Re: [PATCH net-next] r8152: divide the tx and rx bottom functions

From: Eric Dumazet
Date: Fri Aug 16 2019 - 02:40:08 EST




On 8/14/19 10:30 AM, Hayes Wang wrote:
> Move the tx bottom function from NAPI to a new tasklet. Then, for
> multi-cores, the bottom functions of tx and rx may be run at same
> time with different cores. This is used to improve performance.
>
>

tasklet and NAPI are scheduled on the same core (the current
cpu calling napi_schedule() or tasklet_schedule())

I would rather not add this dubious tasklet, and instead try to understand
what is wrong in this driver ;)

The various napi_schedule() calls are suspect IMO.

Also rtl8152_start_xmit() uses skb_queue_tail(&tp->tx_queue, skb);

But I see nothing really kicking the transmit if tx_free is empty ?

tx_bottom() is only called from bottom_half() (called from r8152_poll())