiB = 339.5 KiB rtkit-daemon
292.0 KiB + 61.0 KiB = 353.0 KiB bmws
332.0 KiB + 26.5 KiB = 358.5 KiB xinetd
292.0 KiB + 71.0 KiB = 363.0 KiB log
344.0 KiB + 20.5 KiB = 364.5 KiB gpg-agent
320.0 KiB + 56.0 KiB = 376.0 KiB gnome-pty-helper (2)
364.0 KiB + 15.5 KiB = 379.5 KiB ssh-agent
316.0 KiB + 82.5 KiB = 398.5 KiB dovecot
364.0 KiB + 40.5 KiB = 404.5 KiB upstart-udev-bridge [updated]
388.0 KiB + 37.0 KiB = 425.0 KiB dnsmasq
300.0 KiB + 164.0 KiB = 464.0 KiB pickup
348.0 KiB + 151.0 KiB = 499.0 KiB master
420.0 KiB + 83.5 KiB = 503.5 KiB dbus
472.0 KiB + 60.0 KiB = 532.0 KiB xrdp-sesman
512.0 KiB + 20.0 KiB = 532.0 KiB gbr3
504.0 KiB + 64.0 KiB = 568.0 KiB gvfsd-burn
520.0 KiB + 50.5 KiB = 570.5 KiB xrdp
552.0 KiB + 33.0 KiB = 585.0 KiB bluetoothd
440.0 KiB + 166.0 KiB = 606.0 KiB qmgr
528.0 KiB + 89.5 KiB = 617.5 KiB geoclue-master
592.0 KiB + 97.5 KiB = 689.5 KiB gvfs-afc-volume-monitor
660.0 KiB + 39.5 KiB = 699.5 KiB usbsrvd
664.0 KiB + 91.0 KiB = 755.0 KiB gvfs-gphoto2-volume-monitor
676.0 KiB + 86.0 KiB = 762.0 KiB dbus-launch (2)
712.0 KiB + 82.0 KiB = 794.0 KiB at-spi2-registryd
700.0 KiB + 115.5 KiB = 815.5 KiB at-spi-bus-launcher
788.0 KiB + 90.0 KiB = 878.0 KiB accounts-daemon
888.0 KiB + 152.0 KiB = 1.0 MiB gnome-vfs-daemon
744.0 KiB + 299.5 KiB = 1.0 MiB avahi-daemon (2)
336.0 KiB + 807.5 KiB = 1.1 MiB udevd (3)
976.0 KiB + 174.0 KiB = 1.1 MiB getty (6)
968.0 KiB + 183.0 KiB = 1.1 MiB gvfsd (2)
960.0 KiB + 199.5 KiB = 1.1 MiB sshd
1.1 MiB + 149.5 KiB = 1.3 MiB upowerd
1.2 MiB + 97.0 KiB = 1.3 MiB modem-manager
1.1 MiB + 152.0 KiB = 1.3 MiB gvfs-gdu-volume-monitor
776.0 KiB + 630.5 KiB = 1.4 MiB nxd
1.3 MiB + 108.0 KiB = 1.4 MiB nmbd
1.4 MiB + 45.0 KiB = 1.4 MiB rsyslogd
1.0 MiB + 400.0 KiB = 1.4 MiB udisks-daemon (2)
1.3 MiB + 175.0 KiB = 1.5 MiB indicator-application-service
1.4 MiB + 159.0 KiB = 1.5 MiB dconf-service (2)
1.5 MiB + 54.5 KiB = 1.5 MiB init [updated]
1.2 MiB + 397.0 KiB = 1.6 MiB telepathy-logger
1.4 MiB + 224.0 KiB = 1.6 MiB whoopsie
1.3 MiB + 356.5 KiB = 1.7 MiB ubuntu-geoip-provider
1.6 MiB + 112.5 KiB = 1.7 MiB gvfsd-trash
1.3 MiB + 488.0 KiB = 1.7 MiB sudo
1.8 MiB + 75.5 KiB = 1.9 MiB freshclam
1.6 MiB + 251.0 KiB = 1.9 MiB cupsd
656.0 KiB + 1.2 MiB = 1.9 MiB kdeinit4
1.7 MiB + 220.5 KiB = 1.9 MiB console-kit-daemon
1.8 MiB + 109.0 KiB = 1.9 MiB nacl_helper
1.7 MiB + 247.5 KiB = 2.0 MiB indicator-session-service
1.7 MiB + 300.0 KiB = 2.0 MiB unity-files-daemon
2.2 MiB + 94.0 KiB = 2.3 MiB polkitd
2.2 MiB + 136.5 KiB = 2.3 MiB gnome-keyring-daemon
2.0 MiB + 378.0 KiB = 2.4 MiB indicator-datetime-service
2.4 MiB + 69.5 KiB = 2.5 MiB gvfsd-metadata
2.5 MiB + 88.5 KiB = 2.6 MiB config
1.2 MiB + 1.4 MiB = 2.6 MiB winbindd (3)
2.1 MiB + 440.5 KiB = 2.6 MiB VBoxXPCOMIPCD
2.4 MiB + 218.5 KiB = 2.6 MiB gvfsd-http
2.2 MiB + 506.0 KiB = 2.7 MiB mission-control-5
2.4 MiB + 335.0 KiB = 2.7 MiB telepathy-salut
2.5 MiB + 332.5 KiB = 2.9 MiB gnome-fallback-mount-helper
2.4 MiB + 548.0 KiB = 2.9 MiB zeitgeist-daemon (2)
1.2 MiB + 1.7 MiB = 2.9 MiB klauncher
2.9 MiB + 111.5 KiB = 3.0 MiB arpwatch
2.8 MiB + 376.5 KiB = 3.2 MiB gdu-notification-daemon
3.0 MiB + 220.5 KiB = 3.2 MiB NetworkManager
