[ros2_control_node] Add option to set the CPU affinity (backport #1852)…

… (#1856)

controller_manager/src/ros2_control_node.cpp

@@ -44,6 +44,16 @@ int main(int argc, char ** argv)
 
   auto cm = std::make_shared<controller_manager::ControllerManager>(executor, manager_node_name);
 
+  const int cpu_affinity = cm->get_parameter_or<int>("cpu_affinity", -1);
+  if (cpu_affinity >= 0)
+  {
+    const auto affinity_result = realtime_tools::set_current_thread_affinity(cpu_affinity);
+    if (!affinity_result.first)
+    {
+      RCLCPP_WARN(
+        cm->get_logger(), "Unable to set the CPU affinity : '%s'", affinity_result.second.c_str());
+    }
+  }
   const bool lock_memory = cm->get_parameter_or<bool>("lock_memory", true);
   std::string message;
   if (lock_memory && !realtime_tools::lock_memory(message))

doc/release_notes.rst

@@ -19,3 +19,4 @@ controller_manager
 * The ``ros2_control_node`` node now accepts the ``thread_priority`` parameter to set the scheduler priority of the controller_manager's RT thread (`#1820 <https://github.com/ros-controls/ros2_control/pull/1820>`_).
 * Added support for the wildcard entries for the controller configuration files (`#1724 <https://github.com/ros-controls/ros2_control/pull/1724>`_).
 * The ``ros2_control_node`` node has a new ``lock_memory`` parameter to lock memory at startup to physical RAM in order to avoid page faults (`#1822 <https://github.com/ros-controls/ros2_control/pull/1822>`_).
+* The ``ros2_control_node`` node has a new ``cpu_affinity`` parameter to bind the process to a specific CPU core. By default, this is not enabled. (`#1852 <https://github.com/ros-controls/ros2_control/pull/1852>`_).