Merge "Enable stalld to protect low-priority tasks from starvation (dsR10)"

doc/source/system_configuration/kubernetes/configure-stall-daemon-b38ece463e88.rst

@@ -0,0 +1,99 @@
+.. WARNING: Add no lines of text between the label immediately following
+.. and the title.
+
+.. _configure-stall-daemon-b38ece463e88:
+
+======================
+Configure stall daemon
+======================
+
+Stalld (stall daemon) is a program that monitors threads to protect critical
+but low-scheduling-priority tasks from starvation. It is configured using
+host-labels.
+
+The supported host-labels are:
+
+-   ``starlingx.io/stalld``
+
+    supported values are: “enabled”, “disabled”
+
+-   ``starlingx.io/stalld_cpu_functions``
+
+    supported values are: “all”, “application”, “application-isolated”
+
+Custom stalld labels are supported.
+
+To enable stalld, run:
+
+.. code-block:: none
+
+    system host-label-assign <host> starlingx.io/stalld=enabled
+
+To disable stalld, run:
+
+.. code-block:: none
+
+    system host-label-assign <host> starlingx.io/stalld=disabled
+
+or
+
+.. code-block:: none
+
+    system host-label-remove <host> starlingx.io/stalld
+
+Configure CPUs being monitored by Stalld
+----------------------------------------
+
+To have stalld monitor all CPUs.
+
+.. code-block:: none
+
+    system host-label-assign <host> starlingx.io/stalld_cpu_functions=all
+
+To have stalld monitor all application CPUs.
+
+.. note::
+
+    This also includes application-isolated CPUs.
+
+.. code-block:: none
+
+    system host-label-assign <host> starlingx.io/stalld_cpu_functions=application
+
+To have stalld monitor only application-isolated CPUs.
+
+.. code-block:: none
+
+    system host-label-assign <host> starlingx.io/stalld_cpu_functions=application-isolated
+
+Configure Custom Stalld Parameters
+----------------------------------
+
+You can specify custom parameters that are passed as startup arguments to
+stalld. The parameters are specified in the following format:
+
+``system host-label assign <node> starlingx.io/stalld.xxxx=yyyy``
+
+which becomes ``stalld --xxxx=yyyy``
+
+``system host-label assign <node> starlingx.io/stalld.zzzz=''``
+
+which becomes ``stalld --zzzz``
+
+Some examples:
+
+``system host-label assign controller-0``
+
+``starlingx.io/stalld.boost_period=1000000000``
+
+``starlingx.io/stalld.boost_runtime=20000``
+
+``starlingx.io/stalld.boost_duration=1``
+
+``starlingx.io/stalld.starving_threshold=2``
+
+``starlingx.io/stalld.verbose=''``
+
+``starlings.io/stalld.log_kmsg=''``
+
+``starlingx.io/stalld.force_fifo=''``

doc/source/system_configuration/kubernetes/index-sysconf-kub-78f0e1e9ca5a.rst

@@ -223,4 +223,13 @@ Disable SCTP Autoload in the Kernel
 .. toctree::
    :maxdepth: 1
 
-   disable-sctp-autoload-in-the-kernel-e16de9f1204f
+   disable-sctp-autoload-in-the-kernel-e16de9f1204f
+
+----------------------
+Configure stall daemon
+----------------------
+
+.. toctree::
+   :maxdepth: 1
+
+   configure-stall-daemon-b38ece463e88