[v6,15/15] doc: update multicore dispatch model in graph guides
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Commit Message
Update graph documentation to introduce new multicore dispatch model.
Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Signed-off-by: Cunming Liang <cunming.liang@intel.com>
Signed-off-by: Zhirun Yan <zhirun.yan@intel.com>
---
doc/guides/prog_guide/graph_lib.rst | 59 +++++++++++++++++++++++++++--
1 file changed, 55 insertions(+), 4 deletions(-)
Comments
On Tue, May 9, 2023 at 11:35 AM Zhirun Yan <zhirun.yan@intel.com> wrote:
>
> Update graph documentation to introduce new multicore dispatch model.
>
> Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
> Signed-off-by: Cunming Liang <cunming.liang@intel.com>
> Signed-off-by: Zhirun Yan <zhirun.yan@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
Graph models
> +~~~~~~~~~~~~~~~~~~~~
> +Currently, there are 2 different walking model. Use
model -> models
> -----Original Message-----
> From: Jerin Jacob <jerinjacobk@gmail.com>
> Sent: Wednesday, May 24, 2023 4:13 PM
> To: Yan, Zhirun <zhirun.yan@intel.com>
> Cc: dev@dpdk.org; jerinj@marvell.com; kirankumark@marvell.com;
> ndabilpuram@marvell.com; stephen@networkplumber.org;
> pbhagavatula@marvell.com; Liang, Cunming <cunming.liang@intel.com>; Wang,
> Haiyue <haiyue.wang@intel.com>
> Subject: Re: [PATCH v6 15/15] doc: update multicore dispatch model in graph
> guides
>
> On Tue, May 9, 2023 at 11:35 AM Zhirun Yan <zhirun.yan@intel.com> wrote:
> >
> > Update graph documentation to introduce new multicore dispatch model.
> >
> > Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
> > Signed-off-by: Cunming Liang <cunming.liang@intel.com>
> > Signed-off-by: Zhirun Yan <zhirun.yan@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
>
> Graph models
>
>
> > +~~~~~~~~~~~~~~~~~~~~
> > +Currently, there are 2 different walking model. Use
>
> model -> models
Got it. Thanks.
@@ -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