[OpenWrt-Devel] Introducing "fastpath" - Kernel module for speeding up IP forwarding

[valent.turkovic at gmail.com]

A long shot, but are there any news from Marvel legal department? Would
sending them a case of good beer solve this? :)

On Sunday, 27 September 2015, Weedy <weedy2887 at gmail.com> wrote:

> Did this die?
> On 22 Dec 2014 9:06 am, "Tomer Eliyahu" <tomereliyahu1 at gmail.com
> <javascript:_e(%7B%7D,'cvml','tomereliyahu1 at gmail.com');>> wrote:
>
>> Hi,
>>
>> We are software developers, part of Marvell's cellular platform
>> infrastructure team.
>>
>> Our team has been working on a project named "fastpath" for speeding
>> up IP forwarding in embedded systems.
>> The initial version (fastpath v1) has already been successfully
>> deployed in our latest pxa1801 (cellular modem) based products.
>>
>> We are in the final stages of fastpath v2 development, which is
>> completely hardware independent and requires minimal changes in the
>> generic networking code (the project consists of a kernel module and a
>> single kernel patch); despite being hardware independent, fastpath v2
>> already achieved the same level of performance (as fastpath v1) and
>> even increased stability.
>>
>> Our development platform is running openwrt Barrier Breaker (r43694),
>> so naturally we chose to suggest this to the openwrt development
>> community first.
>>
>> You can find a brief description of our fastpath solution below.
>>
>> We are anxious to hear your thoughts/comments and will gladly share the
>> code.
>>
>> Best Regards,
>>
>> Ram Marzin ramm at marvell.com
>> <javascript:_e(%7B%7D,'cvml','ramm at marvell.com');>
>> Tomer Eliyahu tomere at marvell.com
>> <javascript:_e(%7B%7D,'cvml','tomere at marvell.com');>
>>
>>
>> Fastpath in a nutshell
>> ----------------------
>>
>> The basic concept of fastpath is to optimize the data-plane while
>> keeping the control-plane in the generic networking stack.
>> This is a known concept in the industry which is commonly used in
>> embedded systems [1], but so far we couldn't find any open source
>> implementation for it.
>>
>> Fast path implements an optimized data-plane, which replaces the
>> generic data-plane forwarding code for selected connections. The
>> data-plane implementation includes a straight forward optimized packet
>> processing engine which handles all the required packet manipulation
>> for IP forwarding, such as decrement ttl/hop count, checksum
>> adjustment, MAC header encapsulation and "dummy NAT" (TCP/UDP traffic
>> which does not carry any L3/L4 information in the packet payload).
>>
>> As noted above, the control-plane is handled by the generic networking
>> stack, with the only exception of learning new connections and marking
>> the valid ones as fastpath - some connections can't participate in
>> fastpath, such as any "non-dummy NAT" connections (e.g. FTP control
>> port), local traffic, and any protocol which is not supported (e.g.
>> IPv6 extensions, IPSec, IPv4 fragmanted packets, etc.).
>> Needless to say that ALL non-fastpath connections / protocols will
>> work as is, i.e. they simply won't go through fastpath.
>>
>> As a rule of thumb, it is safe to assume that in most of the cases,
>> 90% of the data will go through fastpath. In our experiments on
>> pxa1801, fastpath alone *almost doubled* the performance (both
>> Throughput and MIPS consumption) for TCP/UDP IPv4/IPv6 forwarding.
>>
>> References
>> [1]
>> http://www.embedded.com/design/operating-systems/4403058/Accelerating-network-packet-processing-in-Linux
>> _______________________________________________
>> openwrt-devel mailing list
>> openwrt-devel at lists.openwrt.org
>> <javascript:_e(%7B%7D,'cvml','openwrt-devel at lists.openwrt.org');>
>> https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
>>
>
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