From: SeongJae Park <sj@kernel.org>
Cc: SeongJae Park <sj@kernel.org>,
"Liam R. Howlett" <liam@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@kernel.org>,
Jonathan Corbet <corbet@lwn.net>,
Lorenzo Stoakes <ljs@kernel.org>, Michal Hocko <mhocko@suse.com>,
Mike Rapoport <rppt@kernel.org>,
Shuah Khan <skhan@linuxfoundation.org>,
Suren Baghdasaryan <surenb@google.com>,
Vlastimil Babka <vbabka@kernel.org>,
damon@lists.linux.dev, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: [RFC PATCH 19/19] Docs/admin-guide/mm/damon/usage: document data attributes monitoring
Date: Sun, 26 Apr 2026 13:52:20 -0700 [thread overview]
Message-ID: <20260426205222.93895-20-sj@kernel.org> (raw)
In-Reply-To: <20260426205222.93895-1-sj@kernel.org>
Update DAMON usage document for the newly added data attributes
monitoring feature.
Signed-off-by: SeongJae Park <sj@kernel.org>
---
Documentation/admin-guide/mm/damon/usage.rst | 44 ++++++++++++++++----
Documentation/mm/damon/design.rst | 2 +
2 files changed, 39 insertions(+), 7 deletions(-)
diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst
index 11c75a598393c..397820ac8bbb0 100644
--- a/Documentation/admin-guide/mm/damon/usage.rst
+++ b/Documentation/admin-guide/mm/damon/usage.rst
@@ -72,6 +72,11 @@ comma (",").
│ │ │ │ │ │ intervals/sample_us,aggr_us,update_us
│ │ │ │ │ │ │ intervals_goal/access_bp,aggrs,min_sample_us,max_sample_us
│ │ │ │ │ │ nr_regions/min,max
+ │ │ │ │ │ │ :ref:`probes <damon_usage_sysfs_probes>`/nr_probes
+ │ │ │ │ │ │ │ 0/filters/nr_filters
+ │ │ │ │ │ │ │ │ │ 0/type,matching,allow
+ │ │ │ │ │ │ │ │ │ ...
+ │ │ │ │ │ │ │ │ ...
│ │ │ │ │ :ref:`targets <sysfs_targets>`/nr_targets
│ │ │ │ │ │ :ref:`0 <sysfs_target>`/pid_target,obsolete_target
│ │ │ │ │ │ │ :ref:`regions <sysfs_regions>`/nr_regions
@@ -97,7 +102,8 @@ comma (",").
│ │ │ │ │ │ │ │ 0/id,weight
│ │ │ │ │ │ │ :ref:`stats <sysfs_schemes_stats>`/nr_tried,sz_tried,nr_applied,sz_applied,sz_ops_filter_passed,qt_exceeds,nr_snapshots,max_nr_snapshots
│ │ │ │ │ │ │ :ref:`tried_regions <sysfs_schemes_tried_regions>`/total_bytes
- │ │ │ │ │ │ │ │ 0/start,end,nr_accesses,age,sz_filter_passed
+ │ │ │ │ │ │ │ │ 0/start,end,nr_accesses,age,sz_filter_passed,
+ │ │ │ │ │ │ │ │ probe_hits
│ │ │ │ │ │ │ │ ...
│ │ │ │ │ │ ...
│ │ │ │ ...
@@ -227,8 +233,8 @@ contexts/<N>/monitoring_attrs/
Files for specifying attributes of the monitoring including required quality
and efficiency of the monitoring are in ``monitoring_attrs`` directory.
-Specifically, two directories, ``intervals`` and ``nr_regions`` exist in this
-directory.
+Specifically, two directories, ``intervals``, ``nr_regions`` and ``probes``
+exist in this directory.
Under ``intervals`` directory, three files for DAMON's sampling interval
(``sample_us``), aggregation interval (``aggr_us``), and update interval
@@ -262,6 +268,27 @@ 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.
+.. _damon_usage_sysfs_probes:
+
+contexts/<N>/monitoring_attrs/probes/
+-------------------------------------
+
+A directory for registering :ref:`data attributes monitoring
+<damon_design_data_attrs_monitoring>` probes.
+
+In the beginning, this directory has only one file, ``nr_probes``. Writing a
+number (``N``) to the file creates the number of child directories named ``0``
+to ``N-1``. Each directory represents each monitoring probe.
+
+In each probe directory, one directory, ``filters`` exist. The directory
+contains files for installingt filters for the probe, that is used to determine
+the data attribute for the probe.
+
+In the beginning, ``filters`` directory has only one file, ``nr_filters``.
+Writing a number (``N``) to the file creates the number of child directories
+named ``0`` to ``N-1``. Each directory represents each filter and work in a
+way similar to that for :ref:`DAMOS filter <sysfs_filters>`.
+
.. _sysfs_targets:
contexts/<N>/targets/
@@ -614,10 +641,13 @@ set the ``access pattern`` as their interested pattern that they want to query.
tried_regions/<N>/
------------------
-In each region directory, you will find five files (``start``, ``end``,
-``nr_accesses``, ``age``, and ``sz_filter_passed``). Reading the files will
-show the properties of the region that corresponding DAMON-based operation
-scheme ``action`` has tried to be applied.
+In each region directory, you will find six files (``start``, ``end``,
+``nr_accesses``, ``age``, ``sz_filter_passed`` and ``probe_hits``). Reading
+the files will show the properties of the region that corresponding DAMON-based
+operation scheme ``action`` has tried to be applied.
+
+Reading ``probe_hists`` shows the number of data attributes monitoring
+probe-hit positive samples of the region.
Example
~~~~~~~
diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index bada2010ad1ca..2b68a1880a4a1 100644
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst
@@ -276,6 +276,8 @@ interval``, DAMON checks if the region's size and access frequency
(``nr_accesses``) has significantly changed. If so, the counter is reset to
zero. Otherwise, the counter is increased.
+.. _damon_design_data_attrs_monitoring:
+
Data Attributes Monitoring
~~~~~~~~~~~~~~~~~~~~~~~~~~
--
2.47.3
prev parent reply other threads:[~2026-04-26 20:52 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-26 20:52 [RFC PATCH 00/19] mm/damon: introduce data attributes monitoring SeongJae Park
2026-04-26 20:52 ` [RFC PATCH 18/19] Docs/mm/damon/design: document " SeongJae Park
2026-04-26 20:52 ` SeongJae Park [this message]
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