[dpdk-dev] [PATCH v6 1/5] eventdev/rx_adapter: add event buffer size configurability

[Naga Harish K S V <s.v.naga.harish.k@intel.com>]

Currently event buffer is static array with a default size defined
internally.

To configure event buffer size from application,
``rte_event_eth_rx_adapter_create_with_params`` api is added which
takes ``struct rte_event_eth_rx_adapter_params`` to configure event
buffer size in addition other params . The event buffer size is
rounded up for better buffer utilization and performance . In case
of NULL params argument, default event buffer size is used.

Signed-off-by: Naga Harish K S V <s.v.naga.harish.k@intel.com>
Signed-off-by: Ganapati Kundapura <ganapati.kundapura@intel.com>

---
v6:
* address code style related review comments

v5:
* reverted queue conf get unit test change

v4:
* rebased with latest dpdk-next-eventdev branch
* changed queue conf get unit test

v3:
* updated documentation and code comments as per review comments.
* updated new create api test case name with suitable one.

v2:
* Updated header file and rx adapter documentation as per review comments.
* new api name is modified as rte_event_eth_rx_adapter_create_with_params
  as per review comments.
* rxa_params pointer argument Value NULL is allowed to represent the
  default values

v1:
* Initial implementation with documentation and unit tests.
---
---
 .../prog_guide/event_ethernet_rx_adapter.rst  |  7 ++
 lib/eventdev/rte_event_eth_rx_adapter.c       | 98 +++++++++++++++++--
 lib/eventdev/rte_event_eth_rx_adapter.h       | 41 +++++++-
 lib/eventdev/version.map                      |  2 +
 4 files changed, 140 insertions(+), 8 deletions(-)

diff --git a/doc/guides/prog_guide/event_ethernet_rx_adapter.rst b/doc/guides/prog_guide/event_ethernet_rx_adapter.rst
index ce23d8a474..8526aecf57 100644
--- a/doc/guides/prog_guide/event_ethernet_rx_adapter.rst
+++ b/doc/guides/prog_guide/event_ethernet_rx_adapter.rst
@@ -62,6 +62,13 @@ service function and needs to create an event port for it. The callback is
 expected to fill the ``struct rte_event_eth_rx_adapter_conf structure``
 passed to it.
 
+If the application desires to control the event buffer size, it can use the
+``rte_event_eth_rx_adapter_create_with_params()`` api. The event buffer size is
+specified using ``struct rte_event_eth_rx_adapter_params::event_buf_size``.
+The function is passed the event device to be associated with the adapter
+and port configuration for the adapter to setup an event port if the
+adapter needs to use a service function.
+
 Adding Rx Queues to the Adapter Instance
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/lib/eventdev/rte_event_eth_rx_adapter.c b/lib/eventdev/rte_event_eth_rx_adapter.c
index 10491ca07b..5ccea168ea 100644
--- a/lib/eventdev/rte_event_eth_rx_adapter.c
+++ b/lib/eventdev/rte_event_eth_rx_adapter.c
@@ -85,7 +85,9 @@ struct rte_eth_event_enqueue_buffer {
 	/* Count of events in this buffer */
 	uint16_t count;
 	/* Array of events in this buffer */
-	struct rte_event events[ETH_EVENT_BUFFER_SIZE];
+	struct rte_event *events;
+	/* size of event buffer */
+	uint16_t events_size;
 	/* Event enqueue happens from head */
 	uint16_t head;
 	/* New packets from rte_eth_rx_burst is enqued from tail */
@@ -946,7 +948,7 @@ rxa_buffer_mbufs(struct rte_event_eth_rx_adapter *rx_adapter,
 		dropped = 0;
 		nb_cb = dev_info->cb_fn(eth_dev_id, rx_queue_id,
 				       buf->last |
-				       (RTE_DIM(buf->events) & ~buf->last_mask),
+				       (buf->events_size & ~buf->last_mask),
 				       buf->count >= BATCH_SIZE ?
 						buf->count - BATCH_SIZE : 0,
 				       &buf->events[buf->tail],
@@ -972,7 +974,7 @@ rxa_pkt_buf_available(struct rte_eth_event_enqueue_buffer *buf)
 	uint32_t nb_req = buf->tail + BATCH_SIZE;
 
 	if (!buf->last) {
-		if (nb_req <= RTE_DIM(buf->events))
+		if (nb_req <= buf->events_size)
 			return true;
 
 		if (buf->head >= BATCH_SIZE) {
@@ -2206,12 +2208,15 @@ rxa_ctrl(uint8_t id, int start)
 	return 0;
 }
 
