From: Eric Dumazet <[email protected]> Date: Fri, 08 May 2015 15:05:12 -0700
> From: Eric Dumazet <[email protected]> > > For DCTCP or similar ECN based deployments on fabrics with shallow > buffers, hosts are responsible for a good part of the buffering. > > This patch adds an optional ce_threshold to codel & fq_codel qdiscs, > so that DCTCP can have feedback from queuing in the host. > > A DCTCP enabled egress port simply have a queue occupancy threshold > above which ECT packets get CE mark. > > In codel language this translates to a sojourn time, so that one doesn't > have to worry about bytes or bandwidth but delays. > > This makes the host an active participant in the health of the whole > network. > > This also helps experimenting DCTCP in a setup without DCTCP compliant > fabric. > > On following example, ce_threshold is set to 1ms, and we can see from > 'ldelay xxx us' that TCP is not trying to go around the 5ms codel > target. > > Queue has more capacity to absorb inelastic bursts (say from UDP > traffic), as queues are maintained to an optimal level. ... > Signed-off-by: Eric Dumazet <[email protected]> Applied, thanks a lot Eric. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
