[RFC PATCH 8/8] Docs/admin-guide/mm/damon/usage: add intervals_goal directory on the hierarchy
From: SeongJae Park <sj@kernel.org>
Date: 2025-02-13 01:45:01
Also in:
damon, linux-mm, lkml
Subsystem:
damon, documentation, memory management - misc, the rest · Maintainers:
SJ Park, Jonathan Corbet, Andrew Morton, David Hildenbrand, Linus Torvalds
Document DAMON sysfs interface usage for DAMON sampling and aggregation intervals auto-tuning. Signed-off-by: SeongJae Park <sj@kernel.org> --- 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:
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2.39.5