[dpdk-dev] [PATCH v2] app/testpmd: Document what the application does.

[dpdk-dev] [PATCH v2] app/testpmd: Document what the application does.

[Ben Pfaff]

I could not find anything in the documentation that says what
testpmd does.  This should save other people time trying to
figure that out in the future.

Signed-off-by: Ben Pfaff <blp@ovn.org>
---
v1->v2: Revise introduction instead of option documentation.
  Thanks to Thomas Monjalon for advice.

 doc/guides/testpmd_app_ug/intro.rst | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/doc/guides/testpmd_app_ug/intro.rst b/doc/guides/testpmd_app_ug/intro.rst
index 5d8d8cf4eb..1129f53c62 100644
--- a/doc/guides/testpmd_app_ug/intro.rst
+++ b/doc/guides/testpmd_app_ug/intro.rst
@@ -6,9 +6,13 @@ Introduction
 
 This document is a user guide for the ``testpmd`` example application that is shipped as part of the Data Plane Development Kit.
 
-The ``testpmd`` application can be used to test the DPDK in a packet forwarding mode
-and also to access NIC hardware features such as Flow Director.
-It also serves as a example of how to build a more fully-featured application using the DPDK SDK.
+``testpmd`` is a tool to test ethdev NIC features, including NIC
+hardware features such as Flow Director.  It receives packets on each
+configured port and forwards them.  By default, packets received on
+port 0 are forwarded to port 1, and vice versa, and similarly for
+ports 2 and 3, ports 4 and 5, and so on.  If an odd number of ports is
+configured, packets received on the last port are sent back out on the
+same port.
 
 The guide shows how to build and run the testpmd application and
 how to configure the application from the command line and the run-time environment.
-- 
2.31.1

Re: [dpdk-dev] [PATCH v2] app/testpmd: Document what the application does.

[Thomas Monjalon]

13/09/2021 20:33, Ben Pfaff:
> I could not find anything in the documentation that says what
> testpmd does.  This should save other people time trying to
> figure that out in the future.
> 
> Signed-off-by: Ben Pfaff <blp@ovn.org>
[...]
> --- a/doc/guides/testpmd_app_ug/intro.rst
> +++ b/doc/guides/testpmd_app_ug/intro.rst
> @@ -6,9 +6,13 @@ Introduction
>  
>  This document is a user guide for the ``testpmd`` example application that is shipped as part of the Data Plane Development Kit.
>  
> -The ``testpmd`` application can be used to test the DPDK in a packet forwarding mode
> -and also to access NIC hardware features such as Flow Director.
> -It also serves as a example of how to build a more fully-featured application using the DPDK SDK.
> +``testpmd`` is a tool to test ethdev NIC features, including NIC
> +hardware features such as Flow Director.  It receives packets on each

Not sure about keep mentioning Flow Director which is an Intel name
for an internal feature used through rte_flow rules.
What others think? Do we have better examples of hardware offload?

> +configured port and forwards them.  By default, packets received on
> +port 0 are forwarded to port 1, and vice versa, and similarly for
> +ports 2 and 3, ports 4 and 5, and so on.  If an odd number of ports is
> +configured, packets received on the last port are sent back out on the
> +same port.
>  
>  The guide shows how to build and run the testpmd application and
>  how to configure the application from the command line and the run-time environment.

Re: [dpdk-dev] [PATCH v2] app/testpmd: Document what the application does.

[Ajit Khaparde]

[-- Attachment #1: Type: text/plain, Size: 1804 bytes --]

On Mon, Sep 13, 2021 at 11:59 AM Thomas Monjalon <thomas@monjalon.net> wrote:
>
> 13/09/2021 20:33, Ben Pfaff:
> > I could not find anything in the documentation that says what
> > testpmd does.  This should save other people time trying to
> > figure that out in the future.
> >
> > Signed-off-by: Ben Pfaff <blp@ovn.org>
> [...]
> > --- a/doc/guides/testpmd_app_ug/intro.rst
> > +++ b/doc/guides/testpmd_app_ug/intro.rst
> > @@ -6,9 +6,13 @@ Introduction
> >
> >  This document is a user guide for the ``testpmd`` example application that is shipped as part of the Data Plane Development Kit.
> >
> > -The ``testpmd`` application can be used to test the DPDK in a packet forwarding mode
> > -and also to access NIC hardware features such as Flow Director.
> > -It also serves as a example of how to build a more fully-featured application using the DPDK SDK.
> > +``testpmd`` is a tool to test ethdev NIC features, including NIC
> > +hardware features such as Flow Director.  It receives packets on each
>
> Not sure about keep mentioning Flow Director which is an Intel name
> for an internal feature used through rte_flow rules.
> What others think? Do we have better examples of hardware offload?

We could use RSS and RFS.
I think Receive Side Scaling and Receive Flow Steering would cover the
intended offloads.

