Re: [lwip-users] Zero Copy Ethernet interface

[Jonathan Larmour]

Andrew Dennison wrote:
> > [re andrew's mail:]
> >
> > > input_thread_loop:
> > >     pbuf_alloc() 1514 bytes
> > >     pass pbuf to driver and block waiting for packet then DMA from
> > device
> > >     pbuf_realloc() <- trim to actual length
> > >     netif->input()
[snip]
> I'm interested to hear if you have ideas on how to improve my implementation.

I don't know if this is what Simon is alluding to, but if you get two 
receives in quick succession (which is surely quite likely), the way you 
describe your implementation would result in the second having a good 
chance of getting dropped because another pbuf wasn't ready yet. Point 
being, there's a window where no packet buffer is available.

Jifl
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