Re: 答复: [PATCH v8 12/17] net/r8169: implement Tx path

[Thomas Monjalon <thomas@monjalon.net>]

The change below is replacing 1 rte_smp_rmb with 2 calls,
so no it is not what I am asking for.
Please could you check how to not calling this function at all?

This series is already merged in the main branch,
so any new change should be submitted as a new patch.

Thank you


19/11/2024 07:29, 王颢:
> Dear Thomas,
> 
> After our discussion, we concluded that we can make the following changes. What do you think? Additionally, I may not have been very clear in my last email. Should I submit the entire series of changes as PATCH v9, or should I respond with [PATCH v9 12/17] net/r8169: implement Tx path?
> 
> static u32
> rtl_get_opts1(struct rtl_tx_desc *txd)
> {
> -	rte_smp_rmb();
> 
> 	return rte_le_to_cpu_32(txd->opts1);
> }
> 
> static void
> rtl_tx_clean(struct rtl_hw *hw, struct rtl_tx_queue *txq)
> {
> 		...
> 		tx_left = (rte_atomic_load_explicit(&txq->tx_tail,
> 						    rte_memory_order_relaxed) % nb_tx_desc) - head;
> 	}
> 
> +	rte_smp_rmb();
> 
> 	while (tx_left > 0) {
> 		txd = &txq->hw_ring[head];
> 
> 		if (!enable_tx_no_close && (rtl_get_opts1(txd) & DescOwn))
> 			break;
> 		...
> }
> 
> 
> int
> rtl_tx_done_cleanup(void *tx_queue, uint32_t free_cnt)
> {
> 		...
> 		tx_left = (rte_atomic_load_explicit(&txq->tx_tail,
> 						    rte_memory_order_relaxed) % nb_tx_desc) - head;
> 	}
> 
> +	rte_smp_rmb();
> 
> 	while (tx_left > 0) {
> 		txd = &txq->hw_ring[head];
> 
> 		status = rtl_get_opts1(txd);
> 
> 		if (!enable_tx_no_close && (status & DescOwn))
> 			break;
> 
> 		...
> }
> 
> Best Regards,
> Howard Wang
> 
> -----邮件原件-----
> 发件人: Thomas Monjalon <thomas@monjalon.net> 
> 发送时间: 2024年11月18日 22:59
> 收件人: pro_nic_dpdk@realtek.com; 王颢 <howard_wang@realsil.com.cn>
> 抄送: dev@dpdk.org; Ferruh Yigit <ferruh.yigit@amd.com>
> 主题: Re: [PATCH v8 12/17] net/r8169: implement Tx path
> 
> 
> External mail.
> 
> 
> 
> Hello,
> 
> 13/11/2024 10:28, Howard Wang:
> > +static u32
> > +rtl_get_opts1(struct rtl_tx_desc *txd) {
> > +       rte_smp_rmb();
> > +
> > +       return rte_le_to_cpu_32(txd->opts1); }
> 
> We should avoid using such heavy memory barrier.
> Is it possible to use a lighter fence or atomic API?
> 
> 
>