[RFC PATCH 0/2] mm/damon/sysfs: document filters/ directory as deprecated

SeongJae Park
2026-04-21T04:49:45Z

Commit ab71d2d30121 ("mm/damon/sysfs-schemes: let
damon_sysfs_scheme_set_filters() be used for different named
directories") introduced alternatives of 'filters' directory, namely
core_filters/ and 'ops_filters/ directories. Now the alternatives are
well stabilized and ready for all users. All filters/ directory use
cases are expected to be able to be migrated to the alternatives. An
LTS kernel having the alternatives, namely 6.18.y, is also released.
Existence of filters/ directory is only confusing.

It would be better not immediately removing the directory, though.
There could be users that need time before migrating to the
alternatives. There might be unexpected use cases that the alternatives
cannot support. Doing the deprecation step by step across multiple
years like DAMON debugfs deprecation would be safer. Start the
deprecation changes by announcing the deprecation on the documents.

Every year, one more action for completely removing the directory will
be followed, like DAMON debugfs deprecation did. Following yearly
actions are currently expected. In 2027, deprecation warning kernel
messages will be printed once, for use of filters/ directory. In 2028,
filters/ directory will be renamed to filters_DEPRECATED/. In 2029,
filters_DEPRECATED/ directory will be removed.

SeongJae Park (2):
Docs/admin-guide/mm/damon/usage: mark scheme filters sysfs dir as
deprecated
Docs/ABI/damon: mark schemes//filters/ deprecated

.../ABI/testing/sysfs-kernel-mm-damon | 62 ++++++++++---------
Documentation/admin-guide/mm/damon/usage.rst | 7 ++-
2 files changed, 38 insertions(+), 31 deletions(-)

base-commit: 68f9cad2eca9a05a70ec47a90f2ae97aa2363a9c
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2.47.3