[lwip-users] lwIP performance with FreeRTOS

[Chris Ponder]

Hi,

 

I am evaluating RTOS’s and IP stacks and have come across a strange result. I am using the ST32F207 G-EVAL board and ST have a ready-made package for the STM32F207 at http://www.st.com/internet/com/SOFTWARE_RESOURCES/SW_COMPONENT/FIRMWARE/stm32f2x7_eth_lwip.zip. This uses lwIP 1.3.2 and FreeRTOS 6.1.0.

 

I am evaluating single direction UDP packet send performance and so modified the standalone UDP echo client to send packets of just over 300 bytes repeatedly as fast as it could and clocked nearly 93Mbps average over 10 seconds using WireShark on Windows 7 to capture the packets.

 

I then switched to the FreeRTOS version of the echo client which contains TCP and UDP tasks. I disabled the TCP task and the pretty flashing LED task and replaced the echo code with the same code I used in the standalone version but using netconn and netbuf. The performance plummeted to barely over 36Mbps, nearly one third of the standalone performance.

 

The IAR compiler is set for high optimisation and speed. Are there any other performance metrics I should be tweaking such as #defines etc. The UDP task is at tskIDLE_PRIORITY + 3 and appears to be the only task that is now running, aside from lwIP itself.

 

Can anyone help?

 

Many thanks

 

Chris

********************************************************

The information transmitted is intended only for the person or entity to
which it is addressed and may contain confidential and/or privileged
material. If you are not the addressee, any disclosure, reproduction,
copying, distribution, or other dissemination or use of this communication is
strictly prohibited. If you have received this transmission in
error please notify the sender immediately and then delete this e-mail.
E-mail transmission cannot be guaranteed to be secure or error free as
information could be intercepted, corrupted lost, destroyed, arrive late or
incomplete, or contain viruses.
The sender therefore does not accept liability for any errors or omissions
in the contents of this message which arise as a result of e-mail
transmission. If verification is required please request a hard copy
version.

********************************************************