[PATCH 17/19] Docs/mm/damon/design: document attrs-only monitoring
From: SJ Park <sj@kernel.org>
Date: 2026-07-10 13:47:06
Also in:
damon, linux-mm, lkml
Subsystem:
damon, documentation, memory management - misc, the rest · Maintainers:
SeongJae Park, Jonathan Corbet, Andrew Morton, David Hildenbrand, Linus Torvalds
Update DAMON design document for the attributes only monitoring mode. Signed-off-by: SJ Park <sj@kernel.org> --- Documentation/mm/damon/design.rst | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index 457d6e8bc7878..6d79e7d69be84 100644
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst@@ -316,6 +316,26 @@ Another way to do this for higher accuracy is using :ref:`DAMOS filter information in page level. But, because it is operated in page level, the overhead is proportional to the size of the memory. +Data Attributes-only Monitoring +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Data access is the primary monitoring information for DAMON. Hence it +:ref:`adjusts <damon_design_data_attrs_monitoring>` regions using the access +:ref:`counter <damon_design_region_based_sampling>` (``nr_accesses``). In some +use cases, however, users may want some of :ref:`attributes +<damon_design_data_attrs_monitoring>` to be the primary information. + +Data attributes-only monitoring mode supports this use case. For the mode, +each attribute probe has their priority weight value. Users can describe by +what combination of the attributes the primary information is decided, by +setting the priority weight value. If the total sum of the weights is not +zero, the mode is enabled. The regions adjustment mechanism uses the weighted +sum of the :ref:`probe hit counts <damon_design_data_attrs_monitoring>` instead +of ``nr_accesses`` in the case. When the mode is enabled, access monitoring is +automatically turned off. The access counter (``nr_accesses``) will always be +zero and not updated. Hence the mode is called Data Attributes "only" +monitoring. + Dynamic Target Space Updates Handling ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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2.47.3