This qdisc aims to eliminate bufferbloat and as a side effect improves
latency during heavy network load. The most notable effect will be a
slightly more responsive ssh session during large downloads.
Systemd will autoselect fq_codel when it's available:
m8s:~ # ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 4096 qdisc noqueue
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP8000> mtu 1500 qdisc fq_codel qlen 1000
link/ether 82:cd:fa:1b:03:1d brd ff:ff:ff:ff:ff:ff
inet 172.20.0.166/24 brd 172.20.0.255 scope global eth0
valid_lft forever preferred_lft forever
3: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP,LOWER_UP8000> mtu 1500 qdisc fq_codel qlen 1000
link/ether 44:2c:05:43:8c:eb brd ff:ff:ff:ff:ff:ff
inet6 fe80::462c:5ff:fe43:8ceb/64 scope link
valid_lft forever preferred_lft forever
On the S905X 100Mbit link it shows no negative effects:
m8s:~ # curl http://beast.local/koen/largefile.mkv --http1.1 > /dev/null
% Total % Received % Xferd Average Speed Time Time
% Time
% Current
Dload Upload Total Spent Left Speed
7 14.9G 7 1105M 0 0 11.1M 0 0:22:50 0:01:38 0:21:12 11.2M
See https://en.wikipedia.org/wiki/CoDel for more information on CODEL
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
