[Codel] New to codel-- how to run codel on a linux box?

Dave Taht dave.taht at gmail.com
Sat Nov 23 09:43:44 EST 2013


Why burst 15k? Quantum 1514 works for me.

While htb will give the best results it is also the most CPU intensive.

I also note that running it on ingress can be useful especially with ecn.

IF you have a simple network driver with no ring buffer... Or you have
working BQL... And  you want to run at line rate at 100 Mbit... You can
tell your Ethernet driver to switch to 100mbit via

ethtool -s your device advertise 0x008

See also caveats on tso etc:

http://www.bufferbloat.net/projects/codel/wiki/Best_Practices_for_Benchmarking_CoDel_and_FQ_CoDel
 On Nov 23, 2013 2:26 AM, "Jonathan Morton" <chromatix99 at gmail.com> wrote:

>
> On 23 Nov, 2013, at 7:04 am, Dong Mo wrote:
>
> > I am new to codel and I would like to run some experiments with codel on
> a linux box acting as a router. I see on the wiki that running codel on
> linux requires BQL support from NIC driver. I would like to know is this an
> essential requirement to run codel on linux box or it is optional?
>
> It's not a hard requirement - but large hardware queues (which BQL tries
> to solve) tend to interfere with line-rate operation.
>
> > I don't require line rate performance, something like 100Mbps throughput
> will be enough for the experiment. However, It is also not clear to me that
> how Codel is going to interact with some software traffic shaping say
> bandwidth limiting?
>
> tc qdisc add dev $IFACE root handle 1: htb default 1
> tc class add dev $IFACE parent 1: classid 1:1 htb rate $RATE burst 15k
> tc qdisc add dev $IFACE parent 1:1 handle 10: fq_codel
>
> That works perfectly well if $RATE is less than line rate, even without
> BQL.
>
>  - Jonathan Morton
>
> _______________________________________________
> Codel mailing list
> Codel at lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/codel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.bufferbloat.net/pipermail/codel/attachments/20131123/66096809/attachment-0002.html>


More information about the Codel mailing list