Ok.  Than as Simon pointed out - the tcp_output avoids Nagle.  I followed
the contrib/apps httpd example and without tcp_output calls I needed
TF_NODELAY.

 

Which is right?  I would hope that an lwIP contrib example would show the
correct way to implement something.

 

Bill

 

From: [email protected]
[mailto:[email protected]] On Behalf
Of Rick Culver
Sent: Friday, April 24, 2009 10:08 AM
To: Bill Auerbach; 'Mailing list for lwIP users'
Subject: Re: [lwip-users] httpd slow response

 

Bill,
I will try this in the accept call back and advise the results.  The httpd.c
module we are using is one that was supplied by Luminary Micro with their
function library.  It was modified from the one provided in contrib/apps to
include some SSI functionality (which we have disabled).  Basically the
"send_data" function includes a call to tcp_output() just before the final
return if any data was sent.

Rick

 

----- Original Message ----- 

From: Bill Auerbach <mailto:[email protected]>  

To: 'Rick <mailto:[email protected]>  Culver' ; 'Mailing list for
lwIP users' <mailto:[email protected]>  

Sent: Friday, April 24, 2009 7:41 AM

Subject: RE: [lwip-users] httpd slow response

 

Rick,

 

I did this in the accept callback.  I haven't seen an lwipopts method to do
this.  Which httpd server?  The one in lwIP contrib/apps doesn't have the
tcp_output you mention.

 

Bill.

 

From: [email protected]
[mailto:[email protected]] On Behalf
Of Rick Culver
Sent: Friday, April 24, 2009 8:23 AM
To: Bill Auerbach; 'Mailing list for lwIP users'
Subject: Re: [lwip-users] httpd slow response

 

Bill,

Thanks for the prompt response.  That would make sense to me.  Where/how
would I include this in the code?  Do you know if there is a way to change
this in the lwipopt.h file?  I do see that the httpd server does include the
tcp_output() function write after a tcp_write(), would that not negate the
nagle delay anyway?  What do you think?

Rick

 

----- Original Message ----- 

From: Bill Auerbach <mailto:[email protected]>  

To: 'Rick <mailto:[email protected]>  Culver' ; 'Mailing list for
lwIP users' <mailto:[email protected]>  

Sent: Thursday, April 23, 2009 5:07 PM

Subject: RE: [lwip-users] httpd slow response

 

Raw API doesn't disable Nagle.  I found things to be faster if I do so:

 

pcb->flags |= TF_NODELAY;                                        //
Disable Nagle

 

Bill

 

From: [email protected]
[mailto:[email protected]] On Behalf
Of Rick Culver
Sent: Thursday, April 23, 2009 4:05 PM
To: [email protected]
Subject: [lwip-users] httpd slow response

 

I am using lwip with raw API and the httpd web server.  I noticed that when
serving up larger files that the response seemed extremely slow.  The
http_sent() callback is used to send each new chunk of the file being served
and I discovered that it is taking about 175msec between the http_sent()
callbacks.  What could be causing this huge delay in response?  Any ideas
would could be wrong and/or how we can speed up this otherwise slow server?

 

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