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

From: David Miller
Date: Tue Jan 31 2017 - 23:12:49 EST


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.