From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cong Wang <xiyou.wangcong@gmail.com>
Subject: Re: [PATCH net-next] net:sched: add gkprio scheduler
Date: Tue, 8 May 2018 19:24:35 -0700
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References: <20180507093626.GA5794@gmail.com> <CAM_iQpUpVdgQ+ED+Mbzpz6NZLQjzPR+vKcS5Zgv1F+_xysCQcg@mail.gmail.com>
 <20180508101210.GB4383@gmail.com> <273f91db-7a2f-acda-b306-5a78dd948478@digirati.com.br>
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Cc: Nishanth Devarajan <ndev2021@gmail.com>,
        Jiri Pirko <jiri@resnulli.us>,
        Jamal Hadi Salim <jhs@mojatatu.com>,
        David Miller <davem@davemloft.net>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>,
        Cody Doucette <doucette@bu.edu>
To: Michel Machado <michel@digirati.com.br>
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On Tue, May 8, 2018 at 5:59 AM, Michel Machado <michel@digirati.com.br> wrote:
>>> Overall it looks good to me, just one thing below:
>>>
>>>> +struct Qdisc_ops gkprio_qdisc_ops __read_mostly = {
>>>> +       .id             =       "gkprio",
>>>> +       .priv_size      =       sizeof(struct gkprio_sched_data),
>>>> +       .enqueue        =       gkprio_enqueue,
>>>> +       .dequeue        =       gkprio_dequeue,
>>>> +       .peek           =       qdisc_peek_dequeued,
>>>> +       .init           =       gkprio_init,
>>>> +       .reset          =       gkprio_reset,
>>>> +       .change         =       gkprio_change,
>>>> +       .dump           =       gkprio_dump,
>>>> +       .destroy        =       gkprio_destroy,
>>>> +       .owner          =       THIS_MODULE,
>>>> +};
>>>
>>>
>>> You probably want to add Qdisc_class_ops here so that you can
>>> dump the stats of each internal queue.
>
>
> Hi Cong,
>
>    In the production scenario we are targeting, this priority queue must be
> classless; being classful would only bloat the code for us. I don't see
> making this queue classful as a problem per se, but I suggest leaving it as
> a future improvement for when someone can come up with a useful scenario for
> it.


Take a look at sch_prio, it is fairly simple since your internal
queues are just an array... Per-queue stats are quite useful
in production, we definitely want to observe which queues are
full which are not.