master_doc = 'index'
+# Maximum feature description string length
+feature_str_len = 25
+
# Figures, tables and code-blocks automatically numbered if they have caption
numfig = True
def print_table_row(outfile, feature, line):
""" Print a single row of the table with fixed formatting. """
line = line.rstrip()
- print(' {:<20}{}'.format(feature, line), file=outfile)
+ print(' {:<{}}{}'.format(feature, feature_str_len, line), file=outfile)
def print_table_divider(outfile, num_cols):
column_dividers = ['='] * num_cols
line += ' '.join(column_dividers)
- feature = '=' * 20
+ feature = '=' * feature_str_len
print_table_row(outfile, feature, line)
;
; This file defines the features that are valid for inclusion in
; the other driver files and also the order that they appear in
-; the features table in the documentation.
+; the features table in the documentation. The feature description
+; string should not exceed feature_str_len defined in conf.py.
;
[Features]
Speed capabilities =
Link status event =
Queue status event =
Rx interrupt =
+Free Tx mbuf on demand =
Queue start/stop =
MTU update =
Jumbo frame =
When configuring for DCB operation, at port initialization, both the number of transmit queues and the number of receive queues must be set to 128.
+Free Tx mbuf on Demand
+~~~~~~~~~~~~~~~~~~~~~~
+
+Many of the drivers do not release the mbuf back to the mempool, or local cache,
+immediately after the packet has been transmitted.
+Instead, they leave the mbuf in their Tx ring and
+either perform a bulk release when the ``tx_rs_thresh`` has been crossed
+or free the mbuf when a slot in the Tx ring is needed.
+
+An application can request the driver to release used mbufs with the ``rte_eth_tx_done_cleanup()`` API.
+This API requests the driver to release mbufs that are no longer in use,
+independent of whether or not the ``tx_rs_thresh`` has been crossed.
+There are two scenarios when an application may want the mbuf released immediately:
+
+* When a given packet needs to be sent to multiple destination interfaces
+ (either for Layer 2 flooding or Layer 3 multi-cast).
+ One option is to make a copy of the packet or a copy of the header portion that needs to be manipulated.
+ A second option is to transmit the packet and then poll the ``rte_eth_tx_done_cleanup()`` API
+ until the reference count on the packet is decremented.
+ Then the same packet can be transmitted to the next destination interface.
+ The application is still responsible for managing any packet manipulations needed
+ between the different destination interfaces, but a packet copy can be avoided.
+ This API is independent of whether the packet was transmitted or dropped,
+ only that the mbuf is no longer in use by the interface.
+
+* Some applications are designed to make multiple runs, like a packet generator.
+ For performance reasons and consistency between runs,
+ the application may want to reset back to an initial state
+ between each run, where all mbufs are returned to the mempool.
+ In this case, it can call the ``rte_eth_tx_done_cleanup()`` API
+ for each destination interface it has been using
+ to request it to release of all its used mbufs.
+
+To determine if a driver supports this API, check for the *Free Tx mbuf on demand* feature
+in the *Network Interface Controller Drivers* document.
+
Hardware Offload
~~~~~~~~~~~~~~~~
Also, make sure to start the actual text at the margin.
=========================================================
+* **Added free Tx mbuf on demand API.**
+
+ Added a new function ``rte_eth_tx_done_cleanup()`` which allows an application
+ to request the driver to release mbufs from their Tx ring that are no longer
+ in use, independent of whether or not the ``tx_rs_thresh`` has been crossed.
+
* **Increased number of next hops for LPM IPv6 to 2^21.**
The next_hop field is extended from 8 bits to 21 bits for IPv6.
sPAPR IOMMU based pci probing enabled for vfio-pci devices.
+
Resolved Issues
---------------
return ret;
}
+int
+rte_eth_tx_done_cleanup(uint8_t port_id, uint16_t queue_id, uint32_t free_cnt)
+{
+ struct rte_eth_dev *dev = &rte_eth_devices[port_id];
+
+ /* Validate Input Data. Bail if not valid or not supported. */
+ RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
+ RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->tx_done_cleanup, -ENOTSUP);
+
+ /* Call driver to free pending mbufs. */
+ return (*dev->dev_ops->tx_done_cleanup)(dev->data->tx_queues[queue_id],
+ free_cnt);
+}
+
void
rte_eth_promiscuous_enable(uint8_t port_id)
{
char *fw_version, size_t fw_size);
/**< @internal Get firmware information of an Ethernet device. */
+typedef int (*eth_tx_done_cleanup_t)(void *txq, uint32_t free_cnt);
+/**< @internal Force mbufs to be from TX ring. */
+
typedef void (*eth_rxq_info_get_t)(struct rte_eth_dev *dev,
uint16_t rx_queue_id, struct rte_eth_rxq_info *qinfo);
eth_rx_disable_intr_t rx_queue_intr_disable; /**< Disable Rx queue interrupt. */
eth_tx_queue_setup_t tx_queue_setup;/**< Set up device TX queue. */
eth_queue_release_t tx_queue_release; /**< Release TX queue. */
+ eth_tx_done_cleanup_t tx_done_cleanup;/**< Free tx ring mbufs */
eth_dev_led_on_t dev_led_on; /**< Turn on LED. */
eth_dev_led_off_t dev_led_off; /**< Turn off LED. */
rte_eth_tx_buffer_count_callback(struct rte_mbuf **pkts, uint16_t unsent,
void *userdata);
+/**
+ * Request the driver to free mbufs currently cached by the driver. The
+ * driver will only free the mbuf if it is no longer in use. It is the
+ * application's responsibity to ensure rte_eth_tx_buffer_flush(..) is
+ * called if needed.
+ *
+ * @param port_id
+ * The port identifier of the Ethernet device.
+ * @param queue_id
+ * The index of the transmit queue through which output packets must be
+ * sent.
+ * The value must be in the range [0, nb_tx_queue - 1] previously supplied
+ * to rte_eth_dev_configure().
+ * @param free_cnt
+ * Maximum number of packets to free. Use 0 to indicate all possible packets
+ * should be freed. Note that a packet may be using multiple mbufs.
+ * @return
+ * Failure: < 0
+ * -ENODEV: Invalid interface
+ * -ENOTSUP: Driver does not support function
+ * Success: >= 0
+ * 0-n: Number of packets freed. More packets may still remain in ring that
+ * are in use.
+ */
+int
+rte_eth_tx_done_cleanup(uint8_t port_id, uint16_t queue_id, uint32_t free_cnt);
+
/**
* The eth device event type for interrupt, and maybe others in the future.
*/
git.droids-corp.org / dpdk.git / commitdiff