[Cake] tunable delays for tcp

[Dave Taht]

this commit from the immortal edumazet arrived this morning in net-next:

https://www.spinics.net/lists/netdev/msg577452.html

...

> Adding delays to TCP flows is crucial for studying behavior
> of TCP stacks, including congestion control modules.
>
> Linux offers netem module, but it has unpractical constraints :
> - Need root access to change qdisc
> - Hard to setup on egress if combined with non trivial qdisc like FQ
> - Single delay for all flows.
>
> EDT (Earliest Departure Time) adoption in TCP stack allows us
> to enable a per socket delay at a very small cost.
>
> Networking tools can now establish thousands of flows, each of them
> with a different delay, simulating real world conditions.
>
> This requires FQ packet scheduler or a EDT-enabled NIC.


-- 

Dave Täht
CTO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-831-205-9740