Re: [lwip-users] With logs ... Re: Delayed Ack causing problems? Where to call tcp_nagle_disable()?

[address@hidden]

FreeRTOS Info wrote:
> That would be excellent - and exactly the feedback I would look for.

Alright, so it turns out the lwipopts.h *was* the reason for the poor 
performance. Using the LPC17xx one, I had the same poor performance with 
my win32 port. I got it working by changing the following line:

#define TCP_SND_BUF                (TCP_MSS*2) // was: 2048

That ensures that TCP isn't limited too before sending 2 mss-sized 
segments (which is the borderline for delayed ACKs on most systems).

BTW: there *are* sanity checks for these defines in init.c. However, 
they are (yet) runtime checks that output a warning via 
LWIP_PLATFORMDIAG in LWIP_DEBUG mode, so there's a high risk of not 
seeing them. Given the time we spent on this, I'll change them to 
compile-time errors that can be disabled. There are also other sanity 
checks that fail with your configuration. While these can be ignored in 
the very special case of the webserver, I'd strongly recommend to change 
your lwipopts.h to obey all of them.

I'll update init.c in git these days, and I'll have to adapt the default 
values in opt.h, too, since they fail the sanity checks, too :-(  --> 
bad example!

Simon