From b3b95a3594530643972220a70d738db96544be45 Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Sun, 20 Apr 2025 12:40:27 -0700 Subject: [PATCH] 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 Cc: Jonathan Corbet Cc: Yunjeong Mun Signed-off-by: Andrew Morton --- Documentation/mm/damon/design.rst | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst index f12d33749329..728bf5754343 100644 --- 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 `, refer to -- 2.25.1