Committing a monitoring target with empty target regions is for keeping the current monitoring results. This behavior was introduced by commit 973233600676 ("mm/damon/sysfs: update monitoring target regions for online input commit"). The behavior is not documented, though. Update the usage document for clarifying this behavior. Signed-off-by: SeongJae Park --- Documentation/admin-guide/mm/damon/usage.rst | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst index d8a3d6e740b3..9991dad60fcf 100644 --- a/Documentation/admin-guide/mm/damon/usage.rst +++ b/Documentation/admin-guide/mm/damon/usage.rst @@ -134,7 +134,8 @@ Users can write below commands for the kdamond to the ``state`` file. - ``on``: Start running. - ``off``: Stop running. - ``commit``: Read the user inputs in the sysfs files except ``state`` file - again. + again. Monitoring :ref:`target region ` inputs are also be + ignored if no target region is specified. - ``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 @@ -296,6 +297,11 @@ In the beginning, this directory has only one file, ``nr_regions``. Writing a number (``N``) to the file creates the number of child directories named ``0`` to ``N-1``. Each directory represents each initial monitoring target region. +If ``nr_regions`` is zero when committing new DAMON parameters online (writing +``commit`` to ``state`` file of :ref:`kdamond `), the commit +logic ignores the target regions. In other words, the current monitoring +results for the target are preserved. + .. _sysfs_region: regions// -- 2.47.3