Re: [PATCH 13/17] net: stmmac: Implement NAPI for TX

From: David Miller
Date: Fri Feb 03 2017 - 10:15:39 EST


From: Corentin Labbe <clabbe.montjoie@xxxxxxxxx>
Date: Fri, 3 Feb 2017 14:41:45 +0100

> On Tue, Jan 31, 2017 at 11:12:25PM -0500, David Miller wrote:
>> From: Corentin Labbe <clabbe.montjoie@xxxxxxxxx>
>> Date: Tue, 31 Jan 2017 10:11:48 +0100
>>
>> > The stmmac driver run TX completion under NAPI but without checking
>> > the work done by the TX completion function.
>>
>> The current behavior is correct and completely intentional.
>>
>> A driver should _never_ account TX work to the NAPI poll budget.
>>
>> This is because TX liberation is orders of magnitude cheaper than
>> receiving a packet, and such SKB freeing makes more SKBs available
>> for RX processing.
>>
>> Therefore, TX work should never count against the NAPI budget.
>>
>> Please do not fix something which is not broken.
>
> So at least the documentation I read must be fixed (https://wiki.linuxfoundation.org/networking/napi)

We have no control over nor care about what the Linux Foundation writes
about the Linux networking code.

Complain to them and please do not bother us about it.

Thank you.