MIRRORS/linux-yocto
1
0
Fork 0
mirror of git://git.yoctoproject.org/linux-yocto.git synced 2025-10-22 23:13:01 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

Docs/admin-guide/mm/damon/usage: add intervals_goal directory on the hierarchy

Browse Source 
Document DAMON sysfs interface usage for DAMON sampling and aggregation
intervals auto-tuning.

Link: https://lkml.kernel.org/r/20250303221726.484227-9-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
SeongJae Park 2025-03-03 14:17:26 -08:00 committed by Andrew Morton
parent e2b23dc623
commit b243d666d1
2 changed files with 29 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
Documentation/admin-guide/mm/damon/usage.rst
View File

@ -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/access_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
``access_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/

4
Documentation/mm/damon/design.rst
View File

@ -366,6 +366,10 @@ is recommended. Note that Parreto principle (80/20 rule) has applied twice.
That is, assumes 4% (20% of 20%) DAMON-observed access events ratio (source)
to capture 64% (80% multipled by 80%) real access events (outcomes).
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: