Re: [dpdk-dev] [PATCH] app/testpmd: configure rxd and txd number correctly

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 4/17/2020 11:59 AM, Lijun Ou wrote:
> When users configure rxds and txds by used port config cmd based
> on testpmd application, it will not be able to configure rxd and
> txd according to the max capability range supported by the actual
> NIC hardware. Due testpmd defects, it can only configure a fixed
> range to 0 to 2048.
> The final result is that an incorrect printing prompt appears and
> cannot be applied using rxd && txd according to the actual
> capabilities supported by the device.
> In order to solve the above problems, we modify the testpmd. First
> by calling the rte_eth_dev_info_get api to obtain the max and min
> rx/tx capability supported by the hns3, and then use this range
> to compare with the actual value by users configured and make
> reasonable limitation.
> 
> Signed-off-by: Lijun Ou <oulijun@huawei.com>
> Signed-off-by: Huisong Li <lihuisong@huawei.com>
> Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>

<...>

> @@ -1212,6 +1383,8 @@ init_config(void)
>  	lcoreid_t  lc_id;
>  	uint8_t port_per_socket[RTE_MAX_NUMA_NODES];
>  	struct rte_gro_param gro_param;
> +	uint16_t allowed_max_rxd;
> +	uint16_t allowed_max_txd;
>  	uint32_t gso_types;
>  	uint16_t data_size;
>  	bool warning = 0;
> @@ -1239,6 +1412,9 @@ init_config(void)
>  		fwd_lcores[lc_id]->cpuid_idx = lc_id;
>  	}
>  
> +	allowed_max_rxd = RTE_TEST_RX_DESC_MAX;
> +	allowed_max_txd = RTE_TEST_RX_DESC_MAX;
> +
>  	RTE_ETH_FOREACH_DEV(pid) {
>  		port = &ports[pid];
>  		/* Apply default TxRx configuration for all ports */
> @@ -1299,6 +1475,13 @@ init_config(void)
>  				warning = 1;
>  			}
>  		}
> +
> +		/* Get the maximum number of txd and rxd per queue. */
> +		if (port->dev_info.tx_desc_lim.nb_max > allowed_max_rxd)
> +			allowed_max_txd = port->dev_info.tx_desc_lim.nb_max;
> +
> +		if (port->dev_info.rx_desc_lim.nb_max > allowed_max_txd)
> +			allowed_max_rxd = port->dev_info.rx_desc_lim.nb_max;
>  	}
>  
>  	if (warning)
> @@ -1317,9 +1500,9 @@ init_config(void)
>  	if (param_total_num_mbufs)
>  		nb_mbuf_per_pool = param_total_num_mbufs;
>  	else {
> -		nb_mbuf_per_pool = RTE_TEST_RX_DESC_MAX +
> +		nb_mbuf_per_pool = allowed_max_rxd +
>  			(nb_lcores * mb_mempool_cache) +
> -			RTE_TEST_TX_DESC_MAX + MAX_PKT_BURST;
> +			allowed_max_txd + MAX_PKT_BURST;

Overall patch looks good, but with above change, for the PMDs that doesn't
explicitly set 'dev_info.tx_desc_lim.nb_max' gets the default value
'UINT16_MAX', like virtual PMDs, and this increases the memmory requirement a lot.

What do you think to keep "port config all rxd|txd <value>" the fix, but remove
above nb_mbuf change?