![pic](https://i.imgur.com/scXQ312.png)
nohang
![Packaging status](https://repology.org/badge/tiny-repos/nohang.svg)
nohang
package provides a highly configurable daemon for Linux which is able to correctly prevent out of memory (OOM) and keep system responsiveness in low memory conditions.
The package also includes additional diagnostic tools (oom-sort
, psi2log
, psi-top
).
What is the problem?
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
"The traditional Linux OOM killer works fine in some cases, but in others it kicks in too late, resulting in the system entering a livelock for an indeterminate period."
— engineering.fb.com
Also look at these discussions:
Solution
Use one of the userspace OOM killers:
- earlyoom: This is a simple, stable and tiny OOM prevention daemon written in C (the best choice for emedded and old servers). It has a minimum dependencies and can work with oldest kernels. It is enabled by default on Fedora 32 Workstation (and F33 KDE).
- oomd: This is a userspace OOM killer for linux systems written in C++ and developed by Facebook. This is the best choice for use in large data centers. It needs Linux 4.20+.
- systemd-oomd: Provided by systemd as
systemd-oomd.service
that uses cgroups-v2 and pressure stall information (PSI) to monitor and take action on processes before an OOM occurs in kernel space. It's used by default on desktop versions of Fedora 34.
- low-memory-monitor: There's a project announcement.
- psi-monitor: It's used by default on Endless OS.
nohang
: nohang is earlyoom on steroids and has many useful features, see below. Maybe this is a good choice for modern desktops and servers if you need fine-tuning. Previously it was used by default on Garuda Linux.
Use these tools to improve responsiveness during heavy swapping:
- MGLRU patchset is merged in Linux 6.1. Setting
min_ttl_ms
> 50 can help you.
- le9-patch: [PATCH] mm: Protect clean file pages under memory pressure to prevent thrashing, avoid high latency and prevent livelock in near-OOM conditions. It's kernel-side solution that can fix the OOM killer behavior.
- prelockd: Lock executables and shared libraries in memory to improve system responsiveness under low-memory conditions.
- memavaild: Keep amount of available memory by evicting memory of selected cgroups into swap space.
- uresourced: This daemon will give resource allocations to active graphical users. It's enabled by default on Fedora 33 Workstation.
Of course, you can also download more RAM, tune virtual memory, use zram/zswap and use limits for cgroups.
Features
- 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;
- Customizing victim selection: impact on the badness of processes via matching their names, cgroups, exe realpathes, environs, cmdlines and euids with specified regular expressions;
- Customizing corrective actions: if the name or control group 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:
systemctl restart foo
;
kill -INT $PID
(you can override the signal sent to the victim, $PID will be replaced by the victim's PID).
- GUI notifications:
- Notification of corrective actions taken and displaying the name and PID of the victim;
- Low memory warnings.
- zram support (
mem_used_total
as a trigger);
- PSI (pressure stall information) support;
- Optional checking kernel messages for OOM events;
- Easy setup with configuration files (nohang.conf, nohang-desktop.conf).
Demo
nohang
prevents Out Of Memory with GUI notifications:
Requirements
For basic usage:
Linux
(>= 3.14, since MemAvailable
appeared in /proc/meminfo
)
Python
(>= 3.3)
To respond to PSI
metrics (optional):
Linux
(>= 4.20) with CONFIG_PSI=y
To show GUI notifications (optional):
- notification server (most of desktop environments use their own implementations)
libnotify
(Arch Linux, Fedora, openSUSE) or libnotify-bin
(Debian GNU/Linux, Ubuntu)
sudo
if nohang started with UID=0.
Memory and CPU usage
- VmRSS is about 10–14 MiB instead of the settings, about 10–11 MiB by default (with Python <= 3.8), about 16–17 MiB with Python 3.9.
- CPU usage depends on the level of available memory and monitoring intensity.
Warnings
- the daemon runs with super-user privileges and has full access to all private memory of all processes and sensitive user data;
- the daemon does not forbid you to shoot yourself in the foot: with some settings, unwanted killings of processes can occur;
- the daemon is not a panacea: there are no universal settings that reliably protect against all types of threats.
Known problems
nohang vs nohang-desktop
nohang
comes with two configs: nohang.conf
and nohang-desktop.conf
. nohang
comes with two systemd service unit files: nohang.service
and nohang-desktop.service
. Choose one.
nohang.conf
provides vanilla default settings without PSI checking enabled, without any badness correction and without GUI notifications enabled.
nohang-desktop.conf
provides default settings optimized for desktop usage.
