> On Apr 6, 2017, at 12:50 PM, Toke Høiland-Jørgensen <[email protected]> wrote:
>
> Pete Heist <[email protected] <mailto:[email protected]>> writes:
>
>> The fq_codel qdisc does have support for arbitrary tc filters to replace
>> the default hashing, BTW. If you don't need the cake shaper, that might
>> be a solution?
>>
>> I see, I found mention of it in Chapter 6 of a draft RFC that it looks
>> like you wrote, actually
>> (https://tools.ietf.org/html/draft-ietf-aqm-fq-codel-06#section-6). :)
>> To try it out, am I heading the right direction by looking at tc
>> filter’s skbedit action, or is that just for MQ devices?
>> (http://man7.org/linux/man-pages/man8/tc-skbedit.8.html)
>>
>> I also saw this mention of “We are not aware of any deployments
>> utilising the custom classification feature"
>> https://tools.ietf.org/html/draft-ietf-aqm-fq-codel-02#section-5.1.1,
>> so not sure how often this has been tried. :)
>
> Yeah, haven't actually heard of anyone using the feature in production.
> It's basically this section from the 'classful qdiscs' section of 'man
> tc':
>
> When a packet enters a classful qdisc it can be classified to one of
> the classes within. Three criteria are available, although not all qdiscs
> will use all three:
>
> tc filters
> If tc filters are attached to a class, they are consulted first
> for relevant instructions. Filters can match on all fields of a packet
> header, as well as on the firewall mark applied by ipchains or iptables.
>
> So you can basically use the full capabilities of tc-filter in place of
> the built-in hashing of fq_codel. The tc-u32 man page has some examples,
> which is probably a good starting point.
>
> If you do try this out and feel like writing up a small
> example/tutorial, I'm happy to add a link (or the whole thing) somewhere
> on bufferbloat.net <http://bufferbloat.net/> :)
Sure, if I get it working I’ll include an example in my paper, but I’m still a
little confused. Is fq_codel actually a classful qdisc?
I get the part about matching with tc-filter and the u32 selector (as intuitive
as that is :), but am not sure of the action the filter needs to take. However,
I do see the example towards the bottom of the tc-u32 man page where a hash
table is created and filters move packets into the right buckets. Perhaps it
will be eventually decipherable from this… :)
_______________________________________________
Cake mailing list
[email protected]
https://lists.bufferbloat.net/listinfo/cake
