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

[王颢 <howard_wang@realsil.com.cn>]

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?