How to install
To install on Fedora:
Orphaned for 6+ weeks, not available.
To install on RHEL 7 and RHEL 8:
nohang is avaliable in EPEL repos.
sudo yum install nohang
sudo systemctl enable nohang.service
sudo systemctl start nohang.service
To enable PSI on RHEL 8 pass psi=1
to kernel boot cmdline.
For Arch Linux there's an AUR package
Use your favorite AUR helper. For example,
yay -S nohang-git
sudo systemctl enable --now nohang-desktop.service
To install on Ubuntu 20.04/20.10
To install from PPA:
sudo add-apt-repository ppa:oibaf/test
sudo apt update
sudo apt install nohang
sudo systemctl enable --now nohang-desktop.service
To install on Debian and Ubuntu-based systems:
Outdated and buggy nohang v0.1 release was packaged for Debian 11 and Ubuntu 20.10.
It's easy to build a deb package with the latest git snapshot. Install build dependencies:
sudo apt install make fakeroot
Clone the latest git snapshot and run the build script to build the package:
git clone https://github.com/hakavlad/nohang.git && cd nohang
deb/build.sh
Install the package:
sudo apt install --reinstall ./deb/package.deb
Start and enable nohang.service
or nohang-desktop.service
after installing the package:
sudo systemctl enable --now nohang-desktop.service
To install on Gentoo and derivatives (e.g. Funtoo):
Add the eph kit overlay, for example using layman or as a local repository.
Then update your repos:
sudo layman -S # if added via layman
sudo emerge --sync # local repo on Gentoo
sudo ego sync # local repo on Funtoo
Install:
sudo emerge -a nohang
Start the service:
sudo rc-service nohang-desktop start
Optionally add to startup:
sudo rc-update add nohang-desktop default
To install the latest version on any distro:
git clone https://github.com/hakavlad/nohang.git && cd nohang
sudo make install
Config files will be located in /usr/local/etc/nohang/
. To enable and start unit without GUI notifications:
sudo systemctl enable --now nohang.service
To enable and start unit with GUI notifications:
sudo systemctl enable --now nohang-desktop.service
On systems with OpenRC:
sudo make install-openrc
To uninstall:
sudo make uninstall
Command line options
./nohang -h
usage: nohang [-h|--help] [-v|--version] [-m|--memload]
[-c|--config CONFIG] [--check] [--monitor] [--tasks]
optional arguments:
-h, --help show this help message and exit
-v, --version show version of installed package and exit
-m, --memload consume memory until 40 MiB (MemAvailable + SwapFree)
remain free, and terminate the process
-c CONFIG, --config CONFIG
path to the config file. This should only be used
with one of the following options:
--monitor, --tasks, --check
--check check and show the configuration and exit. This should
only be used with -c/--config CONFIG option
--monitor start monitoring. This should only be used with
-c/--config CONFIG option
--tasks show tasks state and exit. This should only be used
with -c/--config CONFIG option
How to configure
The program can be configured by editing the config file. The configuration includes the following sections:
- Checking kernel messages for OOM events;
- Common zram settings;
- Common PSI settings;
- Poll rate;
- Warnings and notifications;
- Soft threshold;
- Hard threshold;
- Customize victim selection;
- Customize soft corrective actions;
- Misc settings;
- Verbosity, debug, logging.
Just read the description of the parameters and edit the values. Please restart the daemon to apply the changes.
How to test nohang
- The safest way is to run
nohang --memload
. This causes memory consumption, and the process will exits before OOM occurs.
- Another way is to run
tail /dev/zero
. This causes fast memory comsumption and causes OOM at the end.
If testing occurs while nohang
is running, these processes should be terminated before OOM occurs.
