From f10489d2ef8e76bbb3eb78c5b963abae3a4a8dc9 Mon Sep 17 00:00:00 2001 From: SJ Park Date: Fri, 10 Jul 2026 06:46:46 -0700 Subject: Docs/mm/damon/design: document attrs-only monitoring Update DAMON design document for the attributes only monitoring mode. Link: https://lore.kernel.org/20260710134651.18084-18-sj@kernel.org Signed-off-by: SJ Park Cc: David Hildenbrand Cc: Jonathan Corbet Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- 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 457d6e8bc787..6d79e7d69be8 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 ` regions using the access +:ref:`counter ` (``nr_accesses``). In some +use cases, however, users may want some of :ref:`attributes +` 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 ` 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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- cgit v1.2.3