[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [lwip-users] Interniche and lwIP
From: |
Timmy Brolin |
Subject: |
Re: [lwip-users] Interniche and lwIP |
Date: |
Thu, 09 Jul 2009 19:36:27 +0200 |
User-agent: |
Thunderbird 2.0.0.22 (Windows/20090605) |
> But the problems/disadvantages with Interniche:
>
> 6 They support scatter-gather DMA in hardware but their driver doesn't take
> advantage of it.
>
Unless things have changed recently in Interniche land, this is also the
main reason why Interniche uses much more RAM than lwIP.
A full 1518 Byte buffer has to be allocated for every incoming packet,
unless you want to do one extra copy and reallocation operation in the
Ethernet driver.
Just this week I found bugs in Interniche IP fragmentation routines as
well as in the handling of IP options.
> The good parts:
> 2. The scatter-gather DMA is nice if utilized.
>
Most processors with integrated 100Mbit MAC supports scatter-gather.
Not really a noteworthy feature unless it supports some more advanced
features such as automatic TCP/IP header length detection so that the
scatter transfer can separate the TCP/IP or UDP/IP header from the
payload, even when the headers may have varying lengths due to header
options and vlan tags.
If combined with a finely grained MMU, such a feature would allow true
zero copy without the hazzle of having to handle pbuf chains in the
application layer.
/Timmy Brolin
- Re: [lwip-users] how to send udp messages circularly ?, (continued)
- Re: [lwip-users] how to send udp messages circularly ?, the_gadfly, 2009/07/08
- Re: [lwip-users] how to send udp messages circularly ?, Kieran Mansley, 2009/07/08
- Re: [lwip-users] how to send udp messages circularly ?, Simon Goldschmidt, 2009/07/08
- Re: [lwip-users] how to send udp messages circularly ?, Kieran Mansley, 2009/07/08
- Re: [lwip-users] how to send udp messages circularly ?, the_gadfly, 2009/07/08
- Re: [lwip-users] how to send udp messages circularly ?, address@hidden, 2009/07/08
- Re: [lwip-users] how to send udp messages circularly ?, address@hidden, 2009/07/08
- RE: [lwip-users] how to send udp messages circularly ?, Bill Auerbach, 2009/07/08
- Re: [lwip-users] how to send udp messages circularly ?, address@hidden, 2009/07/08
- RE: [lwip-users] Interniche and lwIP (was: how to send udp messages circularly ?), Bill Auerbach, 2009/07/09
- Re: [lwip-users] Interniche and lwIP,
Timmy Brolin <=
- Re: [lwip-users] Interniche and lwIP, address@hidden, 2009/07/10