Tasks state
Run sudo nohang -c/--config CONFIG --tasks
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/getty@tty1.service
# 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/user@1000.service/init.scope
# 1880 1879 0 0 0 1000 S 229 2 0 (sd-pam) /user.slice/user-1000.slice/user@1000.service/init.scope
# 1888 1 0 0 0 0 S 14 2 0 agetty /system.slice/system-getty.slice/getty@tty2.service
# 1889 1 0 0 0 0 S 14 2 0 agetty /system.slice/system-getty.slice/getty@tty3.service
# 1890 1 0 0 0 0 S 14 2 0 agetty /system.slice/system-getty.slice/getty@tty4.service
# 1891 1 0 0 0 0 S 14 2 0 agetty /system.slice/system-getty.slice/getty@tty5.service
# 1892 1 0 0 0 0 S 14 2 0 agetty /system.slice/system-getty.slice/getty@tty6.service
# 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/user@111.service/init.scope
# 1905 1904 0 0 0 111 S 229 2 0 (sd-pam) /user.slice/user-111.slice/user@111.service/init.scope
# 1916 1904 0 0 0 111 S 44 3 0 dbus-daemon /user.slice/user-111.slice/user@111.service/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/user@111.service/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/user@1000.service/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/user@1000.service/gvfs-daemon.service
# 1990 1879 0 0 0 1000 S 341 5 0 at-spi-bus-laun /user.slice/user-1000.slice/user@1000.service/at-spi-dbus-bus.service
# 1995 1990 0 0 0 1000 S 44 4 0 dbus-daemon /user.slice/user-1000.slice/user@1000.service/at-spi-dbus-bus.service
# 1997 1879 0 0 0 1000 S 215 5 0 at-spi2-registr /user.slice/user-1000.slice/user@1000.service/at-spi-dbus-bus.service
# 2000 1879 0 0 0 1000 S 184 5 0 dconf-service /user.slice/user-1000.slice/user@1000.service/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/user@1000.service/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/user@1000.service/gvfs-goa-volume-monitor.service
# 2076 1879 0 0 0 1000 S 352 7 0 gvfsd-trash /user.slice/user-1000.slice/user@1000.service/gvfs-daemon.service
# 2077 1879 0 0 0 1000 S 362 7 0 gvfs-afc-volume /user.slice/user-1000.slice/user@1000.service/gvfs-afc-volume-monitor.service
# 2087 1879 0 0 0 1000 S 263 5 0 gvfs-mtp-volume /user.slice/user-1000.slice/user@1000.service/gvfs-mtp-volume-monitor.service
# 2093 1879 0 0 0 1000 S 275 6 0 gvfs-gphoto2-vo /user.slice/user-1000.slice/user@1000.service/gvfs-gphoto2-volume-monitor.service
# 2106 1879 3 3 0 1000 S 544 42 0 wnck-applet /user.slice/user-1000.slice/user@1000.service/dbus.service
# 2108 1879 1 1 0 1000 S 396 21 0 notification-ar /user.slice/user-1000.slice/user@1000.service/dbus.service
# 2112 1879 1 1 0 1000 S 499 25 0 mate-sensors-ap /user.slice/user-1000.slice/user@1000.service/dbus.service
# 2113 1879 1 1 0 1000 S 390 21 0 mate-brightness /user.slice/user-1000.slice/user@1000.service/dbus.service
# 2114 1879 1 1 0 1000 S 534 22 0 mate-multiload- /user.slice/user-1000.slice/user@1000.service/dbus.service
# 2118 1879 2 2 0 1000 S 547 29 0 clock-applet /user.slice/user-1000.slice/user@1000.service/dbus.service
# 2152 1879 1 1 0 1000 S 218 22 0 gvfsd-metadata /user.slice/user-1000.slice/user@1000.service/gvfs-metadata.service
# 2206 1 3 3 0 110 S 106 48 0 tor /system.slice/system-tor.slice/tor@default.service
# 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/user@1000.service/gvfs-daemon.service
# 5637 1879 1 1 0 1000 S 623 14 0 gvfsd-smb-brows /user.slice/user-1000.slice/user@1000.service/gvfs-daemon.service
# 6296 1879 0 0 0 1000 S 435 7 0 gvfsd-dnssd /user.slice/user-1000.slice/user@1000.service/gvfs-daemon.service
# 11129 1879 3 3 0 1000 S 597 42 0 kded5 /user.slice/user-1000.slice/user@1000.service/dbus.service
# 11136 1879 2 2 0 1000 S 639 39 0 kuiserver5 /user.slice/user-1000.slice/user@1000.service/dbus.service
# 11703 1879 3 3 0 1000 S 500 45 0 mate-system-mon /user.slice/user-1000.slice/user@1000.service/dbus.service
# 16798 1879 0 0 0 1000 S 346 10 0 gvfsd-http /user.slice/user-1000.slice/user@1000.service/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
```
Logging
To view the latest entries in the log (for systemd users):
sudo journalctl -eu nohang.service
#### or
sudo journalctl -eu nohang-desktop.service
You can also enable separate_log
in the config to logging in /var/log/nohang/nohang.log
.
oom-sort
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. Man page: oom-sort.manpage.md.
