is polling still a thing?

[Jim Thompson]

> On Jan 27, 2015, at 2:28 PM, Olivier Cochard-Labbé <olivier at cochard.me> wrote:
> 
> On Tue, Jan 27, 2015 at 9:15 PM, Michael Sierchio <kudzu at tenebras.com <mailto:kudzu at tenebras.com>> wrote:
> 
> 
> On small, embedded computers running ipfw w/kernel nat and device polling enabled (on em ether adapters), I observed the *reported* system load grow very high. When disabling polling on the interfaces, it went back to something normal.
> 
> My impression is that the consensus among the core developers concerned with networking is that device polling is an ancient hack and is deprecated. In the case of a DDoS attack, there may be many other things to try - at the infrastructure level - traffic diversion techniques like BGP flowspec, use anycast, etc.  On the individual server level, use stateful rules with GRED enabled, dropping most new tcp or udp traffic based on load.
> 
> 
> 
> If I remember well, Luigi had a surprise regarding the advantage of using polling inside a VM:
> https://lists.freebsd.org/pipermail/freebsd-net/2013-May/035626.html <https://lists.freebsd.org/pipermail/freebsd-net/2013-May/035626.html>
> 
> But on real hardware, since the introduction of interrupt moderation on NIC, polling is not more useful.

The DPDK guys disagree.