-int
-rte_event_eth_rx_adapter_create_ext(uint8_t id, uint8_t dev_id,
-				rte_event_eth_rx_adapter_conf_cb conf_cb,
-				void *conf_arg)
+static int
+rxa_create(uint8_t id, uint8_t dev_id,
+	   struct rte_event_eth_rx_adapter_params *rxa_params,
+	   rte_event_eth_rx_adapter_conf_cb conf_cb,
+	   void *conf_arg)
 {
 	struct rte_event_eth_rx_adapter *rx_adapter;
+	struct rte_eth_event_enqueue_buffer *buf;
+	struct rte_event *events;
 	int ret;
 	int socket_id;
 	uint16_t i;
@@ -2226,6 +2231,7 @@ rte_event_eth_rx_adapter_create_ext(uint8_t id, uint8_t dev_id,
 
 	RTE_EVENT_ETH_RX_ADAPTER_ID_VALID_OR_ERR_RET(id, -EINVAL);
 	RTE_EVENTDEV_VALID_DEVID_OR_ERR_RET(dev_id, -EINVAL);
+
 	if (conf_cb == NULL)
 		return -EINVAL;
 
@@ -2273,11 +2279,30 @@ rte_event_eth_rx_adapter_create_ext(uint8_t id, uint8_t dev_id,
 		rte_free(rx_adapter);
 		return -ENOMEM;
 	}
+
 	rte_spinlock_init(&rx_adapter->rx_lock);
+
 	for (i = 0; i < RTE_MAX_ETHPORTS; i++)
 		rx_adapter->eth_devices[i].dev = &rte_eth_devices[i];
 
+	/* Rx adapter event buffer allocation */
+	buf = &rx_adapter->event_enqueue_buffer;
+	buf->events_size = rxa_params->event_buf_size;
+
+	events = rte_zmalloc_socket(rx_adapter->mem_name,
+				    buf->events_size * sizeof(*events),
+				    0, socket_id);
+	if (events == NULL) {
+		RTE_EDEV_LOG_ERR("Failed to allocate mem for event buffer\n");
+		rte_free(rx_adapter->eth_devices);
+		rte_free(rx_adapter);
+		return -ENOMEM;
+	}
+
+	rx_adapter->event_enqueue_buffer.events = events;
+
 	event_eth_rx_adapter[id] = rx_adapter;
+
 	if (conf_cb == rxa_default_conf_cb)
 		rx_adapter->default_cb_arg = 1;
 
@@ -2293,6 +2318,61 @@ rte_event_eth_rx_adapter_create_ext(uint8_t id, uint8_t dev_id,
 	return 0;
 }
 
+int
+rte_event_eth_rx_adapter_create_ext(uint8_t id, uint8_t dev_id,
+				rte_event_eth_rx_adapter_conf_cb conf_cb,
+				void *conf_arg)
+{
+	struct rte_event_eth_rx_adapter_params rxa_params = {0};
+
+	/* use default values for adapter params */
+	rxa_params.event_buf_size = ETH_EVENT_BUFFER_SIZE;
+
+	return rxa_create(id, dev_id, &rxa_params, conf_cb, conf_arg);
+}
+
+int
+rte_event_eth_rx_adapter_create_with_params(uint8_t id, uint8_t dev_id,
+			struct rte_event_port_conf *port_config,
+			struct rte_event_eth_rx_adapter_params *rxa_params)
+{
+	struct rte_event_port_conf *pc;
+	int ret;
+	struct rte_event_eth_rx_adapter_params temp_params = {0};
+
+	if (port_config == NULL)
+		return -EINVAL;
+
+	/* use default values if rxa_params is NULL */
+	if (rxa_params == NULL) {
+		rxa_params = &temp_params;
+		rxa_params->event_buf_size = ETH_EVENT_BUFFER_SIZE;
+	}
+
+	if (rxa_params->event_buf_size == 0)
+		return -EINVAL;
+
+	pc = rte_malloc(NULL, sizeof(*pc), 0);
+	if (pc == NULL)
+		return -ENOMEM;
+
+	*pc = *port_config;
+
+	/* adjust event buff size with BATCH_SIZE used for fetching packets
+	 * from NIC rx queues to get full buffer utilization and prevent
+	 * unnecessary rollovers.
+	 */
+	rxa_params->event_buf_size = RTE_ALIGN(rxa_params->event_buf_size,
+					       BATCH_SIZE);
+	rxa_params->event_buf_size += (BATCH_SIZE + BATCH_SIZE);
+
+	ret = rxa_create(id, dev_id, rxa_params, rxa_default_conf_cb, pc);
+	if (ret)
+		rte_free(pc);
+
+	return ret;
+}
+
 int
 rte_event_eth_rx_adapter_create(uint8_t id, uint8_t dev_id,
 		struct rte_event_port_conf *port_config)
@@ -2302,12 +2382,14 @@ rte_event_eth_rx_adapter_create(uint8_t id, uint8_t dev_id,
 
