Nohang is a highly configurable daemon for Linux which is able to correctly prevent out of memory (OOM) and keep system responsiveness in low memory conditions.
OOM conditions may cause freezes, livelocks, drop caches and processes to be killed (via sending SIGKILL) instead of trying to terminate them correctly (via sending SIGTERM or takes other corrective action). Some applications may crash if it's impossible to allocate memory.
Here are the statements of some users:
"How do I prevent Linux from freezing when out of memory? Today I (accidentally) ran some program on my Linux box that quickly used a lot of memory. My system froze, became unresponsive and thus I was unable to kill the offender. How can I prevent this in the future? Can't it at least keep a responsive core or something running?"
— serverfault
"With or without swap it still freezes before the OOM killer gets run automatically. This is really a kernel bug that should be fixed (i.e. run OOM killer earlier, before dropping all disk cache). Unfortunately kernel developers and a lot of other folk fail to see the problem. Common suggestions such as disable/enable swap, buy more RAM, run less processes, set limits etc. do not address the underlying problem that the kernel's low memory handling sucks camel's balls."
— serverfault
Also look at Why are low memory conditions handled so badly?
- Use of earlyoom. This is a simple, stable and tiny OOM preventer written in C (the best choice for emedded and old servers). It has a minimum dependencies and can work with oldest kernels.
- Use of oomd. This is a userspace OOM killer for linux systems whitten in C++ and developed by Facebook. This is the best choice for use in large data centers. It needs Linux 4.20+.
- Use of
nohang(maybe this is a good choice for modern desktops and servers if you need fine tuning).
The tools listed above may work at the same time on one computer.
memlockdis a daemon that locks files into memory. Then if a machine starts paging heavily the chance of being able to login successfully is significantly increased.
- Sending the SIGTERM signal is default corrective action. If the victim does not respond to SIGTERM, with a further drop in the level of memory it gets SIGKILL.
- Impact on the badness of processes via matching their
- names,
- cgroup_v1,
- cgroup_v2,
- realpathes,
- environs,
- cmdlines and
- euids with specified regular expressions
- If the name of the victim matches a certain regex pattern, you can run any command instead of sending the SIGTERM signal (the default corrective action) to the victim. For example:
sysmemctl restart fookill -INT $PID(you can override the signal sent to the victim, $PID will be replaced by the victim's PID)kill -TERM $PID && script.sh(in addition to sending any signal, you can run a specified script)
- GUI notifications:
- Notification of corrective actions taken and displaying the name and PID of the victim
- Low memory warnings (displays available memory)
- zram support (
mem_used_totalas a trigger) - Initial PSI (pressure stall information) support (demo)
- Easy configuration with a
wellcommented config file
For basic usage:
Linux3.14+ (sinceMemAvailableappeared in/proc/meminfo)Python3.3+ (not tested with previous)
To show GUI notifications:
- notification server (most of desktop environments use their own implementations)
libnotify(Fedora, Arch Linux) orlibnotify-bin(Debian GNU/Linux, Ubuntu)sudoif nohang started with UID=0
To use PSI:
Linux4.20+
- VmRSS is about 10 - 12 MiB instead of the settings, about 10 MiB by default.
- CPU usage depends on the level of available memory and monitoring intensity.
Please use the latest release version. Current version may be unstable.
