[11/11] doc: update l3fwd user guide to support eventdev
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Commit Message
From: Sunil Kumar Kori <skori@marvell.com>
Update l3fwd user guide to include event device related information.
Signed-off-by: Sunil Kumar Kori <skori@marvell.com>
---
doc/guides/sample_app_ug/l3_forward.rst | 76 +++++++++++++++++++++++--
1 file changed, 70 insertions(+), 6 deletions(-)
@@ -4,16 +4,23 @@
L3 Forwarding Sample Application
================================
-The L3 Forwarding application is a simple example of packet processing using the DPDK.
+The L3 Forwarding application is a simple example of packet processing using
+DPDK to demonstrate usage of poll and event mode packet I/O mechanism.
The application performs L3 forwarding.
Overview
--------
-The application demonstrates the use of the hash and LPM libraries in the DPDK to implement packet forwarding.
-The initialization and run-time paths are very similar to those of the :doc:`l2_forward_real_virtual`.
-The main difference from the L2 Forwarding sample application is that the forwarding decision
-is made based on information read from the input packet.
+The application demonstrates the use of the hash and LPM libraries in the DPDK
+to implement packet forwarding using poll or event mode PMDs for packet I/O.
+The initialization and run-time paths are very similar to those of the
+:doc:`l2_forward_real_virtual` and :doc:`l2_forward_event_real_virtual`.
+The main difference from the L2 Forwarding sample application is that optionally
+packet can be Rx/Tx from/to eventdev instead of port directly and forwarding
+decision is made based on information read from the input packet.
+
+Eventdev can optionally use S/W or H/W (if supported by platform) scheduler
+implementation for packet I/O based on run time parameters.
The lookup method is either hash-based or LPM-based and is selected at run time. When the selected lookup method is hash-based,
a hash object is used to emulate the flow classification stage.
@@ -56,6 +63,8 @@ The application has a number of command line options::
[--ipv6]
[--parse-ptype]
[--per-port-pool]
+ [--mode]
+ [--eventq-sync]
Where,
@@ -86,6 +95,11 @@ Where,
* ``--per-port-pool:`` Optional, set to use independent buffer pools per port. Without this option, single buffer pool is used for all ports.
+* ``--mode:`` Optional, Packet transfer mode for I/O, poll or eventdev.
+
+* ``--eventq-sync:`` Optional, Event queue synchronization method, Ordered or Atomic. Only valid if --mode=eventdev.
+
+
For example, consider a dual processor socket platform with 8 physical cores, where cores 0-7 and 16-23 appear on socket 0,
while cores 8-15 and 24-31 appear on socket 1.
@@ -116,6 +130,51 @@ In this command:
| | | | |
+----------+-----------+-----------+-------------------------------------+
+To use eventdev mode with sync method **ordered** on above mentioned environment,
+Following is the sample command:
+
+.. code-block:: console
+
+ ./build/l3fwd -l 0-3 -n 4 -w <event device> -- -p 0x3 --eventq-sync=ordered
+
+or
+
+.. code-block:: console
+
+ ./build/l3fwd -l 0-3 -n 4 -w <event device> -- -p 0x03 --mode=eventdev --eventq-sync=ordered
+
+In this command:
+
+* -w option whitelist the event device supported by platform. Way to pass this device may vary based on platform.
+
+* The --mode option defines PMD to be used for packet I/O.
+
+* The --eventq-sync option enables synchronization menthod of event queue so that packets will be scheduled accordingly.
+
+If application uses S/W scheduler, it uses following DPDK services:
+
+* Software scheduler
+* Rx adapter service function
+* Tx adapter service function
+
+Application needs service cores to run above mentioned services. Service cores
+must be provided as EAL parameters along with the --vdev=event_sw0 to enable S/W
+scheduler. Following is the sample command:
+
+.. code-block:: console
+
+ ./build/l3fwd -l 0-7 -s 0-3 -n 4 --vdev event_sw0 -- -p 0x3 --mode=eventdev --eventq-sync=ordered
+
+In case of eventdev mode, *--config* option is not used for ethernet port
+configuration. Instead each ethernet port will be configured with mentioned
+setup:
+
+* Single Rx/Tx queue
+
+* Each Rx queue will be connected to event queue via Rx adapter.
+
+* Each Tx queue will be connected via Tx adapter.
+
Refer to the *DPDK Getting Started Guide* for general information on running applications and
the Environment Abstraction Layer (EAL) options.
@@ -125,7 +184,7 @@ Explanation
-----------
The following sections provide some explanation of the sample application code. As mentioned in the overview section,
-the initialization and run-time paths are very similar to those of the :doc:`l2_forward_real_virtual`.
+the initialization and run-time paths are very similar to those of the :doc:`l2_forward_real_virtual` and :doc:`l2_forward_event_real_virtual`.
The following sections describe aspects that are specific to the L3 Forwarding sample application.
Hash Initialization
@@ -315,3 +374,8 @@ for LPM-based lookups is done by the get_ipv4_dst_port() function below:
return ((rte_lpm_lookup(ipv4_l3fwd_lookup_struct, rte_be_to_cpu_32(ipv4_hdr->dst_addr), &next_hop) == 0)? next_hop : portid);
}
+
+Eventdev Driver Initialization
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Eventdev driver initialization is same as L2 forwarding eventdev application.
+Refer :doc:`l2_forward_event_real_virtual` for more details.