Docs/mm/damon/design: document node_mem_{used,free}_bp

Add description of DAMOS quota goal metrics for NUMA node utilization on
the DAMON deesign document.

Link: https://lkml.kernel.org/r/20250420194030.75838-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Yunjeong Mun <yunjeong.mun@sk.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index f12d33749329fd1d9926bd6cd8718fcfa0c37a38..728bf5754343956aae6c26e8ed2f8bfd847abd9d 100644 (file)
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst
@@ -550,10 +550,10 @@ aggressiveness (the quota) of the corresponding scheme.  For example, if DAMOS
 is under achieving the goal, DAMOS automatically increases the quota.  If DAMOS
 is over achieving the goal, it decreases the quota.
 
-The goal can be specified with three parameters, namely ``target_metric``,
-``target_value``, and ``current_value``.  The auto-tuning mechanism tries to
-make ``current_value`` of ``target_metric`` be same to ``target_value``.
-Currently, two ``target_metric`` are provided.
+The goal can be specified with four parameters, namely ``target_metric``,
+``target_value``, ``current_value`` and ``nid``.  The auto-tuning mechanism
+tries to make ``current_value`` of ``target_metric`` be same to
+``target_value``.
 
 - ``user_input``: User-provided value.  Users could use any metric that they
   has interest in for the value.  Use space main workload's latency or
@@ -565,6 +565,11 @@ Currently, two ``target_metric`` are provided.
   in microseconds that measured from last quota reset to next quota reset.
   DAMOS does the measurement on its own, so only ``target_value`` need to be
   set by users at the initial time.  In other words, DAMOS does self-feedback.
+- ``node_mem_used_bp``: Specific NUMA node's used memory ratio in bp (1/10,000).
+- ``node_mem_free_bp``: Specific NUMA node's free memory ratio in bp (1/10,000).
+
+``nid`` is optionally required for only ``node_mem_used_bp`` and
+``node_mem_free_bp`` to point the specific NUMA node.
 
 To know how user-space can set the tuning goal metric, the target value, and/or
 the current value via :ref:`DAMON sysfs interface <sysfs_interface>`, refer to