Some Questions about the network data transmission mechanism

For some questions about the network data transmission mechanism-Linux general technology-Linux programming and kernel information, see the following for details. When the kernel calls the driver's sending function dev_queue_xmit, the process is like this:

Dev_queue_xmit ()-> qdisc_run ()->__ qdisc_run (dev)-> qdisc_restart ()-> dev_hard_start_xmit ()-> driver sending function, I cannot understand the following issues:

(1) In this process, the net_tx_action () function for sending Soft Interrupt does not appear. When will net_tx_action () be called?

(2) I have read the materials and said that the driver's sending function will add skb to completion_queue after sending the data, and then let net_tx_action () release the data,
That is to say, the driver does not release data, but instead releases multiple data at a time in net_tx_action. Is that true?

(3) Some code in net_tx_action () is also used to send data. What data is this part?

This part is a bit dizzy, and there is also a bit confused about the Soft Interrupt call time of data reception. I beg you to give me some advice ~~

[ This post was last edited by ppb0320]