On 07/01/2014 06:33 AM, David Miller wrote:

From: Amir Vadai <redacted>
Date: Mon, 30 Jun 2014 11:34:22 +0300

quoted

On 6/30/2014 9:41 AM, Eric Dumazet wrote:

quoted

You might want to drain whole queue instead of limiting to a 'budget',
otherwise, a cpu might be stuck servicing (soft)irq for the TX
completion, even if irq affinities say otherwise.

TX completions are very quick compared to the skb preparation and
sending. Which is not the case for RX completions. Because of that, it
is very easy to reproduce the problem in RX flows, but we never had any
report of that problem in the TX flow.
I prefer not to spend time on the TX, since we plan to send a patch soon
to use the same NAPI for both TX and RX.

It is always advised to completely ignore the budget for TX work, this is
what we tell every driver author when discussion NAPI implementations.

Please make your driver conform to this, thanks.

Ok.

Please continue the process on this V1 of the patchset. The fix to TX 
poll is not related to this patch - this patch is fixing a regression 
that broke aRFS in mlx4_en.

I will send a separate fix to purge all packets on TX work later on this 
week.

Thanks,
Amir