[lwip-devel] On PBUF was: Work on tcp_enqueue

[Alain M.]

I am jijacking this thread for a subject that has come along in it:

PBUF

I would like to suggest a place to list all different necessities 
regarding pbufs, maybe a special page in the wiki (if many devellopers 
can have write access)

There are lots of different aspects, just to name a few:
- zero copy
- copy optimyzed: on 32 bit archs, an specially ARM and CortexM3 there a 
lot of tricks to speed up copy about 5 times!! things like word aligment 
but also multiples or 4/8 words for fast copy, etc..
- DMA: this is very usefull and varies wildly in various archs
- internal copy and pbuf list, as stated in this mesage about tcp_enqueue
- etc..

Maybe that if we manage to put all this toghether, a future version or 
patch could be more flexible!!

first list what is needed
second plan
third to it, if someone volunteers, of course :)

Alain


Jakob Stoklund Olesen escreveu:
> Follow-up Comment #8, task #7040 (project lwip):
>
> First of all: I am sorry for posting comments directly to the lwip-devel
> list. For any new listeners out there, there is some discussion about this
> task in the January 2009 archives of lwip-devel.
>
> I have attached a patch for tcp_enqueue that fixes the issue discussed here.
> It was not as simple as I had hoped. The tcp_enqueue function is quite scary.
> I have tested this patch, but please try to test it on different systems.
> There are many things that can go wrong.