From 55499896d91a4fb01e743b71df639dc1c18314d8 Mon Sep 17 00:00:00 2001 From: Pavan Nikhilesh Date: Tue, 28 Jan 2020 11:05:05 +0530 Subject: [PATCH] doc: add event mode to l3fwd guide Update l3fwd user guide to include event device related information. Update release notes. Signed-off-by: Pavan Nikhilesh Acked-by: Jerin Jacob --- doc/guides/rel_notes/release_20_02.rst | 5 ++ doc/guides/sample_app_ug/l3_forward.rst | 79 +++++++++++++++++++++++-- 2 files changed, 78 insertions(+), 6 deletions(-) diff --git a/doc/guides/rel_notes/release_20_02.rst b/doc/guides/rel_notes/release_20_02.rst index 50e2c14841..a601d18b00 100644 --- a/doc/guides/rel_notes/release_20_02.rst +++ b/doc/guides/rel_notes/release_20_02.rst @@ -143,6 +143,11 @@ New Features Added a new OCTEON TX2 rawdev PMD for End Point mode of operation. See the :doc:`../rawdevs/octeontx2_ep` for more details on this new PMD. +* **Added event mode to l3fwd sample application.** + + Add event device support for ``l3fwd`` sample application. It demonstrates + usage of poll and event mode IO mechanism under a single application. + Removed Items ------------- diff --git a/doc/guides/sample_app_ug/l3_forward.rst b/doc/guides/sample_app_ug/l3_forward.rst index 4cb4b18dab..153e46893a 100644 --- a/doc/guides/sample_app_ug/l3_forward.rst +++ b/doc/guides/sample_app_ug/l3_forward.rst @@ -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`. +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 +63,9 @@ The application has a number of command line options:: [--ipv6] [--parse-ptype] [--per-port-pool] + [--mode] + [--eventq-sched] + [--event-eth-rxqs] Where, @@ -86,6 +96,13 @@ 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-sched:`` Optional, Event queue synchronization method, Ordered, Atomic or Parallel. Only valid if --mode=eventdev. + +* ``--event-eth-rxqs:`` Optional, Number of ethernet RX queues per device. 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 +133,51 @@ 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 -- -p 0x3 --eventq-sched=ordered + +or + +.. code-block:: console + + ./build/l3fwd -l 0-3 -n 4 -w -- -p 0x03 --mode=eventdev --eventq-sched=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-sched 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-sched=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 +187,7 @@ 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`. The following sections describe aspects that are specific to the L3 Forwarding sample application. Hash Initialization @@ -315,3 +377,8 @@ 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` for more details. -- 2.20.1