Cgroups

This article is a Draft. Help us to complete it.

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-cgls
systemd-cgls memory
systemd-cgtop

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
• Cgroups: cgroup mountpoint does not exist: unknown

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
• cgroups: cgcreate, cgroups v2
• 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
• IO performance: iotop, iostat, sar -d, fio, nmon, vmstat -d, dd, nmon, stress
• Linux Kernel: namespaces, Cgroups, OOM, proc, Linux Kernel changelog, sysctl, userfaultfd, Grub, ENOSPC, ENOMEM, DKMS, syscall, Transparent huge pages, smatch, sysfs, vm.swappiness, CFS, Runlevel, Jens Axboe, Consistent Network Device Naming, Initial ramdisk (initrd), modprobe, MTD, Linux Kernel vulnerabilities, /sys/kernel/, KernelCare, unix://, Data Plane Development Kit (DPDK)

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