Re: [lwip-users] lwip whole performance down

[vincent cui]

Hi sylvailn and bill:

Thank you for your advise . 
Current, I can keep sending and reveiving speed stable by modify enthernet DMA 
data chain from 5 to 3. As I said that DMA data buffer become unvailable if set 
the value to 5.
But there is another problem, it maybe not performance issue . I am not sure.
After sending a large file, I close the connection and try to open connection 
again , I found that it takes a 1 or 2 seconds to open connect successfully .I 
use TCP&UDP test tool to do this .
I reduce task number to 3. They are TCPIP thread, Enthernet thread and test 
thread. I really have no idea why it will take so long to connect. 
I did same testing before system boot and don't send file, the connection time 
is short, almost no any delay ..

Anyone can explain this ?


-----Original Message-----
From: address@hidden [mailto:address@hidden On Behalf Of Sylvain Rochet
Sent: 2012年5月17日 1:09
To: Mailing list for lwIP users
Subject: Re: [lwip-users] lwip whole performance down

Hi,

On Wed, May 16, 2012 at 12:25:09PM -0400, Bill Auerbach wrote:
> 
> In my experience, most performance issues have been in my driver or 
> hardware platform, not in lwIP.  I don't use a real OS so I can't 
> speak to its added overhead.

Added to that, considering lwIP is working almost without lock (or just small 
one around memory allocation) and being totally non-blocking by the way it is 
designed should never be the reason of slowness over time.

DMA issues, interrupt issues, bus matrix overloading, etc, are in most cases 
the reason and obviously where to look first.

Sylvain