[RFC PATCH v2 05/10] Docs/mm/damon/design: document the goal-based quota tuner selections

SeongJae Park
2026-03-04T04:41:29Z

Update the design document for the newly added goal-based quota tuner
selection feature.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
Documentation/mm/damon/design.rst | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index dd64f5d7f3193..28d932ceaf7ed 100644
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst
@@ -564,6 +564,18 @@ 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.

+There are two such tuning algorithms that users can select as they need.
+
+- ``consist``: A proportional feedback loop based algorithm. Tries to find an
+ optimum quota that should be consistently kept, to keep achieving the goal.
+ Useful for kernel-only operation on dynamic and long-running environments.
+ This is the default selection. If unsure, use this.
+- ``temporal``: More straightforward algorithm. Tries to achieve the goal as
+ fast as possible, using maximum allowed quota, but only for a temporal short
+ time. When the quota is under-achieved, this algorithm keeps tuning quota to
+ a maximum allowed one. Once the quota is [over]-achieved, this sets the
+ quota zero. Useful for deterministic control required environments.
+
The goal can be specified with five parameters, namely ``target_metric``,
``target_value``, ``current_value``, ``nid`` and ``path``. The auto-tuning
mechanism tries to make ``current_value`` of ``target_metric`` be same to
--
2.47.3