Cgroups

wikipedia:cgroups (2007, archlinux) (control groups) is a Linux kernel feature that:

• limits
• accounts for
• isolates

Resource usage (CPU, memory, disk I/O, etc.) of a group of processes.

Packages

cgroups functionality that was released in Linux Kernel version 2.6.24

Packages:

• cgroup-lite: cgroups-mount, cgroups-umount
• cgroup-tools: cgcreate, cgexec, lscgroup among others
• cgroupfs-mount

• systemd-cgtop
• systemd-cgls
• systemd-cgls memory

Basic Commands

• Create a group : cgcreate -g memory:myGroup
• cgexec -g memory:myGroup YOUR_PROGRAM_TO_EXEC

• You can use cgget to view the current limits, usage, & high watermarks of the group:

sudo cgget -g memory:/myGroup|grep bytes 
memory.kmem.tcp.usage_in_bytes: 0
memory.soft_limit_in_bytes: 9223372036854771712
memory.kmem.tcp.max_usage_in_bytes: 0
memory.max_usage_in_bytes: 0
memory.limit_in_bytes: 9223372036854771712
memory.kmem.max_usage_in_bytes: 0
memory.usage_in_bytes: 0
memory.kmem.limit_in_bytes: 9223372036854771712
memory.kmem.usage_in_bytes: 0
memory.kmem.tcp.limit_in_bytes: 9223372036854771712

I/O control, more accurate cgroup I/O control with blk-iocost

Related terms

• ulimit
• systemd-run
• Cgroups: cgroup mountpoint does not exist: unknown
• Linux Kernel namespaces
• Cgroups v2

Sep 21 11:23:14 yourhostame dockerd[1850]: time="2023-09-21T11:23:14.096834108Z" level=warning msg="Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap."

Activities

• Read https://wiki.archlinux.org/index.php/cgroups
• How to limit to CPU and Memory : cgcreate

See also

• systemd-cgtop, docker stats
• netdata cgroups plugin
• Containers, OCI: Docker (dockerd), containerd, runc, Podman, buildah, skopeo, lxd, Container Registry, Service mesh, Windows Server containers, Containerpilot, CoreOS, CAdvisor, Containers networking, Container scanning, cosign, CRI, CRI-O, initContainers, Sidecar container, Container images, latest, Development Containers, LXC
• cgroups: cgcreate, cgroups v2, cgexec, cgclassify

https://kernelnewbies.org/Linux_5.4#More_accurate_cgroup_I.2FO_control_with_blk-iocost

https://www.freedesktop.org/software/systemd/man/systemd-cgtop.html