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

On Tue, Jan 31, 2017 at 11:12:25PM -0500, David Miller wrote:

From: Corentin Labbe <clabbe.montjoie@gmail.com>
Date: Tue, 31 Jan 2017 10:11:48 +0100

quoted

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)

So perhaps the best way is to do like intel igb/ixgbe, keeping under NAPI until the stmmac_tx_clean function said that it finish handling the queue ?

Regards
Corentin Labbe