Commit cc7ceb1d14b0 ("mm/damon/stat: expose the current tuned
aggregation interval"), has introduced 'aggr_interval_us' parameter for
DAMON_STAT. But the new parameter is not yet documented. Document it
on the usage document for the module.
Signed-off-by: SeongJae Park <sj@kernel.org>
---
Documentation/admin-guide/mm/damon/stat.rst | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/Documentation/admin-guide/mm/damon/stat.rst b/Documentation/admin-guide/mm/damon/stat.rst
index 20f540a9d3d2..754f98d47617 100644
--- a/Documentation/admin-guide/mm/damon/stat.rst
+++ b/Documentation/admin-guide/mm/damon/stat.rst
@@ -10,6 +10,8 @@ on the system's entire physical memory using DAMON, and provides simplified
access monitoring results statistics, namely idle time percentiles and
estimated memory bandwidth.
+.. _damon_stat_monitoring_accuracy_overhead:
+
Monitoring Accuracy and Overhead
================================
@@ -19,7 +21,9 @@ overhead minimum. It auto-tunes the intervals aiming 4 % of observable access
events to be captured in each snapshot, while limiting the resulting sampling
interval to be 5 milliseconds in minimum and 10 seconds in maximum. On a few
production server systems, it resulted in consuming only 0.x % single CPU time,
-while capturing reasonable quality of access patterns.
+while capturing reasonable quality of access patterns. The tuning-resulting
+intervals can be retrieved via ``aggr_interval_us`` :ref:`parameter
+<damon_stat_aggr_interval_us>`.
Interface: Module Parameters
============================
@@ -41,6 +45,18 @@ You can enable DAMON_STAT by setting the value of this parameter as ``Y``.
Setting it as ``N`` disables DAMON_STAT. The default value is set by
``CONFIG_DAMON_STAT_ENABLED_DEFAULT`` build config option.
+.. _damon_stat_aggr_interval_us:
+
+aggr_interval_us
+----------------
+
+Auto-tuned aggregation time interval in microseconds.
+
+Users can read the aggregation interval of DAMON that is being used by the
+DAMON instance for DAMON_STAT. It is :ref:`auto-tuned
+<damon_stat_monitoring_accuracy_overhead>` and therefore the value is
+dynamically changed.
+
estimated_memory_bandwidth
--------------------------
--
2.47.3