[RFC PATCH 5/5] Docs/admin-guide/mm/damon/usage: document goal_tuner sysfs file

[SeongJae Park]

Update the DAMON usage document for the new sysfs file for the goal
based quota auto-tuning, 'goal_tuner'.

Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
---
 Documentation/admin-guide/mm/damon/usage.rst | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst
index b0f3969b6b3b1..534e1199cf091 100644
--- a/Documentation/admin-guide/mm/damon/usage.rst
+++ b/Documentation/admin-guide/mm/damon/usage.rst
@@ -83,7 +83,7 @@ comma (",").
     │ │ │ │ │ │ │ │ sz/min,max
     │ │ │ │ │ │ │ │ nr_accesses/min,max
     │ │ │ │ │ │ │ │ age/min,max
-    │ │ │ │ │ │ │ :ref:`quotas <sysfs_quotas>`/ms,bytes,reset_interval_ms,effective_bytes
+    │ │ │ │ │ │ │ :ref:`quotas <sysfs_quotas>`/ms,bytes,reset_interval_ms,effective_bytes,goal_tuner
     │ │ │ │ │ │ │ │ weights/sz_permil,nr_accesses_permil,age_permil
     │ │ │ │ │ │ │ │ :ref:`goals <sysfs_schemes_quota_goals>`/nr_goals
     │ │ │ │ │ │ │ │ │ 0/target_metric,target_value,current_value,nid,path
@@ -377,9 +377,9 @@ schemes/<N>/quotas/
 The directory for the :ref:`quotas <damon_design_damos_quotas>` of the given
 DAMON-based operation scheme.
 
-Under ``quotas`` directory, four files (``ms``, ``bytes``,
-``reset_interval_ms``, ``effective_bytes``) and two directories (``weights`` and
-``goals``) exist.
+Under ``quotas`` directory, five files (``ms``, ``bytes``,
+``reset_interval_ms``, ``effective_bytes`` and ``goal_tuner``) and two
+directories (``weights`` and ``goals``) exist.
 
 You can set the ``time quota`` in milliseconds, ``size quota`` in bytes, and
 ``reset interval`` in milliseconds by writing the values to the three files,
@@ -390,6 +390,14 @@ apply the action to only up to ``bytes`` bytes of memory regions within the
 quota limits unless at least one :ref:`goal <sysfs_schemes_quota_goals>` is
 set.
 
+You can set the goal-based effective quota auto-tuning algorithm to use, by
+writing the algorithm name to ``goal_tuner`` file.  Reading the file returns
+the currently selected tuner algorithm.  Refer to the design documentation of
+:ref:`automatic quota tuning goals <damon_design_damos_quotas_auto_tuning>` for
+the background design of the feature and the name of the selectable algorithms.
+Refer to :ref:`goals directory <sysfs_schemes_quota_goals>` for the goals
+setup.
+
 The time quota is internally transformed to a size quota.  Between the
 transformed size quota and user-specified size quota, smaller one is applied.
 Based on the user-specified :ref:`goal <sysfs_schemes_quota_goals>`, the
-- 
2.47.3