Высокое использование оперативной памяти в Ubuntu 16.04

У меня проблема с тех пор, как я обновился с 15.10 до 16.04 несколько дней назад: мой оперативный диск почти полностью заполнен!

У меня 8 ГБ оперативной памяти в моей системе, в настоящее время используется 6,9 ГБ (только Firefox открыт).

Я запустил скрипт ps_mem, который показывает следующее:

    Private  +   Shared  =  RAM used    Program 

  4.0 KiB +  10.0 KiB =  14.0 KiB   sh
  4.0 KiB +  12.5 KiB =  16.5 KiB   vmnet-bridge
  4.0 KiB +  20.5 KiB =  24.5 KiB   agetty
  8.0 KiB +  25.0 KiB =  33.0 KiB   vmnet-netifup (2)
  4.0 KiB +  31.5 KiB =  35.5 KiB   uuidd
  4.0 KiB +  35.0 KiB =  39.0 KiB   cgmanager
  4.0 KiB +  53.0 KiB =  57.0 KiB   indicator-bluetooth-service
  4.0 KiB +  60.0 KiB =  64.0 KiB   gvfsd-metadata
  4.0 KiB +  62.0 KiB =  66.0 KiB   gvfsd-burn
  4.0 KiB +  63.0 KiB =  67.0 KiB   gvfsd-fuse
 36.0 KiB +  32.0 KiB =  68.0 KiB   atd
  4.0 KiB +  64.5 KiB =  68.5 KiB   indicator-messages-service
  4.0 KiB +  68.0 KiB =  72.0 KiB   indicator-power-service
  4.0 KiB +  69.5 KiB =  73.5 KiB   sshd
 40.0 KiB +  46.0 KiB =  86.0 KiB   rtkit-daemon
  4.0 KiB +  86.5 KiB =  90.5 KiB   gvfsd-network
 68.0 KiB +  25.0 KiB =  93.0 KiB   vmware-authdlauncher
 80.0 KiB +  14.0 KiB =  94.0 KiB   acpid
  4.0 KiB +  90.0 KiB =  94.0 KiB   (sd-pam)
  4.0 KiB + 119.0 KiB = 123.0 KiB   timidity
  4.0 KiB + 122.0 KiB = 126.0 KiB   ModemManager
112.0 KiB +  35.5 KiB = 147.5 KiB   cron
  8.0 KiB + 157.0 KiB = 165.0 KiB   lightdm (2)
168.0 KiB +  27.5 KiB = 195.5 KiB   irqbalance
152.0 KiB +  57.5 KiB = 209.5 KiB   ibus-dconf
172.0 KiB +  47.5 KiB = 219.5 KiB   systemd-timesyncd
  4.0 KiB + 215.5 KiB = 219.5 KiB   evolution-addressbook-factory
168.0 KiB +  60.5 KiB = 228.5 KiB   gvfs-mtp-volume-monitor
156.0 KiB +  76.5 KiB = 232.5 KiB   accounts-daemon
140.0 KiB +  97.0 KiB = 237.0 KiB   vmnet-dhcpd (2)
200.0 KiB +  58.5 KiB = 258.5 KiB   upstart-file-bridge
164.0 KiB +  96.5 KiB = 260.5 KiB   upstart-udev-bridge
188.0 KiB +  87.0 KiB = 275.0 KiB   gvfsd-trash
188.0 KiB +  96.0 KiB = 284.0 KiB   gvfs-afc-volume-monitor
  4.0 KiB + 292.5 KiB = 296.5 KiB   evolution-source-registry
164.0 KiB + 145.0 KiB = 309.0 KiB   gvfsd-dnssd
272.0 KiB +  56.0 KiB = 328.0 KiB   gvfs-goa-volume-monitor
  4.0 KiB + 326.5 KiB = 330.5 KiB   evolution-calendar-factory
296.0 KiB +  52.0 KiB = 348.0 KiB   gpg-agent
248.0 KiB + 142.0 KiB = 390.0 KiB   gconfd-2
320.0 KiB +  73.0 KiB = 393.0 KiB   at-spi-bus-launcher
336.0 KiB +  58.0 KiB = 394.0 KiB   vmware-vmblock-
328.0 KiB +  71.0 KiB = 399.0 KiB   gvfs-gphoto2-volume-monitor
400.0 KiB +  18.0 KiB = 418.0 KiB   vmnet-natd
360.0 KiB +  92.5 KiB = 452.5 KiB   thermald
332.0 KiB + 137.5 KiB = 469.5 KiB   upstart-dbus-bridge (2)
416.0 KiB +  88.0 KiB = 504.0 KiB   at-spi2-registryd
376.0 KiB + 139.0 KiB = 515.0 KiB   avahi-daemon (2)
392.0 KiB + 124.0 KiB = 516.0 KiB   gvfsd
484.0 KiB +  40.5 KiB = 524.5 KiB   systemd-logind
428.0 KiB + 103.0 KiB = 531.0 KiB   deja-dup-monitor
488.0 KiB +  47.5 KiB = 535.5 KiB   rsyslogd
456.0 KiB +  81.0 KiB = 537.0 KiB   polkitd
156.0 KiB + 386.0 KiB = 542.0 KiB   dnsmasq (3)
432.0 KiB + 122.0 KiB = 554.0 KiB   ibus-engine-simple
544.0 KiB +  68.5 KiB = 612.5 KiB   sudo
