On Sat, Jul 7, 2018 at 3:14 AM Nishanth Devarajan <[email protected]> wrote:
> diff --git a/Documentation/networking/sch_skbprio.txt
> b/Documentation/networking/sch_skbprio.txt
> new file mode 100644
> index 0000000..3aa4d3e
> --- /dev/null
> +++ b/Documentation/networking/sch_skbprio.txt
We usually document each qdisc behavior in tc man pages in iproute2.
I don't mind you document it in kernel, but it kinda breaks the tradition.
> +static int skbprio_change(struct Qdisc *sch, struct nlattr *opt,
> + struct netlink_ext_ack *extack)
> +{
> + struct skbprio_sched_data *q = qdisc_priv(sch);
> + struct tc_skbprio_qopt *ctl = nla_data(opt);
> + const unsigned int min_limit = 1;
> +
> + if (ctl->limit == (typeof(ctl->limit))-1)
> + sch->limit = max(qdisc_dev(sch)->tx_queue_len, min_limit);
> + else if (ctl->limit < min_limit)
> + return -EINVAL;
> + else
> + sch->limit = ctl->limit;
The dev->tx_queue_len is fundamentally non-sense since now
almost every real NIC is multi-queue and qdisc has a completely
different sch->limit. This is why I suggested you to simply
avoid it in your code.
There is no standard way to use dev->tx_queue_len in kernel,
so I can't claim your use is correct or not, but it still looks odd,
other qdisc seems just uses as a default, rather than picking
the smaller or bigger value as a cap.
