Re: [PATCH net-next 10/10] net: hns3: Add mqprio support when interacting with network stack

[Jiri Pirko <jiri@resnulli.us>]

Fri, Sep 22, 2017 at 04:11:51PM CEST, linyunsheng@huawei.com wrote:
>Hi, Jiri
>
>>>- if (!tc) {
>>>+ if (if_running) {
>>>+ (void)hns3_nic_net_stop(netdev);
>>>+ msleep(100);
>>>+ }
>>>+
>>>+ ret = (kinfo->dcb_ops && kinfo->dcb_ops->>setup_tc) ?
>>>+ kinfo->dcb_ops->setup_tc(h, tc, prio_tc) : ->EOPNOTSUPP;
>
>>This is most odd. Why do you call dcb_ops from >ndo_setup_tc callback?
>>Why are you mixing this together? prio->tc mapping >can be done
>>directly in dcbnl
>
>Here is what we do in dcb_ops->setup_tc:
>Firstly, if current tc num is different from the tc num
>that user provide, then we setup the queues for each
>tc.
>
>Secondly, we tell hardware the pri to tc mapping that
>the stack is using. In rx direction, our hardware need
>that mapping to put different packet into different tc'
>queues according to the priority of the packet, then
>rss decides which specific queue in the tc should the
>packet goto.
>
>By mixing, I suppose you meant why we need the
>pri to tc infomation?

by mixing, I mean what I wrote. You are calling dcb_ops callback from
ndo_setup_tc callback. So you are mixing DCBNL subsystem and TC
subsystem. Why? Why do you need sch_mqprio? Why DCBNL is not enough for
all?



>I hope I did not misunderstand your question, thanks
>for your time reviewing.