>
> > +configured port and forwards them.  By default, packets received on
> > +port 0 are forwarded to port 1, and vice versa, and similarly for
> > +ports 2 and 3, ports 4 and 5, and so on.  If an odd number of ports is
> > +configured, packets received on the last port are sent back out on the
> > +same port.
> >
> >  The guide shows how to build and run the testpmd application and
> >  how to configure the application from the command line and the run-time environment.
>
>
>

Re: [dpdk-dev] [PATCH v2] app/testpmd: Document what the application does.

[Ajit Khaparde]

[-- Attachment #1: Type: text/plain, Size: 2020 bytes --]

On Mon, Sep 13, 2021 at 5:26 PM Ajit Khaparde
<ajit.khaparde@broadcom.com> wrote:
>
> On Mon, Sep 13, 2021 at 11:59 AM Thomas Monjalon <thomas@monjalon.net> wrote:
> >
> > 13/09/2021 20:33, Ben Pfaff:
> > > I could not find anything in the documentation that says what
> > > testpmd does.  This should save other people time trying to
> > > figure that out in the future.
> > >
> > > Signed-off-by: Ben Pfaff <blp@ovn.org>
> > [...]
> > > --- a/doc/guides/testpmd_app_ug/intro.rst
> > > +++ b/doc/guides/testpmd_app_ug/intro.rst
> > > @@ -6,9 +6,13 @@ Introduction
> > >
> > >  This document is a user guide for the ``testpmd`` example application that is shipped as part of the Data Plane Development Kit.
> > >
> > > -The ``testpmd`` application can be used to test the DPDK in a packet forwarding mode
> > > -and also to access NIC hardware features such as Flow Director.
> > > -It also serves as a example of how to build a more fully-featured application using the DPDK SDK.
> > > +``testpmd`` is a tool to test ethdev NIC features, including NIC
> > > +hardware features such as Flow Director.  It receives packets on each
> >
> > Not sure about keep mentioning Flow Director which is an Intel name
> > for an internal feature used through rte_flow rules.
> > What others think? Do we have better examples of hardware offload?
>
> We could use RSS and RFS.
> I think Receive Side Scaling and Receive Flow Steering would cover the
> intended offloads.
I forgot to mention RPS - Receive Packet Steering.

>
> >
> > > +configured port and forwards them.  By default, packets received on
> > > +port 0 are forwarded to port 1, and vice versa, and similarly for
> > > +ports 2 and 3, ports 4 and 5, and so on.  If an odd number of ports is
> > > +configured, packets received on the last port are sent back out on the
> > > +same port.
> > >
> > >  The guide shows how to build and run the testpmd application and
> > >  how to configure the application from the command line and the run-time environment.
> >
> >
> >

Re: [dpdk-dev] [PATCH v2] app/testpmd: Document what the application does.

[Ferruh Yigit]

On 9/13/2021 7:33 PM, Ben Pfaff wrote:
> I could not find anything in the documentation that says what
> testpmd does.  This should save other people time trying to
> figure that out in the future.
> 
> Signed-off-by: Ben Pfaff <blp@ovn.org>
> ---
> v1->v2: Revise introduction instead of option documentation.
>   Thanks to Thomas Monjalon for advice.
> 
>  doc/guides/testpmd_app_ug/intro.rst | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/doc/guides/testpmd_app_ug/intro.rst b/doc/guides/testpmd_app_ug/intro.rst
> index 5d8d8cf4eb..1129f53c62 100644
> --- a/doc/guides/testpmd_app_ug/intro.rst
> +++ b/doc/guides/testpmd_app_ug/intro.rst
> @@ -6,9 +6,13 @@ Introduction
>  
>  This document is a user guide for the ``testpmd`` example application that is shipped as part of the Data Plane Development Kit.
>  
> -The ``testpmd`` application can be used to test the DPDK in a packet forwarding mode
> -and also to access NIC hardware features such as Flow Director.
> -It also serves as a example of how to build a more fully-featured application using the DPDK SDK.
> +``testpmd`` is a tool to test ethdev NIC features, including NIC
> +hardware features such as Flow Director.  It receives packets on each
> +configured port and forwards them.  By default, packets received on
> +port 0 are forwarded to port 1, and vice versa, and similarly for
> +ports 2 and 3, ports 4 and 5, and so on.  If an odd number of ports is
> +configured, packets received on the last port are sent back out on the
> +same port.
>  

Ahh, I missed that there is a v2, I already commented on the first version.

Just to summarize here, I think documenting a specific forwarding engine and
specific configuration of it as what 'testpmd' does can be misleading.

What about making it a little more generic and provide link for more details,
like: https://doc.dpdk.org/guides/testpmd_app_ug/testpmd_funcs.html#set-fwd



>  The guide shows how to build and run the testpmd application and
>  how to configure the application from the command line and the run-time environment.
>