[sr-dev] git:andrei/raw_sock: core: basic raw socket support functions

[Henning Westerholt]

On Friday 11 June 2010, Andrei Pelinescu-Onciul wrote:
> [..]
> > So it might be a good idea to evaluate how big is the actual improvement
> > with raw sockets over the multiple sockets, if its make sense to from a
> > maintenance POV to go with this solution (not sure how complicated the
> > actual implementation will be..).
> 
> We cannot go with multiple udp sockets because then we will have
> multiple source ports, which is something one does not want for a sip
> proxy (think natted UACs).
> A possible workaround is to use multiple ports and SRV records to
> balance the traffic on them, but IMHO the raw socket should solve the
> problem in a simpler way (from the sr.cfg point of view). The only
> problem is finding the right MTU, but I guess for most setups (that
> don't use multiple interfaces with different MTUs) a sr.cfg configurable
> mtu would do (at least for the initial version).
> 
> Anyway from the coding point of view I'm almost ready, the testing will
> be more difficult.

Hi Andrei,

thanks for the clarification. I completely forgot about the problem with the 
multiple source ports.. Just as a side note, maybe also interesting in this 
problem space are the new RFS/RPS implementations in upcoming 2.6.35:

http://lwn.net/Articles/382428/
http://lwn.net/Articles/362339/

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=0a9627f2649a02bea165cfd529d7bcb625c2fcad
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=fec5e652e58fa6017b2c9e06466cb2a6538de5b4

even if in the patches they mentioned mainly TCP based workloads, the gains 
looks promising.
 
Regards,

Henning