Documentation/accounting/cgroupstats.rst

Source file repositories/reference/linux-study-clean/Documentation/accounting/cgroupstats.rst

File Facts

System: Linux kernel
Corpus path: Documentation/accounting/cgroupstats.rst
Extension: .rst
Size: 1444 bytes
Lines: 32
Domain: Support Tooling And Documentation
Bucket: Documentation
Inferred role: Support Tooling And Documentation: documentation
Status: atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

No C-style include directives detected by the generator.

Detected Declarations

No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

==================
Control Groupstats
==================

Control Groupstats is inspired by the discussion at
https://lore.kernel.org/r/461CF883.2030308@sw.ru and implements per cgroup statistics as
suggested by Andrew Morton in https://lore.kernel.org/r/20070411114927.1277d7c9.akpm@linux-foundation.org.

Per cgroup statistics infrastructure re-uses code from the taskstats
interface. A new set of cgroup operations are registered with commands
and attributes specific to cgroups. It should be very easy to
extend per cgroup statistics, by adding members to the cgroupstats
structure.

The current model for cgroupstats is a pull, a push model (to post
statistics on interesting events), should be very easy to add. Currently
user space requests for statistics by passing the cgroup path.
Statistics about the state of all the tasks in the cgroup is returned to
user space.

NOTE: We currently rely on delay accounting for extracting information
about tasks blocked on I/O. If CONFIG_TASK_DELAY_ACCT is disabled, this
information will not be available.

To extract cgroup statistics a utility very similar to getdelays.c
has been developed, the sample output of the utility is shown below::

  ~/balbir/cgroupstats # ./getdelays  -C "/sys/fs/cgroup/a"
  sleeping 1, blocked 0, running 1, stopped 0, uninterruptible 0
  ~/balbir/cgroupstats # ./getdelays  -C "/sys/fs/cgroup"
  sleeping 155, blocked 0, running 1, stopped 0, uninterruptible 2

Annotation

Atlas domain: Support Tooling And Documentation / Documentation.
Implementation status: atlas-only.

Implementation Notes

This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.