Re: [PATCH V1 net-next 0/2] net: fec: fix TX bandwidth fluctuations

From: Frieder Schrempf
Date: Tue Jun 08 2021 - 10:18:41 EST


Hi Joakim, hi Andrew,

On 08.06.21 05:23, Joakim Zhang wrote:
>
> Hi Frieder,
>
>> -----Original Message-----
>> From: Andrew Lunn <andrew@xxxxxxx>
>> Sent: 2021年5月27日 22:06
>> To: Joakim Zhang <qiangqing.zhang@xxxxxxx>
>> Cc: davem@xxxxxxxxxxxxx; kuba@xxxxxxxxxx; frieder.schrempf@xxxxxxxxxx;
>> netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; dl-linux-imx
>> <linux-imx@xxxxxxx>
>> Subject: Re: [PATCH V1 net-next 0/2] net: fec: fix TX bandwidth fluctuations
>>
>> On Thu, May 27, 2021 at 12:10:47PM +0000, Joakim Zhang wrote:
>>>
>>> Hi Frieder,
>>>
>>> As we talked before, could you please help test the patches when you are
>> free? Thanks.
>>
>> Hi Frieder
>>
>> If you can, could you also test it with traffic with a mixture of VLAN priorities.
>> You might want to force the link to 10Full, so you can overload it. Then see
>> what traffic actually makes it through.
>
> Did your mailbox get bombed, let you miss this mail, hope you can see this reply.
>
> Could you please give some feedback if it is possible? Thanks :-)

Thanks for the patches! As far as the bandwidth drops are concerned, this solves the problem. According to my simple iperf tests the untagged TX traffic now always goes to queue 0 and therefore doesn't see any random bandwidth limitations anymore.

Regarding Andrew's request for testing this with some tagged traffic mix, my problem is that though I have used VLANs before and know how to set them up, I've never done anything with QoS, so I don't really now how to set the priorities (looks like I need to set up internal priorities and egress mapping somehow!?). If you have any pointers for this it would be appreciated. I probably could do some quick verification tests, but I don't have the time to really dive into the topic.

Best regards
Frieder