Can you provide some more information?

Actual timings, and a tcpdump fragment?

On 2/14/06, Laurent Lagrange [off-list ref] wrote:

Hi Pantelis,

Thanks for the express reply.

I know that what I say seems incredible. But I don't understand what NAPI
does.
My measure is very simple. I display a message on the client when 1000
exchanges are done.
I already check the ifconfig stats on the board after some seconds.
The measures seems the same with or without NAPI.

More details ?
Thanks again
Laurent



-----Message d'origine-----
*De :* Pantelis Antoniou [mailto:pantelis.antoniou@gmail.com]
*Envoyé :* mar. 14 février 2006 16:29
*À :* Laurent Lagrange
*Cc :* linuxppc-embedded@ozlabs.org
*Objet :* Re: Gianfar is slower than fcc_enet on MPC8541 ???

Hi Laurent,

I found that pretty hard to believe.

What are you measuring exactly?

Speed of replies? If so it's explainable since the TSECs use
NAPI.

Regards

Pantelis

On 2/14/06, Laurent Lagrange [off-list ref] wrote:

quoted

Hello,

I work on a cutom MPC8541 board with Linux 2.6.9.
The kernel activates the L1 cache (instructions and data)
and the L2 cache (entirely used as cache and not as sram).

I configure
1 FCC (FCC1),
2 TSECs with or without NAPI (no effect) but without stashing in L2
sram.
All PHYs are automatically configured in 100MB full duplex.

        eth0: Gianfar Ethernet Controller Version 1.1, 00:10:cd:48:48:e0
        eth0: Running with NAPI disabled
        eth0: 64/64 RX/TX BD ring size
        eth1: Gianfar Ethernet Controller Version 1.1, 00:10:cd:48:48:e1
        eth1: Running with NAPI disabled
        eth1: 64/64 RX/TX BD ring size
        eth2: FCC ENET Version custom, 00:10:cd:48:48:e2

Then I launch 3 simple TCP servers, one on each ports.

From remote machines I runs 3 TCP clients.
The client sends messages of 1000 bytes,
The server receives and echoes the message
The client receives the echoed message, check the content
and sends a new message again.

The result is that the 2 TSECs are 2 times slower than the FCC.

If I run a "top" application on the board, I use less than 10% of the
CPU
Each port consumes about 1/3 of the CPU.

Any idea on how to configure the gianfar driver ?

Thanks
Laurent


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