To download the latest stable version (v0.1):
$ wget -ct0 https://github.com/hakavlad/nohang/archive/v0.1.tar.gz
$ tar xvzf v0.1.tar.gz
$ cd nohang-0.1or to clone the latest unstable:
$ git clone https://github.com/hakavlad/nohang.git
$ cd nohangTo install:
$ sudo make installTo enable and start on systems with systemd:
$ sudo make systemdTo uninstall:
$ sudo make uninstallFor Arch Linux, there's an AUR package. Use your favorite AUR helper. For example,
$ yay -S nohang-git
$ sudo systemctl start nohang
$ sudo systemctl enable nohang./nohang -h
usage: nohang [-h] [-v] [-t] [-p] [-c CONFIG]
optional arguments:
-h, --help show this help message and exit
-v, --version print version
-t, --test print some tests
-p, --print-proc-table
print table of processes with their badness values
-c CONFIG, --config CONFIG
path to the config file, default values:
./nohang.conf, /etc/nohang/nohang.conf
The program can be configured by editing the config file. The configuration includes the following sections:
- Memory levels to respond to as an OOM threat
- Response on PSI memory metrics
- The frequency of checking the level of available memory (and CPU usage)
- The prevention of killing innocent victims
- Impact on the badness of processes via matching their names, cgroups, realpaths, cmdlines and UIDs with certain regular expressions
- The execution of a specific command or sending any signal instead of sending the SIGTERM signal
- GUI notifications:
- notifications of corrective actions taken
- low memory warnings (or executing certain command instead)
- Verbosity
- Misc
Just read the description of the parameters and edit the values. Please restart nohang to apply the changes. Default path to the config after installing is /etc/nohang/nohang.conf.
Run sudo nohang -p to see the table of prosesses with their badness values, oom_scores, names, UIDs etc.
Output example
Config: /etc/nohang/nohang.conf
###################################################################################################################
# PID PPID badness oom_score oom_score_adj eUID S VmSize VmRSS VmSwap Name CGroup
#------- ------- ------- --------- ------------- ---------- - ------ ----- ------ --------------- --------
# 336 1 1 1 0 0 S 85 25 0 systemd-journal /system.slice/systemd-journald.service
# 383 1 0 0 -1000 0 S 46 5 0 systemd-udevd /system.slice/systemd-udevd.service
# 526 2238 7 7 0 1000 S 840 96 0 kate /user.slice/user-1000.slice/session-7.scope
# 650 1 3 3 0 1000 S 760 50 0 kate /user.slice/user-1000.slice/session-7.scope
# 731 1 0 0 0 100 S 126 4 0 systemd-timesyn /system.slice/systemd-timesyncd.service
# 756 1 0 0 0 105 S 181 3 0 rtkit-daemon /system.slice/rtkit-daemon.service
# 759 1 0 0 0 0 S 277 7 0 accounts-daemon /system.slice/accounts-daemon.service
# 761 1 0 0 0 0 S 244 3 0 rsyslogd /system.slice/rsyslog.service
# 764 1 0 0 -900 108 S 45 5 0 dbus-daemon /system.slice/dbus.service
# 805 1 0 0 0 0 S 46 5 0 systemd-logind /system.slice/systemd-logind.service
# 806 1 0 0 0 0 S 35 3 0 irqbalance /system.slice/irqbalance.service
# 813 1 0 0 0 0 S 29 3 0 cron /system.slice/cron.service
# 814 1 11 11 0 0 S 176 160 0 memlockd /system.slice/memlockd.service
# 815 1 0 0 -10 0 S 32 9 0 python3 /fork.slice/fork-bomb.slice/fork-bomb-killer.slice/fork-bomb-killer.service
# 823 1 0 0 0 0 S 25 4 0 smartd /system.slice/smartd.service
# 826 1 0 0 0 113 S 46 3 0 avahi-daemon /system.slice/avahi-daemon.service
# 850 826 0 0 0 113 S 46 0 0 avahi-daemon /system.slice/avahi-daemon.service
# 868 1 0 0 0 0 S 281 8 0 polkitd /system.slice/polkit.service
# 903 1 1 1 0 0 S 4094 16 0 stunnel4 /system.slice/stunnel4.service
# 940 1 0 0 -600 0 S 39 10 0 python3 /nohang.slice/nohang.service
# 1014 1 0 0 0 13 S 22 2 0 obfs-local /system.slice/obfs-local.service
# 1015 1 0 0 0 1000 S 36 4 0 ss-local /system.slice/ss-local.service
# 1023 1 0 0 0 116 S 33 2 0 dnscrypt-proxy /system.slice/dnscrypt-proxy.service
# 1029 1 1 1 0 119 S 4236 16 0 privoxy /system.slice/privoxy.service
# 1035 1 0 0 0 0 S 355 6 0 lightdm /system.slice/lightdm.service
# 1066 1 0 0 0 0 S 45 7 0 wpa_supplicant /system.slice/wpa_supplicant.service
# 1178 1 0 0 0 0 S 14 2 0 agetty /system.slice/system-getty.slice/[email protected]
# 1294 1 0 0 -1000 0 S 4 1 0 watchdog /system.slice/watchdog.service
# 1632 1 1 1 0 1000 S 1391 22 0 pulseaudio /user.slice/user-1000.slice/session-2.scope
# 1689 1632 0 0 0 1000 S 125 5 0 gconf-helper /user.slice/user-1000.slice/session-2.scope
# 1711 1 0 0 0 0 S 367 8 0 udisksd /system.slice/udisks2.service
# 1819 1 0 0 0 0 S 304 8 0 upowerd /system.slice/upower.service
# 1879 1 0 0 0 1000 S 64 7 0 systemd /user.slice/user-1000.slice/[email protected]/init.scope
# 1880 1879 0 0 0 1000 S 229 2 0 (sd-pam) /user.slice/user-1000.slice/[email protected]/init.scope
# 1888 1 0 0 0 0 S 14 2 0 agetty /system.slice/system-getty.slice/[email protected]
# 1889 1 0 0 0 0 S 14 2 0 agetty /system.slice/system-getty.slice/[email protected]
# 1890 1 0 0 0 0 S 14 2 0 agetty /system.slice/system-getty.slice/[email protected]
# 1891 1 0 0 0 0 S 14 2 0 agetty /system.slice/system-getty.slice/[email protected]
# 1892 1 0 0 0 0 S 14 2 0 agetty /system.slice/system-getty.slice/[email protected]
# 1893 1035 14 14 0 0 R 623 208 0 Xorg /system.slice/lightdm.service
# 1904 1 0 0 0 111 S 64 7 0 systemd /user.slice/user-111.slice/[email protected]/init.scope
# 1905 1904 0 0 0 111 S 229 2 0 (sd-pam) /user.slice/user-111.slice/[email protected]/init.scope
# 1916 1904 0 0 0 111 S 44 3 0 dbus-daemon /user.slice/user-111.slice/[email protected]/dbus.service
# 1920 1 0 0 0 111 S 215 5 0 at-spi2-registr /user.slice/user-111.slice/session-c2.scope
# 1922 1904 0 0 0 111 S 278 6 0 gvfsd /user.slice/user-111.slice/[email protected]/gvfs-daemon.service
# 1935 1035 0 0 0 0 S 238 6 0 lightdm /user.slice/user-1000.slice/session-7.scope
# 1942 1 0 0 0 1000 S 210 9 0 gnome-keyring-d /user.slice/user-1000.slice/session-7.scope
# 1944 1935 1 1 0 1000 S 411 21 0 mate-session /user.slice/user-1000.slice/session-7.scope
# 1952 1879 0 0 0 1000 S 45 5 0 dbus-daemon /user.slice/user-1000.slice/[email protected]/dbus.service
# 1981 1944 0 0 0 1000 S 11 0 0 ssh-agent /user.slice/user-1000.slice/session-7.scope
# 1984 1879 0 0 0 1000 S 278 6 0 gvfsd /user.slice/user-1000.slice/[email protected]/gvfs-daemon.service
# 1990 1879 0 0 0 1000 S 341 5 0 at-spi-bus-laun /user.slice/user-1000.slice/[email protected]/at-spi-dbus-bus.service
# 1995 1990 0 0 0 1000 S 44 4 0 dbus-daemon /user.slice/user-1000.slice/[email protected]/at-spi-dbus-bus.service
# 1997 1879 0 0 0 1000 S 215 5 0 at-spi2-registr /user.slice/user-1000.slice/[email protected]/at-spi-dbus-bus.service
# 2000 1879 0 0 0 1000 S 184 5 0 dconf-service /user.slice/user-1000.slice/[email protected]/dbus.service
# 2009 1944 2 2 0 1000 S 1308 35 0 mate-settings-d /user.slice/user-1000.slice/session-7.scope
# 2013 1944 2 2 0 1000 S 436 32 0 marco /user.slice/user-1000.slice/session-7.scope
# 2024 1944 4 4 0 1000 S 1258 55 0 caja /user.slice/user-1000.slice/session-7.scope
# 2032 1 1 1 0 1000 S 333 18 0 msd-locate-poin /user.slice/user-1000.slice/session-7.scope
# 2033 1879 0 0 0 1000 S 348 11 0 gvfs-udisks2-vo /user.slice/user-1000.slice/[email protected]/gvfs-udisks2-volume-monitor.service
# 2036 1944 1 1 0 1000 S 331 17 0 polkit-mate-aut /user.slice/user-1000.slice/session-7.scope
# 2038 1944 5 5 0 1000 S 682 78 0 mate-panel /user.slice/user-1000.slice/session-7.scope
# 2041 1944 2 2 0 1000 S 514 31 0 nm-applet /user.slice/user-1000.slice/session-7.scope
# 2046 1944 1 1 0 1000 S 495 25 0 mate-power-mana /user.slice/user-1000.slice/session-7.scope
# 2047 1944 2 2 0 1000 S 692 32 0 mate-volume-con /user.slice/user-1000.slice/session-7.scope
# 2049 1944 3 3 0 1000 S 548 44 0 mate-screensave /user.slice/user-1000.slice/session-7.scope
# 2059 1879 0 0 0 1000 S 263 5 0 gvfs-goa-volume /user.slice/user-1000.slice/[email protected]/gvfs-goa-volume-monitor.service
# 2076 1879 0 0 0 1000 S 352 7 0 gvfsd-trash /user.slice/user-1000.slice/[email protected]/gvfs-daemon.service
# 2077 1879 0 0 0 1000 S 362 7 0 gvfs-afc-volume /user.slice/user-1000.slice/[email protected]/gvfs-afc-volume-monitor.service
# 2087 1879 0 0 0 1000 S 263 5 0 gvfs-mtp-volume /user.slice/user-1000.slice/[email protected]/gvfs-mtp-volume-monitor.service
# 2093 1879 0 0 0 1000 S 275 6 0 gvfs-gphoto2-vo /user.slice/user-1000.slice/[email protected]/gvfs-gphoto2-volume-monitor.service
# 2106 1879 3 3 0 1000 S 544 42 0 wnck-applet /user.slice/user-1000.slice/[email protected]/dbus.service
# 2108 1879 1 1 0 1000 S 396 21 0 notification-ar /user.slice/user-1000.slice/[email protected]/dbus.service
# 2112 1879 1 1 0 1000 S 499 25 0 mate-sensors-ap /user.slice/user-1000.slice/[email protected]/dbus.service
# 2113 1879 1 1 0 1000 S 390 21 0 mate-brightness /user.slice/user-1000.slice/[email protected]/dbus.service
# 2114 1879 1 1 0 1000 S 534 22 0 mate-multiload- /user.slice/user-1000.slice/[email protected]/dbus.service
# 2118 1879 2 2 0 1000 S 547 29 0 clock-applet /user.slice/user-1000.slice/[email protected]/dbus.service
# 2152 1879 1 1 0 1000 S 218 22 0 