2.8 MiB + 452.0 KiB = 3.3 MiB indicator-printers-service
3.0 MiB + 378.5 KiB = 3.4 MiB gnome-session
3.0 MiB + 440.0 KiB = 3.5 MiB gnome-screensaver
3.3 MiB + 195.5 KiB = 3.5 MiB timekpr
2.8 MiB + 720.0 KiB = 3.5 MiB lightdm (2)
3.4 MiB + 161.0 KiB = 3.6 MiB x2gocleansessio
3.3 MiB + 233.0 KiB = 3.6 MiB gvfsd-smb
3.1 MiB + 605.0 KiB = 3.7 MiB telepathy-indicator
2.6 MiB + 1.4 MiB = 4.0 MiB smbd (2)
4.1 MiB + 234.0 KiB = 4.3 MiB gconfd-2 (2)
3.9 MiB + 685.0 KiB = 4.5 MiB e-addressbook-factory
4.0 MiB + 770.0 KiB = 4.7 MiB pulseaudio
3.3 MiB + 1.8 MiB = 5.0 MiB goa-daemon
3.8 MiB + 1.4 MiB = 5.2 MiB zeitgeist-fts (2)
5.6 MiB + 317.5 KiB = 5.9 MiB indicator-sound-service
5.6 MiB + 491.0 KiB = 6.1 MiB bamfdaemon
5.6 MiB + 458.5 KiB = 6.1 MiB unity-lens-util
5.4 MiB + 759.0 KiB = 6.1 MiB nm-applet
6.1 MiB + 64.0 KiB = 6.2 MiB teamviewerd
6.1 MiB + 603.0 KiB = 6.7 MiB polkit-gnome-authentication-agent-1
5.8 MiB + 989.5 KiB = 6.8 MiB VBoxSVC
6.3 MiB + 582.5 KiB = 6.9 MiB update-notifier
6.5 MiB + 442.0 KiB = 7.0 MiB unity-scope-cal
6.3 MiB + 738.5 KiB = 7.0 MiB notify-osd
7.2 MiB + 38.0 KiB = 7.2 MiB glusterd
7.0 MiB + 433.0 KiB = 7.5 MiB dbus-daemon (4)
6.9 MiB + 625.0 KiB = 7.5 MiB system-service-
7.0 MiB + 522.5 KiB = 7.5 MiB colord
6.4 MiB + 2.2 MiB = 8.6 MiB postgres (5)
8.7 MiB + 552.0 KiB = 9.2 MiB unity-lens-vide
5.9 MiB + 3.3 MiB = 9.3 MiB kded4
3.3 MiB + 6.1 MiB = 9.4 MiB monitorix-httpd
8.7 MiB + 801.0 KiB = 9.5 MiB bash (2)
9.0 MiB + 577.5 KiB = 9.5 MiB unity-scope-cit
3.8 MiB + 6.1 MiB = 10.0 MiB /usr/bin/monito
9.7 MiB + 867.0 KiB = 10.5 MiB indicator-timek
3.9 MiB + 7.3 MiB = 11.2 MiB apache2 (6)
11.1 MiB + 602.5 KiB = 11.7 MiB gtk-window-decorator
11.8 MiB + 1.2 MiB = 13.0 MiB nxclient.bin
12.7 MiB + 835.0 KiB = 13.5 MiB python2.7
12.9 MiB + 1.2 MiB = 14.1 MiB unity-applications-daemon
14.3 MiB + 200.5 KiB = 14.5 MiB twistd
11.7 MiB + 3.0 MiB = 14.7 MiB empathy
13.5 MiB + 1.8 MiB = 15.4 MiB gnome-terminal (2)
3.1 MiB + 15.2 MiB = 18.2 MiB bmcapture
17.3 MiB + 2.5 MiB = 19.7 MiB uget-gtk
20.9 MiB + 336.5 KiB = 21.2 MiB indicator-messages-service
20.2 MiB + 1.1 MiB = 21.3 MiB gnome-settings-daemon
23.0 MiB + 718.0 KiB = 23.7 MiB unity-music-daemon
34.5 MiB + 314.0 KiB = 34.8 MiB gvfs-fuse-daemon (2)
39.0 MiB + 920.5 KiB = 39.9 MiB unity-scope-vid
41.4 MiB + 76.0 KiB = 41.5 MiB mysqld
40.1 MiB + 2.1 MiB = 42.2 MiB nxnode.bin
43.6 MiB + 1.0 MiB = 44.6 MiB unity-panel-service
45.1 MiB + 515.0 KiB = 45.6 MiB ajenti-panel
101.0 MiB + 3.9 MiB = 104.9 MiB nxserver.bin (2)
113.2 MiB + 5.4 MiB = 118.6 MiB rhythmbox
122.6 MiB + 7.3 MiB = 129.9 MiB okular
155.8 MiB + 1.7 MiB = 157.5 MiB thunderbird
156.1 MiB + 2.4 MiB = 158.5 MiB liferea
154.6 MiB + 5.4 MiB = 160.0 MiB nautilus
228.7 MiB + 10.4 MiB = 239.1 MiB Xorg
239.3 MiB + 1.3 MiB = 240.6 MiB remmina
252.6 MiB + 169.5 KiB = 252.8 MiB hud-service
365.8 MiB + 5.3 MiB = 371.0 MiB compiz
381.1 MiB + 81.3 MiB = 462.3 MiB chrome (15)
3.6 GiB + 32.7 MiB = 3.7 GiB VirtualBox (3)
---------------------------------
6.8 GiB
=================================
Se você preferir a GUI, pode usar o aplicativo system monitor . Procure por ele a partir do seu traço. Uma vez aberto, vá para a aba de processos.
