[PATCH v7 18/21] net/cpfl: add HW statistics

[Ferruh Yigit]

On 2/28/2023 6:46 AM, Liu, Mingxia wrote:
> 
> 
>> -----Original Message-----
>> From: Ferruh Yigit <ferruh.yigit at amd.com>
>> Sent: Tuesday, February 28, 2023 5:52 AM
>> To: Liu, Mingxia <mingxia.liu at intel.com>; dev at dpdk.org; Xing, Beilei
>> <beilei.xing at intel.com>; Zhang, Yuying <yuying.zhang at intel.com>
>> Subject: Re: [PATCH v7 18/21] net/cpfl: add HW statistics
>>
>> On 2/16/2023 12:30 AM, Mingxia Liu wrote:
>>> This patch add hardware packets/bytes statistics.
>>>
>>> Signed-off-by: Mingxia Liu <mingxia.liu at intel.com>
>>
>> <...>
>>
>>> +static int
>>> +cpfl_dev_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats
>>> +*stats) {
>>> +	struct idpf_vport *vport =
>>> +		(struct idpf_vport *)dev->data->dev_private;
>>> +	struct virtchnl2_vport_stats *pstats = NULL;
>>> +	int ret;
>>> +
>>> +	ret = idpf_vc_stats_query(vport, &pstats);
>>> +	if (ret == 0) {
>>> +		uint8_t crc_stats_len = (dev->data-
>>> dev_conf.rxmode.offloads &
>>> +					 RTE_ETH_RX_OFFLOAD_KEEP_CRC) ?
>> 0 :
>>> +					 RTE_ETHER_CRC_LEN;
>>> +
>>> +		idpf_vport_stats_update(&vport->eth_stats_offset, pstats);
>>> +		stats->ipackets = pstats->rx_unicast + pstats->rx_multicast +
>>> +				pstats->rx_broadcast - pstats->rx_discards;
>>> +		stats->opackets = pstats->tx_broadcast + pstats->tx_multicast
>> +
>>> +						pstats->tx_unicast;
>>> +		stats->imissed = pstats->rx_discards;
>>> +		stats->oerrors = pstats->tx_errors + pstats->tx_discards;
>>> +		stats->ibytes = pstats->rx_bytes;
>>> +		stats->ibytes -= stats->ipackets * crc_stats_len;
>>> +		stats->obytes = pstats->tx_bytes;
>>> +
>>> +		dev->data->rx_mbuf_alloc_failed =
>>> +cpfl_get_mbuf_alloc_failed_stats(dev);
>>
>> 'dev->data->rx_mbuf_alloc_failed' is also used by telemetry, updating here
>> only in stats_get() will make it wrong for telemetry.
>>
>> Is it possible to update 'dev->data->rx_mbuf_alloc_failed' whenever alloc
>> failed? (alongside 'rxq->rx_stats.mbuf_alloc_failed').
> [Liu, Mingxia] As I know, rte_eth_dev_data is not a public structure provided to user, user need to access through rte_ethdev APIs.
> Because we already put rx and tx burst func to common/idpf which has no dependcy with ethdev lib. If I update "dev->data->rx_mbuf_alloc_failed" 
> when allocate mbuf fails, it will break the design of our common/idpf interface to net/cpfl or net.idpf.
> 
> And I didn't find any reference of 'dev->data->rx_mbuf_alloc_failed' in lib code.
> 

Please check 'eth_dev_handle_port_info()' function.
As I said this is used by telemetry, not directly exposed to the user.

I got the design concern, perhaps you can put a brief limitation to the
driver documentation.