gvfsd-metadata /user.slice/user-1000.slice/[email protected]/gvfs-metadata.service
# 2206 1 3 3 0 110 S 106 48 0 tor /system.slice/system-tor.slice/[email protected]
# 2229 1 3 3 0 1000 S 999 42 0 kactivitymanage /user.slice/user-1000.slice/session-7.scope
# 2238 1 0 0 0 1000 S 150 9 0 kdeinit5 /user.slice/user-1000.slice/session-7.scope
# 2239 2238 3 3 0 1000 S 648 41 0 klauncher /user.slice/user-1000.slice/session-7.scope
# 3959 1 1 1 0 0 S 615 18 0 NetworkManager /system.slice/NetworkManager.service
# 3977 3959 0 0 0 0 S 20 4 0 dhclient /system.slice/NetworkManager.service
# 5626 1879 0 0 0 1000 S 355 7 0 gvfsd-network /user.slice/user-1000.slice/[email protected]/gvfs-daemon.service
# 5637 1879 1 1 0 1000 S 623 14 0 gvfsd-smb-brows /user.slice/user-1000.slice/[email protected]/gvfs-daemon.service
# 6296 1879 0 0 0 1000 S 435 7 0 gvfsd-dnssd /user.slice/user-1000.slice/[email protected]/gvfs-daemon.service
# 11129 1879 3 3 0 1000 S 597 42 0 kded5 /user.slice/user-1000.slice/[email protected]/dbus.service
# 11136 1879 2 2 0 1000 S 639 39 0 kuiserver5 /user.slice/user-1000.slice/[email protected]/dbus.service
# 11703 1879 3 3 0 1000 S 500 45 0 mate-system-mon /user.slice/user-1000.slice/[email protected]/dbus.service
# 16798 1879 0 0 0 1000 S 346 10 0 gvfsd-http /user.slice/user-1000.slice/[email protected]/gvfs-daemon.service
# 18133 1 3 3 0 1000 S 760 49 0 kate /user.slice/user-1000.slice/session-7.scope
# 18144 2038 1 1 0 1000 S 301 23 0 lxterminal /user.slice/user-1000.slice/session-7.scope
# 18147 18144 0 0 0 1000 S 14 2 0 gnome-pty-helpe /user.slice/user-1000.slice/session-7.scope
# 18148 18144 1 1 0 1000 S 42 26 0 bash /user.slice/user-1000.slice/session-7.scope
# 18242 2238 1 1 0 1000 S 194 14 0 file.so /user.slice/user-1000.slice/session-7.scope
# 18246 18148 0 0 0 0 S 54 4 0 sudo /user.slice/user-1000.slice/session-7.scope
# 19003 1 0 0 0 0 S 310 12 0 packagekitd /system.slice/packagekit.service
# 26993 2038 91 91 0 1000 S 3935 1256 0 firefox-esr /user.slice/user-1000.slice/session-7.scope
# 27275 26993 121 121 0 1000 S 3957 1684 0 Web Content /user.slice/user-1000.slice/session-7.scope
# 30374 1 1 1 0 1000 S 167 14 0 VBoxXPCOMIPCD /user.slice/user-1000.slice/session-7.scope
# 30380 1 2 2 0 1000 S 958 27 0 VBoxSVC /user.slice/user-1000.slice/session-7.scope
# 30549 30380 86 86 0 1000 S 5332 1192 0 VirtualBox /user.slice/user-1000.slice/session-7.scope
# 30875 1 1 1 0 1000 S 345 26 0 leafpad /user.slice/user-1000.slice/session-7.scope
# 32689 1 7 7 0 1000 S 896 99 0 dolphin /user.slice/user-1000.slice/session-7.scope
###################################################################################################################
Process with highest badness (found in 55 ms):
PID: 27275, Name: Web Content, badness: 121
oom-sort is an additional diagnostic tool that will be installed with nohang package. It sorts the processes in descending order of their oom_score and also displays oom_score_adj, Uid, Pid, Name, VmRSS, VmSwap and optionally cmdline. Run oom-sort --help for more info.