484.0 KiB + 142.5 KiB = 626.5 KiB   upowerd
456.0 KiB + 195.0 KiB = 651.0 KiB   cups-browsed
476.0 KiB + 179.0 KiB = 655.0 KiB   evolution-addressbook-factory-subprocess
624.0 KiB +  41.5 KiB = 665.5 KiB   vmware-usbarbitrator
612.0 KiB +  55.0 KiB = 667.0 KiB   systemd-udevd
352.0 KiB + 339.0 KiB = 691.0 KiB   nmbd
664.0 KiB +  67.0 KiB = 731.0 KiB   dconf-service
508.0 KiB + 257.0 KiB = 765.0 KiB   indicator-application-service
700.0 KiB +  81.5 KiB = 781.5 KiB   indicator-session-service
568.0 KiB + 294.0 KiB = 862.0 KiB   indicator-sound-service
688.0 KiB + 281.0 KiB = 969.0 KiB   zeitgeist-datahub
688.0 KiB + 310.5 KiB = 998.5 KiB   whoopsie
680.0 KiB + 323.0 KiB =   1.0 MiB   libvirtd
456.0 KiB + 580.0 KiB =   1.0 MiB   window-stack-bridge
984.0 KiB + 100.0 KiB =   1.1 MiB   upstart
796.0 KiB + 316.0 KiB =   1.1 MiB   update-notifier
956.0 KiB + 177.0 KiB =   1.1 MiB   gvfs-udisks2-volume-monitor
924.0 KiB + 238.0 KiB =   1.1 MiB   polkit-gnome-authentication-agent-1
956.0 KiB + 234.0 KiB =   1.2 MiB   unity-fallback-mount-helper
  1.0 MiB + 191.5 KiB =   1.2 MiB   indicator-datetime-service
964.0 KiB + 360.0 KiB =   1.3 MiB   evolution-calendar-factory-subprocess (2)
  1.0 MiB + 331.5 KiB =   1.3 MiB   firewalld
  1.1 MiB + 289.5 KiB =   1.3 MiB   ibus-x11
940.0 KiB + 446.0 KiB =   1.4 MiB   notify-osd
  1.2 MiB + 277.0 KiB =   1.4 MiB   indicator-printers-service
  1.2 MiB + 264.0 KiB =   1.4 MiB   gnome-session-binary
  1.1 MiB + 331.0 KiB =   1.5 MiB   colord
  1.4 MiB +  67.5 KiB =   1.5 MiB   systemd-journald
  1.3 MiB + 284.5 KiB =   1.6 MiB   indicator-keyboard-service
  1.7 MiB + 142.5 KiB =   1.9 MiB   gnome-keyring-daemon
  1.4 MiB + 515.0 KiB =   1.9 MiB   zeitgeist-daemon
  1.8 MiB + 325.0 KiB =   2.1 MiB   nm-applet
  1.9 MiB + 203.5 KiB =   2.1 MiB   ibus-daemon
  2.1 MiB + 141.0 KiB =   2.2 MiB   systemd (2)
704.0 KiB +   1.7 MiB =   2.4 MiB   winbindd (4)
  1.1 MiB +   1.5 MiB =   2.6 MiB   smbd (3)
  2.5 MiB + 204.0 KiB =   2.7 MiB   udisksd
  2.5 MiB + 532.0 KiB =   3.0 MiB   ibus-ui-gtk3
  3.2 MiB + 622.0 KiB =   3.8 MiB   dbus-daemon (3)
  3.5 MiB +   1.3 MiB =   4.8 MiB   zeitgeist-fts
  4.4 MiB + 643.5 KiB =   5.0 MiB   unity-scope-home
  4.4 MiB + 704.5 KiB =   5.1 MiB   unity-settings-daemon
  4.9 MiB + 233.5 KiB =   5.1 MiB   NetworkManager
  4.8 MiB + 418.5 KiB =   5.2 MiB   gnome-software
  4.7 MiB +   1.0 MiB =   5.7 MiB   unity-files-daemon
  5.7 MiB + 280.0 KiB =   6.0 MiB   mount.ntfs (2)
  6.5 MiB +   1.1 MiB =   7.6 MiB   bamfdaemon
  6.8 MiB +   1.3 MiB =   8.2 MiB   bash (3)
  7.4 MiB + 968.0 KiB =   8.3 MiB   hud-service
  7.7 MiB +   2.4 MiB =  10.1 MiB   unity-panel-service
  9.3 MiB + 926.0 KiB =  10.2 MiB   pulseaudio
 10.6 MiB + 177.5 KiB =  10.7 MiB   fwupd
 10.6 MiB +   1.3 MiB =  11.9 MiB   unity-scope-loader
  9.7 MiB +   2.6 MiB =  12.3 MiB   gnome-terminal-server
 12.6 MiB +   2.7 MiB =  15.3 MiB   nautilus
 19.3 MiB +   2.0 MiB =  21.3 MiB   Xorg
 20.6 MiB +   4.5 MiB =  25.1 MiB   gnome-system-monitor
 23.7 MiB +   2.2 MiB =  25.9 MiB   oneconf-service
 74.9 MiB +   3.5 MiB =  78.3 MiB   compiz
465.7 MiB +   6.8 MiB = 472.5 MiB   firefox
---------------------------------
                        823.4 MiB
=================================

