RE: [PATCH] doc: add cnxk dmadev performance tuning details

[Vamsi Krishna Attunuru <vattunuru@marvell.com>]

Acked-by:  Vamsi Krishna Attunuru <vattunuru@marvell.com>

> -----Original Message-----
> From: Amit Prakash Shukla <amitprakashs@marvell.com>
> Sent: Friday, September 29, 2023 7:19 PM
> To: Vamsi Krishna Attunuru <vattunuru@marvell.com>
> Cc: dev@dpdk.org; Jerin Jacob Kollanukkaran <jerinj@marvell.com>; Amit
> Prakash Shukla <amitprakashs@marvell.com>
> Subject: [PATCH] doc: add cnxk dmadev performance tuning details
> 
> Updated cnxk DMA driver document to explain about performance tuning
> parameters for kernel module.
> 
> Signed-off-by: Amit Prakash Shukla <amitprakashs@marvell.com>
> ---
>  doc/guides/dmadevs/cnxk.rst | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/doc/guides/dmadevs/cnxk.rst b/doc/guides/dmadevs/cnxk.rst
> index 418b9a9d63..8d841b1f12 100644
> --- a/doc/guides/dmadevs/cnxk.rst
> +++ b/doc/guides/dmadevs/cnxk.rst
> @@ -56,3 +56,33 @@ Performing Data Copies  Refer to the :ref:`Enqueue /
> Dequeue APIs <dmadev_enqueue_dequeue>` section  of the dmadev
> library documentation  for details on operation enqueue and submission API
> usage.
> +
> +Performance Tuning Parameters
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +To achieve higher performance, DMA device needs to be tuned using PF
> +kernel driver module params. The PF kernel driver is part of the octeon
> +sdk. Module params shall be configured during module insert as in below
> example::
> +
> +    $ sudo insmod octeontx2_dpi.ko mps=128 mrrs=128
> + eng_fifo_buf=0x101008080808
> +
> +* ``mps``
> +  Maximum payload size. MPS size shall not exceed the size selected by PCI
> config.
> +  Max size that shall be configured can be found on executing ``lspci``
> +command
> +  for the device.
> +
> +* ``mrrs``
> +  Maximum read request size. MRRS size shall not exceed the size
> +selected by PCI
> +  config. Max size that shall be configured can be found on executing
> +``lspci``
> +  command for the device.
> +
> +* ``eng_fifo_buf``
> +  CNXK supports 6 DMA engines and each engine has an associated FIFO.
> +By-default
> +  all engine's FIFO is configured to 8 KB. Engine FIFO size can be
> +tuned using this
> +  64 bit variable, where each byte represents an engine. In the example
> +above engine
> +  0-3 FIFO are configure as 8 KB and engine 4-5 are configured as 16 KB.
> +
> +.. note::
> +    MPS and MRRS performance tuning parameters helps achieve higher
> performance
> +    only for Inbound and Outbound DMA transfers. The parameter has no
> effect for
> +    Internal only DMA transfer.
> --
> 2.25.1