Usage:
$ oom-sort
Output example
oom_score oom_score_adj UID PID Name VmRSS VmSwap cmdline
--------- ------------- ---- ----- --------------- ------- -------- -------
23 0 0 964 Xorg 58 M 22 M /usr/libexec/Xorg -background none :0 vt01 -nolisten tcp -novtswitch -auth /var/run/lxdm/lxdm-:0.auth
13 0 1000 1365 pcmanfm 38 M 10 M pcmanfm --desktop --profile LXDE
10 0 1000 1408 dnfdragora-upda 9 M 27 M /usr/bin/python3 /bin/dnfdragora-updater
5 0 0 822 firewalld 0 M 19 M /usr/bin/python3 /usr/sbin/firewalld --nofork --nopid
5 0 1000 1364 lxpanel 18 M 2 M lxpanel --profile LXDE
5 0 1000 1685 nm-applet 6 M 12 M nm-applet
5 0 1000 1862 lxterminal 16 M 2 M lxterminal
4 0 996 890 polkitd 8 M 6 M /usr/lib/polkit-1/polkitd --no-debug
4 0 1000 1703 pnmixer 6 M 11 M pnmixer
3 0 0 649 systemd-journal 10 M 1 M /usr/lib/systemd/systemd-journald
3 0 1000 1360 openbox 9 M 2 M openbox --config-file /home/user/.config/openbox/lxde-rc.xml
3 0 1000 1363 notification-da 3 M 10 M /usr/libexec/notification-daemon
2 0 1000 1744 clipit 5 M 3 M clipit
2 0 1000 2619 python3 9 M 0 M python3 /bin/oom-sort
1 0 0 809 rsyslogd 3 M 3 M /usr/sbin/rsyslogd -n
1 0 0 825 udisksd 2 M 2 M /usr/libexec/udisks2/udisksd
1 0 0 873 sssd_nss 4 M 1 M /usr/libexec/sssd/sssd_nss --uid 0 --gid 0 --logger=files
1 0 0 876 systemd-logind 2 M 2 M /usr/lib/systemd/systemd-logind
1 0 0 907 abrt-dump-journ 2 M 1 M /usr/bin/abrt-dump-journal-oops -fxtD
1 0 0 920 NetworkManager 3 M 2 M /usr/sbin/NetworkManager --no-daemon
1 0 1000 1115 systemd 4 M 1 M /usr/lib/systemd/systemd --user
1 0 1000 1118 (sd-pam) 0 M 5 M (sd-pam)
1 0 1000 1366 xscreensaver 5 M 0 M xscreensaver -no-splash
1 0 1000 1851 gvfsd-trash 3 M 1 M /usr/libexec/gvfsd-trash --spawner :1.6 /org/gtk/gvfs/exec_spaw/0
1 0 1000 1969 gvfsd-metadata 6 M 0 M /usr/libexec/gvfsd-metadata
1 0 1000 2262 bash 5 M 0 M bash
0 -1000 0 675 systemd-udevd 0 M 4 M /usr/lib/systemd/systemd-udevd
0 -1000 0 787 auditd 0 M 1 M /sbin/auditd
0 0 0 807 ModemManager 0 M 1 M /usr/sbin/ModemManager
0 0 0 808 smartd 0 M 1 M /usr/sbin/smartd -n -q never
0 0 0 810 alsactl 0 M 0 M /usr/sbin/alsactl -s -n 19 -c -E ALSA_CONFIG_PATH=/etc/alsa/alsactl.conf --initfile=/lib/alsa/init/00main rdaemon
0 0 0 811 mcelog 0 M 0 M /usr/sbin/mcelog --ignorenodev --daemon --foreground
0 0 172 813 rtkit-daemon 0 M 0 M /usr/libexec/rtkit-daemon
0 0 0 814 VBoxService 0 M 1 M /usr/sbin/VBoxService -f
0 0 0 817 rngd 0 M 1 M /sbin/rngd -f
0 -900 81 818 dbus-daemon 3 M 0 M /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
0 0 0 823 irqbalance 0 M 0 M /usr/sbin/irqbalance --foreground
0 0 70 824 avahi-daemon 0 M 0 M avahi-daemon: running [linux.local]
0 0 0 826 sssd 0 M 2 M /usr/sbin/sssd -i --logger=files
0 0 995 838 chronyd 1 M 0 M /usr/sbin/chronyd
0 0 0 849 gssproxy 0 M 1 M /usr/sbin/gssproxy -D
0 0 0 866 abrtd 0 M 2 M /usr/sbin/abrtd -d -s
0 0 70 870 avahi-daemon 0 M 0 M avahi-daemon: chroot helper