 	if (port_config == NULL)
 		return -EINVAL;
+
 	RTE_EVENT_ETH_RX_ADAPTER_ID_VALID_OR_ERR_RET(id, -EINVAL);
 
 	pc = rte_malloc(NULL, sizeof(*pc), 0);
 	if (pc == NULL)
 		return -ENOMEM;
 	*pc = *port_config;
+
 	ret = rte_event_eth_rx_adapter_create_ext(id, dev_id,
 					rxa_default_conf_cb,
 					pc);
@@ -2336,6 +2418,7 @@ rte_event_eth_rx_adapter_free(uint8_t id)
 	if (rx_adapter->default_cb_arg)
 		rte_free(rx_adapter->conf_arg);
 	rte_free(rx_adapter->eth_devices);
+	rte_free(rx_adapter->event_enqueue_buffer.events);
 	rte_free(rx_adapter);
 	event_eth_rx_adapter[id] = NULL;
 
@@ -2711,6 +2794,7 @@ rte_event_eth_rx_adapter_stats_get(uint8_t id,
 
 	stats->rx_packets += dev_stats_sum.rx_packets;
 	stats->rx_enq_count += dev_stats_sum.rx_enq_count;
+
 	return 0;
 }
 
diff --git a/lib/eventdev/rte_event_eth_rx_adapter.h b/lib/eventdev/rte_event_eth_rx_adapter.h
index 470543e434..846ca569e9 100644
--- a/lib/eventdev/rte_event_eth_rx_adapter.h
+++ b/lib/eventdev/rte_event_eth_rx_adapter.h
@@ -26,6 +26,7 @@
  * The ethernet Rx event adapter's functions are:
  *  - rte_event_eth_rx_adapter_create_ext()
  *  - rte_event_eth_rx_adapter_create()
+ *  - rte_event_eth_rx_adapter_create_with_params()
  *  - rte_event_eth_rx_adapter_free()
  *  - rte_event_eth_rx_adapter_queue_add()
  *  - rte_event_eth_rx_adapter_queue_del()
@@ -37,7 +38,7 @@
  *
  * The application creates an ethernet to event adapter using
  * rte_event_eth_rx_adapter_create_ext() or rte_event_eth_rx_adapter_create()
- * functions.
+ * or rte_event_eth_rx_adapter_create_with_params() functions.
  * The adapter needs to know which ethernet rx queues to poll for mbufs as well
  * as event device parameters such as the event queue identifier, event
  * priority and scheduling type that the adapter should use when constructing
@@ -257,6 +258,17 @@ struct rte_event_eth_rx_adapter_vector_limits {
 	 */
 };
 
+/**
+ * A structure to hold adapter config params
+ */
+struct rte_event_eth_rx_adapter_params {
+	uint16_t event_buf_size;
+	/**< size of event buffer for the adapter.
+	 * This value is rounded up for better buffer utilization
+	 * and performance.
+	 */
+};
+
 /**
  *
  * Callback function invoked by the SW adapter before it continues
@@ -357,6 +369,33 @@ int rte_event_eth_rx_adapter_create_ext(uint8_t id, uint8_t dev_id,
 int rte_event_eth_rx_adapter_create(uint8_t id, uint8_t dev_id,
 				struct rte_event_port_conf *port_config);
 
+/**
+ * This is a variant of rte_event_eth_rx_adapter_create() with additional
+ * adapter params specified in ``struct rte_event_eth_rx_adapter_params``.
+ *
+ * @param id
+ *  The identifier of the ethernet Rx event adapter.
+ *
+ * @param dev_id
+ *  The identifier of the event device to configure.
+ *
+ * @param port_config
+ *  Argument of type *rte_event_port_conf* that is passed to the conf_cb
+ *  function.
+ *
+ * @param rxa_params
+ *  Pointer to struct rte_event_eth_rx_adapter_params.
+ *  In case of NULL, default values are used.
+ *
+ * @return
+ *   - 0: Success
+ *   - <0: Error code on failure
+ */
+__rte_experimental
+int rte_event_eth_rx_adapter_create_with_params(uint8_t id, uint8_t dev_id,
+			struct rte_event_port_conf *port_config,
+			struct rte_event_eth_rx_adapter_params *rxa_params);
+
 /**
  * Free an event adapter
  *
diff --git a/lib/eventdev/version.map b/lib/eventdev/version.map
index 9f280160fa..7de18497a6 100644
--- a/lib/eventdev/version.map
+++ b/lib/eventdev/version.map
@@ -138,6 +138,8 @@ EXPERIMENTAL {
 	__rte_eventdev_trace_port_setup;
 	# added in 20.11
 	rte_event_pmd_pci_probe_named;
+	# added in 21.11
+	rte_event_eth_rx_adapter_create_with_params;
 
 	#added in 21.05
 	rte_event_vector_pool_create;
-- 
2.25.1