On Fri, May 4, 2018 at 12:10 PM, Toke Høiland-Jørgensen <t...@toke.dk> wrote:
> Thank you for the review! A few comments below, I'll fix the rest.
>
>> [...]
>>
>> So sch_cake doesn't accept normal tc filters? Is this intentional?
>> If so, why?
>
> For two reasons:
>
> - The two-level scheduling used in CAKE (tins / diffserv classes, and
> flow hashing) does not map in an obvious way to the classification
> index of tc filters.
Sounds like you need to extend struct tcf_result?
>
> - No one has asked for it. We have done our best to accommodate the
> features people want in a home router qdisc directly in CAKE, and the
> ability to integrate tc filters has never been requested.
It is not hard to integrate, basically you need to call tcf_classify().
Although it is not mandatory, it is odd to merge a qdisc doesn't work
with existing tc filters (and actions too).
>>> +static int cake_init(struct Qdisc *sch, struct nlattr *opt,
>>> + struct netlink_ext_ack *extack)
>>> +{
>>> + struct cake_sched_data *q = qdisc_priv(sch);
>>> + int i, j;
>>> +
>>> + sch->limit = 10240;
>>> + q->tin_mode = CAKE_DIFFSERV_BESTEFFORT;
>>> + q->flow_mode = CAKE_FLOW_TRIPLE;
>>> +
>>> + q->rate_bps = 0; /* unlimited by default */
>>> +
>>> + q->interval = 100000; /* 100ms default */
>>> + q->target = 5000; /* 5ms: codel RFC argues
>>> + * for 5 to 10% of interval
>>> + */
>>> +
>>> + q->cur_tin = 0;
>>> + q->cur_flow = 0;
>>> +
>>> + if (opt) {
>>> + int err = cake_change(sch, opt, extack);
>>> +
>>> + if (err)
>>> + return err;
>>
>>
>> Not sure if you really want to reallocate q->tines below for this
>> case.
>
> I'm not sure what you mean here? If there's an error we return it and
> the qdisc is not created. If there's not, we allocate and on subsequent
> changes cake_change() will be called directly, or? Can the init function
> ever be called again during the lifetime of the qdisc?
>
In non-error case, you call cake_change() first and then allocate ->tins
with kvzalloc() below. For me it looks like you don't need to allocate it
again when ->tins!=NULL.