0 0 0 871 sssd_be 0 M 2 M /usr/libexec/sssd/sssd_be --domain implicit_files --uid 0 --gid 0 --logger=files
0 0 0 875 accounts-daemon 0 M 1 M /usr/libexec/accounts-daemon
0 0 0 906 abrt-dump-journ 1 M 2 M /usr/bin/abrt-dump-journal-core -D -T -f -e
0 0 0 908 abrt-dump-journ 1 M 2 M /usr/bin/abrt-dump-journal-xorg -fxtD
0 0 0 950 crond 2 M 1 M /usr/sbin/crond -n
0 0 0 951 atd 0 M 0 M /usr/sbin/atd -f
0 0 0 953 lxdm-binary 0 M 0 M /usr/sbin/lxdm-binary
0 0 0 1060 dhclient 0 M 2 M /sbin/dhclient -d -q -sf /usr/libexec/nm-dhcp-helper -pf /var/run/dhclient-enp0s3.pid -lf /var/lib/NetworkManager/dhclient-939eab05-4796-3792-af24-9f76cf53ca7f-enp0s3.lease -cf /var/lib/NetworkManager/dhclient-enp0s3.conf enp0s3
0 0 0 1105 lxdm-session 0 M 1 M /usr/libexec/lxdm-session
0 0 1000 1123 pulseaudio 0 M 3 M /usr/bin/pulseaudio --daemonize=no
0 0 1000 1124 lxsession 1 M 2 M /usr/bin/lxsession -s LXDE -e LXDE
0 0 1000 1134 dbus-daemon 2 M 0 M /usr/bin/dbus-daemon --session --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only
0 0 1000 1215 imsettings-daem 0 M 1 M /usr/libexec/imsettings-daemon
0 0 1000 1218 gvfsd 3 M 1 M /usr/libexec/gvfsd
0 0 1000 1223 gvfsd-fuse 0 M 1 M /usr/libexec/gvfsd-fuse /run/user/1000/gvfs -f -o big_writes
0 0 1000 1309 VBoxClient 0 M 0 M /usr/bin/VBoxClient --display
0 0 1000 1310 VBoxClient 0 M 0 M /usr/bin/VBoxClient --clipboard
0 0 1000 1311 VBoxClient 0 M 0 M /usr/bin/VBoxClient --draganddrop
0 0 1000 1312 VBoxClient 0 M 0 M /usr/bin/VBoxClient --display
0 0 1000 1313 VBoxClient 1 M 0 M /usr/bin/VBoxClient --clipboard
0 0 1000 1316 VBoxClient 0 M 0 M /usr/bin/VBoxClient --seamless
0 0 1000 1318 VBoxClient 0 M 0 M /usr/bin/VBoxClient --seamless
0 0 1000 1320 VBoxClient 0 M 0 M /usr/bin/VBoxClient --draganddrop
0 0 1000 1334 ssh-agent 0 M 0 M /usr/bin/ssh-agent /bin/sh -c exec -l bash -c "/usr/bin/startlxde"
0 0 1000 1362 lxpolkit 0 M 1 M lxpolkit
0 0 1000 1370 lxclipboard 0 M 1 M lxclipboard
0 0 1000 1373 ssh-agent 0 M 1 M /usr/bin/ssh-agent -s
0 0 1000 1485 agent 0 M 1 M /usr/libexec/geoclue-2.0/demos/agent
0 0 1000 1751 menu-cached 0 M 1 M /usr/libexec/menu-cache/menu-cached /run/user/1000/menu-cached-:0
0 0 1000 1780 at-spi-bus-laun 0 M 1 M /usr/libexec/at-spi-bus-launcher
0 0 1000 1786 dbus-daemon 1 M 0 M /usr/bin/dbus-daemon --config-file=/usr/share/defaults/at-spi2/accessibility.conf --nofork --print-address 3
0 0 1000 1792 at-spi2-registr 1 M 1 M /usr/libexec/at-spi2-registryd --use-gnome-session
0 0 1000 1840 gvfs-udisks2-vo 0 M 2 M /usr/libexec/gvfs-udisks2-volume-monitor
0 0 1000 1863 gnome-pty-helpe 1 M 0 M gnome-pty-helper
0 0 1000 1864 bash 0 M 1 M bash
0 0 0 1899 sudo 0 M 1 M sudo -i
0 0 0 1901 bash 0 M 1 M -bash
0 0 0 1953 oomd_bin 0 M 0 M oomd_bin -f /sys/fs/cgroup/unified
0 -600 0 2562 python3 10 M 0 M python3 /usr/sbin/nohang --config /etc/nohang/nohang.conf
Kthreads, zombies and Pid 1 will not be displayed.
