doc: remove references to make from eventdevs guide

[dpdk.git] / doc / guides / prog_guide / event_ethernet_rx_adapter.rst

diff --git a/doc/guides/prog_guide/event_ethernet_rx_adapter.rst b/doc/guides/prog_guide/event_ethernet_rx_adapter.rst
index 319e4f0..236f43f 100644 (file)
--- a/doc/guides/prog_guide/event_ethernet_rx_adapter.rst
+++ b/doc/guides/prog_guide/event_ethernet_rx_adapter.rst
@@ -135,6 +135,11 @@ This function calls the start callbacks of the eventdev PMDs for hardware based
 eventdev-ethdev connections and ``rte_service_run_state_set()`` to enable the
 service function if one exists.
 
+.. Note::
+
+         The eventdev to which the event_eth_rx_adapter is connected needs to
+         be started before calling rte_event_eth_rx_adapter_start().
+
 Getting Adapter Statistics
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -144,3 +149,44 @@ enqueued event counts are a sum of the counts from the eventdev PMD callbacks
 if the callback is supported, and the counts maintained by the service function,
 if one exists. The service function also maintains a count of cycles for which
 it was not able to enqueue to the event device.
+
+Interrupt Based Rx Queues
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The service core function is typically set up to poll ethernet Rx queues for
+packets. Certain queues may have low packet rates and it would be more
+efficient to enable the Rx queue interrupt and read packets after receiving
+the interrupt.
+
+The servicing_weight member of struct rte_event_eth_rx_adapter_queue_conf
+is applicable when the adapter uses a service core function. The application
+has to enable Rx queue interrupts when configuring the ethernet device
+using the ``rte_eth_dev_configure()`` function and then use a servicing_weight
+of zero when adding the Rx queue to the adapter.
+
+The adapter creates a thread blocked on the interrupt, on an interrupt this
+thread enqueues the port id and the queue id to a ring buffer. The adapter
+service function dequeues the port id and queue id from the ring buffer,
+invokes the ``rte_eth_rx_burst()`` to receive packets on the queue and
+converts the received packets to events in the same manner as packets
+received on a polled Rx queue. The interrupt thread is affinitized to the same
+CPUs as the lcores of the Rx adapter service function, if the Rx adapter
+service function has not been mapped to any lcores, the interrupt thread
+is mapped to the main lcore.
+
+Rx Callback for SW Rx Adapter
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+For SW based packet transfers, i.e., when the
+``RTE_EVENT_ETH_RX_ADAPTER_CAP_INTERNAL_PORT`` is not set in the adapter's
+capabilities flags for a particular ethernet device, the service function
+temporarily enqueues mbufs to an event buffer before batch enqueuing these
+to the event device. If the buffer fills up, the service function stops
+dequeuing packets from the ethernet device. The application may want to
+monitor the buffer fill level and instruct the service function to selectively
+enqueue packets to the event device. The application may also use some other
+criteria to decide which packets should enter the event device even when
+the event buffer fill level is low. The
+``rte_event_eth_rx_adapter_cb_register()`` function allow the application
+to register a callback that selects which packets to enqueue to the event
+device.