[RFC PATCH 0/3] Add scheduler overview documentation

From: John Mathew
Date: Wed Apr 01 2020 - 06:02:53 EST


Hi all,

Based on our investigation in the area of the MIPS scheduler context
switch we wish to share our learnings about the kernel scheduler in
the form of kernel documentation. Investigations were done mostly by
stepping through the code using GDB and code inspection. The aim of
the patchset is to provide a brief overview of the kernel scheduler
starting from a brief history, the overview of the kernel structs
used by the scheduler, scheduler invocation and context switch. We
have also added a small section on scheduler state modelling
possibilities. In order to add these subjects we have restructured
the existing scheduler documentation so as to put them in to suitable
sections. We hope the new structure will enable easy extension of the
scheduler documentation.

Patch 1 creates place holders and new structure for the scheduler documentation.
The main sections are
- Scheduler overview: Overview of the scheduler.
- CFS: A section dedicated to CFS scheduler.
- Process context switching: Context switching overview.
- Scheduler features: We thought most of the existing documentation can be moved
here.
- Architecture Specific Scheduler Implementation Differences: Aimed for each
architecture and future updates.
- Scheduler Debugging Interface: For scheduler diagnostics and utilities
- Scheduler related functions: Scheduler API reference.

Patch 2: Adds documentation for the place holders of the Scheduler overview,
Scheduler State Transition and CFS sections.

Patch 3: Adds documentation for the place holder of the Process context switching
and add 2 new sections to for x86 and MIPS context switch.


John Mathew (3):
docs: scheduler: Restructure scheduler documentation.
docs: scheduler: Add scheduler overview documentation
docs: scheduler: Add introduction to scheduler context-switch

Documentation/scheduler/arch-specific.rst | 14 +
Documentation/scheduler/cfs-data-structs.rst | 208 ++++++++++++++
Documentation/scheduler/cfs-overview.rst | 46 ++++
.../scheduler/cfs-sched-overview.rst | 17 ++
Documentation/scheduler/context-switching.rst | 71 +++++
Documentation/scheduler/index.rst | 31 ++-
.../scheduler/mips-context-switch.rst | 78 ++++++
Documentation/scheduler/overview.rst | 260 ++++++++++++++++++
Documentation/scheduler/sched-debugging.rst | 14 +
Documentation/scheduler/sched-features.rst | 20 ++
Documentation/scheduler/scheduler-api.rst | 34 +++
.../scheduler/x86-context-switch.rst | 59 ++++
kernel/sched/core.c | 36 ++-
13 files changed, 867 insertions(+), 21 deletions(-)
create mode 100644 Documentation/scheduler/arch-specific.rst
create mode 100644 Documentation/scheduler/cfs-data-structs.rst
create mode 100644 Documentation/scheduler/cfs-overview.rst
create mode 100644 Documentation/scheduler/cfs-sched-overview.rst
create mode 100644 Documentation/scheduler/context-switching.rst
create mode 100644 Documentation/scheduler/mips-context-switch.rst
create mode 100644 Documentation/scheduler/overview.rst
create mode 100644 Documentation/scheduler/sched-debugging.rst
create mode 100644 Documentation/scheduler/sched-features.rst
create mode 100644 Documentation/scheduler/scheduler-api.rst
create mode 100644 Documentation/scheduler/x86-context-switch.rst

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2.17.1