To view the latest entries in the log (for systemd users):
$ sudo journalctl -eu nohangSee also man journalctl.
You can also enable separate_log in the config to logging in /var/log/nohang/nohang.log.
- Awful documentation
- Non-optimal default settings (I do not know which settings are optimal for most users; you need a configuration for better experience)
- No installation option for non-systemd users
- No deb/rpm packages
Please create issues. Use cases, feature requests and any questions are welcome.
-
In progress
- Added new CLI options:
- -v, --version
- -t, --test
- -p, --print-proc-table
- Possible process crashes are fixed:
- Fixed crash at startup due to
UnicodeDecodeErroron some systems - Handled
UnicodeDecodeErrorif victim name consists of many unicode characters (rfjakob/earlyoom#110) - Fixed process crash before performing corrective actions if Python 3.4 or lower are used to interpret nohang
- Fixed crash at startup due to
- Improve output:
- Display
oom_score,oom_score_adj,Ancestry,EUID,State,VmSize,RssAnon,RssFile,RssShmem,CGroup_v1,CGroup_v2,Realpath,CmdlineandLifetimeof the victim in corrective action reports - Added memory report interval
- Added delta memory info (the rate of change of available memory)
- Print statistics on corrective actions after each corrective action
- Added ability to print a process table before each corrective action
- Added the ability to log into a separate file
- Display
- Improved GUI warnings:
- Reduced the idle time of the daemon in the process of launching a notification
- All notify-send calls are made using the
nohang_notify_helperscript, in which all timeouts are handled - Native python implementation of
envsearch without runningpsto notify all users if nohang started with UID=0. - Messages are sent to the helper via a temporary file in
/dev/shm - Deduplication of frequently repeated identical notifications (for example, if the victim does not respond to SIGTERM)
- Improved modifing badness via matching with regular expressions:
- Added the ability to set many different
badness_adjfor processes depending on the matchingName,CGroup,cmdline,realpathandEUIDwith the specified regular expressions (issue #74) - Fix: replace
re.fullmatch()byre.search()
- Added the ability to set many different
- Reduced memory usage:
- Reduced memory usage and startup time (using
sys.argvinstead ofargparse) - Reduced memory usage with
mlockall()usingMCL_ONFAULT(rfjakob/earlyoom#112) and lock all memory by default
- Reduced memory usage and startup time (using
- Improve poll rate algorithm
- Fixed Makefile for installation on CentOS 7 (remove gzip
-koption). - Added
max_post_sigterm_victim_lifetimeoption: send SIGKILL to the victim if it doesn't respond to SIGTERM for a certain time - Added
post_kill_exeoption (the ability to run any command after killing the victim) - Added
warning_exeoption (the ability to run any command instead of GUI low memory warnings) - Improved victim search algorithm (do it ~30% faster) (rfjakob/earlyoom#114)
- Improved limiting
oom_score_adj: now it can works with UID != 0 - Fixed conf parsing: use of
line.partition('=')instead ofline.split('=') - Added
oom-sort - Removed self-defense options from the config, use systemd unit scheduling instead
- Added the ability to send any signal instead of SIGTERM for processes with certain names
- Added initial support for
PSI - Improved user input validation
- Improved documentation
- Added new CLI options:
-
v0.1, 2018-11-23: Initial release