Commit 4cc00d41 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
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Docs/mm/damon/design: document DAMOS_QUOTA_NODE_MEMCG_{USED,FREE}_BP 

Update design doc for the newly added two DAMOS quota auto-tuning target
goal metrics, DAMOS_QUOTA_NODE_MEMCG_{USED,FREE}_BP.

Link: https://lkml.kernel.org/r/20251017212706.183502-9-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent c2fbf2da

Documentation/mm/damon/design.rst

+15 −6
Original line number Diff line number Diff line
@@ -564,9 +564,9 @@ 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 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

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

``target_value``.



- ``user_input``: User-provided value.  Users could use any metric that they
@@ -581,9 +581,18 @@ tries to make ``current_value`` of ``target_metric`` be same to 
  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.

- ``node_memcg_used_bp``: Specific cgroup's node used memory ratio for a

  specific NUMA node, in bp (1/10,000).

- ``node_memcg_free_bp``: Specific cgroup's node unused memory ratio for a

  specific NUMA node, in bp (1/10,000).



``nid`` is optionally required for only ``node_mem_used_bp``,

``node_mem_free_bp``, ``node_memcg_used_bp`` and ``node_memcg_free_bp`` to

point the specific NUMA node.



``path`` is optionally required for only ``node_memcg_used_bp`` and

``node_memcg_free_bp`` to point the path to the cgroup.  The value should be

the path of the memory cgroup from the cgroups mount point.



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