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.
psi-top
psi-top is script that prints the PSI metrics values for every cgroup. It requires Linux
>= 4.20 with CONFIG_PSI=y
. Man page: psi-top.manpage.md.
Output example
```
$ psi-top
cgroup2 mountpoint: /sys/fs/cgroup
avg10 avg60 avg300 avg10 avg60 avg300 cgroup2
----- ----- ------ ----- ----- ------ ---------
some 0.00 0.21 1.56 | full 0.00 0.16 1.14 [SYSTEM_WIDE]
some 0.00 0.21 1.56 | full 0.00 0.16 1.14
some 0.00 0.15 1.11 | full 0.00 0.12 0.89 /user.slice
some 45.92 28.77 20.19 | full 45.05 28.17 19.56 /user.slice/user-1000.slice
some 1.44 4.67 9.24 | full 1.44 4.65 9.20 /user.slice/user-1000.slice/user@1000.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /user.slice/user-1000.slice/user@1000.service/pulseaudio.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /user.slice/user-1000.slice/user@1000.service/gvfs-daemon.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /user.slice/user-1000.slice/user@1000.service/dbus.socket
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /user.slice/user-1000.slice/user@1000.service/gvfs-udisks2-volume-monitor.service
some 0.25 1.97 4.05 | full 0.25 1.96 4.03 /user.slice/user-1000.slice/user@1000.service/xfce4-notifyd.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /user.slice/user-1000.slice/user@1000.service/init.scope
some 0.00 0.66 1.99 | full 0.00 0.66 1.97 /user.slice/user-1000.slice/user@1000.service/gpg-agent.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /user.slice/user-1000.slice/user@1000.service/gvfs-gphoto2-volume-monitor.service
some 0.93 0.75 0.20 | full 0.93 0.75 0.20 /user.slice/user-1000.slice/user@1000.service/at-spi-dbus-bus.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /user.slice/user-1000.slice/user@1000.service/gvfs-metadata.service
some 0.00 2.44 6.78 | full 0.00 2.43 6.74 /user.slice/user-1000.slice/user@1000.service/dbus.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /user.slice/user-1000.slice/user@1000.service/gvfs-mtp-volume-monitor.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /user.slice/user-1000.slice/user@1000.service/gvfs-afc-volume-monitor.service
some 44.99 28.30 19.41 | full 44.10 27.70 18.79 /user.slice/user-1000.slice/session-2.scope
some 0.00 0.31 0.53 | full 0.00 0.31 0.53 /init.scope
some 7.25 11.40 13.34 | full 7.23 11.32 13.24 /system.slice
some 0.00 0.01 0.02 | full 0.00 0.01 0.02 /system.slice/systemd-udevd.service
some 0.00 0.58 1.55 | full 0.00 0.58 1.55 /system.slice/cronie.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /system.slice/sys-kernel-config.mount
some 0.00 0.22 0.35 | full 0.00 0.22 0.35 /system.slice/polkit.service
some 0.00 0.06 0.20 | full 0.00 0.06 0.20 /system.slice/rtkit-daemon.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /system.slice/sys-kernel-debug.mount
some 0.00 0.14 0.62 | full 0.00 0.14 0.62 /system.slice/accounts-daemon.service
some 7.86 11.48 12.56 | full 7.84 11.42 12.51 /system.slice/lightdm.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /system.slice/ModemManager.service
some 0.00 1.82 5.47 | full 0.00 1.81 5.43 /system.slice/systemd-journald.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /system.slice/dev-mqueue.mount
some 0.00 1.64 4.07 | full 0.00 1.64 4.07 /system.slice/NetworkManager.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /system.slice/tmp.mount
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /system.slice/lvm2-lvmetad.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /system.slice/dev-disk-by\x2duuid-5d7355c0\x2dc131\x2d40c5\x2d8541\x2d1e04ad7c8b8d.swap
some 0.00 0.09 0.11 | full 0.00 0.09 0.11 /system.slice/upower.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /system.slice/udisks2.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /system.slice/dev-hugepages.mount
some 0.00 0.27 0.49 | full 0.00 0.27 0.48 /system.slice/dbus.service
some 0.00 0.00 0.00 | full 0.00 0.00 0.00 /system.slice/system-getty.slice
some 0.00 0.12 0.20 | full 0.00 0.12 0.20 /system.slice/avahi-daemon.service
some 0.00 0.18 0.30 | full 0.00 0.18 0.30 /system.slice/systemd-logind.service
```
psi2log
psi2log is a CLI tool that can check and log PSI metrics from specified target. It requires Linux
>= 4.20 with CONFIG_PSI=y
. Man page: psi2log.manpage.md.
