zero_copy in RTEMS

[leonp at plris.com (Leon Pollak)]

On Wednesday February 10 2010, Lu Chih Wen wrote:
> Hello all
> 
> 
> 
> I have an idea about the implementation of zero-copy on RTEMS's TCP/IP
> stack.
> 
> The major concept about zero-copy is decrease the copy time of mbuf->m_data
> to application's buffer,
> 
> So I try to allocate mbuf chain in application and swap the appended
>  cluster buffer between protocol
> 
> and application in socket layer. I have implemented in my test platform and
> got a lot of increase of performance/
> 
> Was anyone did this before? I hope someone can point out more detail that I
> should aware of .
> 
> 
> 
> RX sequence!
> 
> MAC HW fill driver's allocated mbuf->m_data(Cluster buffer ) -> TCP/IP ->
> swap cluster buffer in socket layer --> return to Application.
> 
> TX sequence!
> 
> Application fill the data in mbuf->m_data(Cluster buffer ) -> Swap cluster
> buffer in socket layer -> TCP/IP ---> MAC driver.
> 
> 
> 
> Yours sincerely
> 
> Rudolph.Lu
> 
Sounds GREAT!!!!
BR
-- 
Leon