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

Dong Mo montedong at gmail.com
Thu Dec 5 14:36:54 EST 2013

Thanks for the reply and I think I have successfully set up codel.
Unfortunately I am also new to qdisc.

I am trying to compare fq_codel and sfq's performance. I was wondering how
to setup a software rate limiting using htb and at the same time have sfq
on this bottleneck link using qdisc.

Thank you so much!

2013/11/23 Dave Taht <dave.taht at gmail.com>

> 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
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