Documentation/trace/rv/monitor_stall.rst

File Facts

System

Linux kernel

Corpus path

Documentation/trace/rv/monitor_stall.rst

Extension

.rst

Size

1630 bytes

Lines

44

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

Monitor stall
=============

- Name: stall - stalled task monitor
- Type: per-task hybrid automaton
- Author: Gabriele Monaco <gmonaco@redhat.com>

Description
-----------

The stalled task (stall) monitor is a sample per-task timed monitor that checks
if tasks are scheduled within a defined threshold after they are ready::

                        |
                        |
                        v
                      #==========================#
  +-----------------> H         dequeued         H
  |                   #==========================#
  |                     |
 sched_switch_wait      | sched_wakeup;reset(clk)
  |                     v
  |                   +--------------------------+ <+
  |                   |         enqueued         |  | sched_wakeup
  |                   | clk < threshold_jiffies  | -+
  |                   +--------------------------+
  |                     |                 ^
  |              sched_switch_in    sched_switch_preempt;reset(clk)
  |                     v                 |
  |                   +--------------------------+
  +------------------ |         running          |
                      +--------------------------+
                        ^ sched_switch_in      |
                        | sched_wakeup         |
                        +----------------------+

The threshold can be configured as a parameter by either booting with the
``stall.threshold_jiffies=<new value>`` argument or writing a new value to
``/sys/module/stall/parameters/threshold_jiffies``.

Specification
-------------
Graphviz Dot file in tools/verification/models/stall.dot

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.