Output example
```
$ psi2log
Starting psi2log
target: SYSTEM_WIDE
period: 2
------------------------------------------------------------------------------------------------------------------
some cpu pressure || some memory pressure | full memory pressure || some io pressure | full io pressure
---------------------||----------------------|----------------------||----------------------|---------------------
avg10 avg60 avg300 || avg10 avg60 avg300 | avg10 avg60 avg300 || avg10 avg60 avg300 | avg10 avg60 avg300
------ ------ ------ || ------ ------ ------ | ------ ------ ------ || ------ ------ ------ | ------ ------ ------
0.13 0.26 0.08 || 3.36 10.31 3.47 | 2.68 7.69 2.56 || 20.24 26.90 8.60 | 18.80 23.16 7.33
0.11 0.25 0.08 || 2.75 9.97 3.45 | 2.20 7.44 2.54 || 18.38 26.34 8.61 | 17.21 22.73 7.35
0.09 0.25 0.07 || 2.25 9.65 3.43 | 1.80 7.20 2.52 || 15.05 25.48 8.55 | 14.09 21.99 7.30
0.07 0.24 0.07 || 1.84 9.33 3.40 | 1.47 6.96 2.51 || 13.05 24.78 8.52 | 12.26 21.40 7.28
^C
Peak values: avg10 avg60 avg300
----------- ------ ------ ------
some cpu 0.13 0.26 0.08
----------- ------ ------ ------
some memory 3.36 10.31 3.47
full memory 2.68 7.69 2.56
----------- ------ ------ ------
some io 20.24 26.90 8.61
full io 18.80 23.16 7.35
$ psi2log -t /user.slice -l pm.log
Starting psi2log
target: /user.slice
period: 2
log file: pm.log
cgroup2 mountpoint: /sys/fs/cgroup
------------------------------------------------------------------------------------------------------------------
some cpu pressure || some memory pressure | full memory pressure || some io pressure | full io pressure
---------------------||----------------------|----------------------||----------------------|---------------------
avg10 avg60 avg300 || avg10 avg60 avg300 | avg10 avg60 avg300 || avg10 avg60 avg300 | avg10 avg60 avg300
------ ------ ------ || ------ ------ ------ | ------ ------ ------ || ------ ------ ------ | ------ ------ ------
28.32 11.97 3.03 || 0.00 1.05 1.65 | 0.00 0.85 1.33 || 0.55 7.79 7.21 | 0.54 7.52 6.80
29.53 12.72 3.25 || 0.00 1.01 1.64 | 0.00 0.82 1.32 || 0.81 7.60 7.17 | 0.44 7.27 6.76
29.80 13.32 3.44 || 0.00 0.98 1.63 | 0.00 0.79 1.31 || 0.66 7.35 7.12 | 0.36 7.03 6.71
29.83 13.86 3.62 || 0.00 0.95 1.62 | 0.00 0.77 1.30 || 0.54 7.11 7.08 | 0.30 6.80 6.66
29.86 14.39 3.80 || 0.00 0.91 1.60 | 0.00 0.74 1.29 || 0.44 6.88 7.03 | 0.24 6.58 6.62
30.07 14.94 3.99 || 0.00 0.88 1.59 | 0.00 0.72 1.28 || 0.36 6.65 6.98 | 0.20 6.36 6.57
^C
Peak values: avg10 avg60 avg300
----------- ------ ------ ------
some cpu 30.07 14.94 3.99
----------- ------ ------ ------
some memory 0.00 1.05 1.65
full memory 0.00 0.85 1.33
----------- ------ ------ ------
some io 0.81 7.79 7.21
full io 0.54 7.52 6.80
```
Contribution
- Use cases, feature requests and any questions are welcome.
- Pull requests in
dev
branch are welcome.
Documentation
License
This project is licensed under the terms of the MIT license.