Document DAMON sysfs interface usage for DAMON sampling and aggregation
intervals auto-tuning.
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
---
Documentation/admin-guide/mm/damon/usage.rst | 25 ++++++++++++++++++++
Documentation/mm/damon/design.rst | 4 ++++
2 files changed, 29 insertions(+)
diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst
index 51af66c208c5..8970efce32f0 100644
--- a/Documentation/admin-guide/mm/damon/usage.rst
+++ b/Documentation/admin-guide/mm/damon/usage.rst
@@ -64,6 +64,7 @@ comma (",").
│ │ │ │ :ref:`0 <sysfs_context>`/avail_operations,operations
│ │ │ │ │ :ref:`monitoring_attrs <sysfs_monitoring_attrs>`/
│ │ │ │ │ │ intervals/sample_us,aggr_us,update_us
+ │ │ │ │ │ │ │ intervals_goal/samples_bp,aggrs,min_sample_us,max_sample_us
│ │ │ │ │ │ nr_regions/min,max
│ │ │ │ │ :ref:`targets <sysfs_targets>`/nr_targets
│ │ │ │ │ │ :ref:`0 <sysfs_target>`/pid_target
@@ -132,6 +133,11 @@ Users can write below commands for the kdamond to the ``state`` file.
- ``off``: Stop running.
- ``commit``: Read the user inputs in the sysfs files except ``state`` file
again.
+- ``update_tuned_intervals``: Update the contents of ``sample_us`` and
+ ``aggr_us`` files of the kdamond with the auto-tuning applied ``sampling
+ interval`` and ``aggregation interval`` for the files. Please refer to
+ :ref:`intervals_goal section <damon_usage_sysfs_monitoring_intervals_goal>`
+ for more details.
- ``commit_schemes_quota_goals``: Read the DAMON-based operation schemes'
:ref:`quota goals <sysfs_schemes_quota_goals>`.
- ``update_schemes_stats``: Update the contents of stats files for each
@@ -213,6 +219,25 @@ writing to and rading from the files.
For more details about the intervals and monitoring regions range, please refer
to the Design document (:doc:`/mm/damon/design`).
+.. _damon_usage_sysfs_monitoring_intervals_goal:
+
+contexts/<N>/monitoring_attrs/intervals/intervals_goal/
+-------------------------------------------------------
+
+Under the ``intervals`` directory, one directory for automated tuning of
+``sample_us`` and ``aggr_us``, namely ``intervals_goal`` directory also exists.
+Under the directory, four files for the auto-tuning control, namely
+``samples_bp``, ``aggrs``, ``min_sample_us`` and ``max_sample_us`` exist.
+Please refer to the :ref:`design document of the feature
+<damon_design_monitoring_intervals_autotuning>` for the internal of the tuning
+mechanism. Reading and writing the four files under ``intervals_goal``
+directory shows and updates the tuning parameters that described in the
+:ref:design doc <damon_design_monitoring_intervals_autotuning>` with the same
+names. The tuning starts with the user-set ``sample_us`` and ``aggr_us``. The
+tuning-applied current values of the two intervals can be read from the
+``sample_us`` and ``aggr_us`` files after writing ``update_tuned_intervals`` to
+the ``state`` file.
+
.. _sysfs_targets:
contexts/<N>/targets/
diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index c8e906ac3965..940409abc23f 100644
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst
@@ -354,6 +354,10 @@ The tuning is turned off by default, and need to be set explicitly by the user.
As a rule of thumbs and the Parreto principle, 20% access samples ratio target
is recommended.
+To know how user-space can use this feature via :ref:`DAMON sysfs interface
+<sysfs_interface>`, refer to :ref:`intervals_goal <sysfs_scheme>` part of
+the documentation.
+
.. _damon_design_damos:
--
2.39.5
