ctinfo - Linux
Overview
ctinfo
is a command-line utility used to gather detailed information and statistics about control groups (cgroups) in a Linux system. It offers insights into resource usage, hierarchies, and constraints applied to processes and tasks.
Syntax
ctinfo [options] [--] [cgroup-path]...
Options/Flags
-h, --help
: Display help and exit.-v, --version
: Print version information and exit.-i, --info
: Get general information about the specified cgroup.-s, --stats
: Show resource usage statistics for the cgroup.-p, --processes
: List processes running inside the cgroup.-d, --drop
: Exclude specific subsystems or groups from the output.-a, --all
: Display all cgroups and their properties, even inactive ones.-l, --long
: Output more detailed information for each cgroup.
Examples
Get basic information about a cgroup:
ctinfo /sys/fs/cgroup/cpu/test
Show resource usage statistics for a cgroup:
ctinfo -s /sys/fs/cgroup/memory/foo
List all active cgroups in the system:
ctinfo -a
Display information about specific subsystems:
ctinfo -d cpu,memory /sys/fs/cgroup
Common Issues
- Incorrect cgroup path: Ensure the specified cgroup path is valid and exists.
- Permission denied: Check user permissions to access the cgroup filesystem.
- Process not found: Processes may not be visible in cgroup listings if they are stopped or have exited.
Integration
ctinfo
can be used in combination with other commands for system monitoring and performance analysis:
top
: Integratectinfo
intotop
to display cgroup usage statistics alongside process information.ps
: Usectinfo
to identify cgroups associated with specific processes and their usage patterns.
Related Commands
cgcreate
: Create a new cgroup.cgdelete
: Delete a cgroup.cgset
: Set cgroup parameters.cgexec
: Execute a command within a specific cgroup.systemd-cgls
: List and manage cgroups from within systemd.