Update graph documentation to introduce new multicore dispatch model. Signed-off-by: Haiyue Wang <haiyue.w...@intel.com> Signed-off-by: Cunming Liang <cunming.li...@intel.com> Signed-off-by: Zhirun Yan <zhirun....@intel.com> --- doc/guides/prog_guide/graph_lib.rst | 59 +++++++++++++++++++++++++++-- 1 file changed, 55 insertions(+), 4 deletions(-)
diff --git a/doc/guides/prog_guide/graph_lib.rst b/doc/guides/prog_guide/graph_lib.rst index 1cfdc86433..72e26f3a5a 100644 --- a/doc/guides/prog_guide/graph_lib.rst +++ b/doc/guides/prog_guide/graph_lib.rst @@ -189,14 +189,65 @@ In the above example, A graph object will be created with ethdev Rx node of port 0 and queue 0, all ipv4* nodes in the system, and ethdev tx node of all ports. -Multicore graph processing -~~~~~~~~~~~~~~~~~~~~~~~~~~ -In the current graph library implementation, specifically, -``rte_graph_walk()`` and ``rte_node_enqueue*`` fast path API functions +graph model chossing +~~~~~~~~~~~~~~~~~~~~ +Currently, there are 2 different walking model. Use +``rte_graph_worker_model_set()`` to set the walking model. + +RTC (Run-To-Completion) +^^^^^^^^^^^^^^^^^^^^^^^ +This is the default graph walking model. specifically, +``rte_graph_walk_rtc()`` and ``rte_node_enqueue*`` fast path API functions are designed to work on single-core to have better performance. The fast path API works on graph object, So the multi-core graph processing strategy would be to create graph object PER WORKER. +Example: + +Graph: node-0 -> node-1 -> node-2 @Core0. + +.. code-block:: diff + + + - - - - - - - - - - - - - - - - - - - - - + + ' Core #0 ' + ' ' + ' +--------+ +---------+ +--------+ ' + ' | Node-0 | --> | Node-1 | --> | Node-2 | ' + ' +--------+ +---------+ +--------+ ' + ' ' + + - - - - - - - - - - - - - - - - - - - - - + + +Dispatch model +^^^^^^^^^^^^^^ +The dispatch model enables a cross-core dispatching mechanism which employs +a scheduling work-queue to dispatch streams to other worker cores which +being associated with the destination node. + +Use ``rte_graph_model_dispatch_lcore_affinity_set()`` to set lcore affinity +with the node. +Each worker core will have a graph repetition. Use ``rte_graph_clone()`` to +clone graph for each worker and use``rte_graph_model_dispatch_core_bind()`` +to bind graph with the worker core. + +Example: + +Graph topo: node-0 -> Core1; node-1 -> node-2; node-2 -> node-3. +Config graph: node-0 @Core0; node-1/3 @Core1; node-2 @Core2. + +.. code-block:: diff + + + - - - - - -+ +- - - - - - - - - - - - - + + - - - - - -+ + ' Core #0 ' ' Core #1 ' ' Core #2 ' + ' ' ' ' ' ' + ' +--------+ ' ' +--------+ +--------+ ' ' +--------+ ' + ' | Node-0 | - - - ->| Node-1 | | Node-3 |<- - - - | Node-2 | ' + ' +--------+ ' ' +--------+ +--------+ ' ' +--------+ ' + ' ' ' | ' ' ^ ' + + - - - - - -+ +- - -|- - - - - - - - - - + + - - -|- - -+ + | | + + - - - - - - - - - - - - - - - - + + + In fast path ~~~~~~~~~~~~ Typical fast-path code looks like below, where the application -- 2.37.2