, но cat / proc / meminfo показывает, что только 235 172 КБ (~ 230 МБ) свободно из 8 068 136 КБ (~ 7 879) МБ).

    cat /proc/meminfo
MemTotal:        8068136 kB
MemFree:          235172 kB
MemAvailable:     929988 kB
Buffers:           67956 kB
Cached:           609744 kB
SwapCached:        47000 kB
Active:          1053864 kB
Inactive:         378708 kB
Active(anon):     720464 kB
Inactive(anon):    37844 kB
Active(file):     333400 kB
Inactive(file):   340864 kB
Unevictable:          32 kB
Mlocked:              32 kB
SwapTotal:       8279036 kB
SwapFree:        7527772 kB
Dirty:                 0 kB
Writeback:           140 kB
AnonPages:        748564 kB
Mapped:           163976 kB
Shmem:              3436 kB
Slab:             112524 kB
SReclaimable:      62840 kB
SUnreclaim:        49684 kB
KernelStack:       10880 kB
PageTables:        42012 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     9241104 kB
Committed_AS:    6502252 kB
VmallocTotal:   34359738367 kB
VmallocUsed:           0 kB
VmallocChunk:          0 kB
HardwareCorrupted:     0 kB
AnonHugePages:    106496 kB
CmaTotal:              0 kB
CmaFree:               0 kB
HugePages_Total:    3000
HugePages_Free:     3000
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:     1695128 kB
DirectMap2M:     6586368 kB

Edit1: выход бесплатный (с моим грубым переводом с немецкого на английский). Это согласуется с остальными.

              total       used     free      shared.  buffers/cached available
Memory:     8068136     7470560   209028     36916    388548      475064
Swap:       8279036      207020   8072016

Так или иначе, где-то мне не хватает 7 832 964 КБ (~ 7 649 МБ) оперативной памяти, которые используются, но нигде не перечислены ... какие-либо идеи?

Я даже не знаю, как Google эта проблема ..

Спасибо.