On 2/28/2023 2:24 PM, Bruce Richardson wrote:
> On Tue, Feb 28, 2023 at 01:34:43PM +0000, Ferruh Yigit wrote:
>> On 2/28/2023 1:29 PM, Zhang, Qi Z wrote:
>>>
>>>
>>>> -----Original Message-----
>>>> From: Ferruh Yigit <ferruh.yi...@amd.com>
>>>> Sent: Tuesday, February 28, 2023 8:33 PM
>>>> To: Richardson, Bruce <bruce.richard...@intel.com>
>>>> Cc: Liu, Mingxia <mingxia....@intel.com>; dev@dpdk.org; Xing, Beilei
>>>> <beilei.x...@intel.com>; Zhang, Yuying <yuying.zh...@intel.com>; Wu,
>>>> Jingjing <jingjing...@intel.com>
>>>> Subject: Re: [PATCH v7 18/21] net/cpfl: add HW statistics
>>>>
>>>> On 2/28/2023 12:24 PM, Ferruh Yigit wrote:
>>>>> On 2/28/2023 12:12 PM, Bruce Richardson wrote:
>>>>>> On Tue, Feb 28, 2023 at 12:04:53PM +0000, Ferruh Yigit wrote:
>>>>>>> On 2/28/2023 11:47 AM, Liu, Mingxia wrote:
>>>>>>>
>>>>>>> Comment moved down, please don't top post, it makes very hard to
>>>>>>> follow discussion.
>>>>>>>
>>>>>>>>> -----Original Message----- From: Ferruh Yigit
>>>>>>>>> <ferruh.yi...@amd.com>
>>>>>>>>> Sent: Tuesday, February 28, 2023 6:02 PM To: Liu, Mingxia
>>>>>>>>> <mingxia....@intel.com>; dev@dpdk.org; Xing, Beilei
>>>>>>>>> <beilei.x...@intel.com>; Zhang, Yuying <yuying.zh...@intel.com>
>>>>>>>>> Subject: Re: [PATCH v7 18/21] net/cpfl: add HW statistics
>>>>>>>>>
>>>>>>>>> On 2/28/2023 6:46 AM, Liu, Mingxia wrote:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> -----Original Message----- From: Ferruh Yigit
>>>>>>>>>>> <ferruh.yi...@amd.com>
>>>>>>>>>>> Sent: Tuesday, February 28, 2023 5:52 AM To: Liu, Mingxia
>>>>>>>>>>> <mingxia....@intel.com>; dev@dpdk.org; Xing, Beilei
>>>>>>>>>>> <beilei.x...@intel.com>; Zhang, Yuying <yuying.zh...@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....@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.
>>>>>>>>>
>>>>>>>> OK, got it.
>>>>>>>>
>>>>>>>> As our previous design did have flaws. And if we don't want to
>>>>>>>> affect correctness of telemetry, we have to redesign the idpf
>>>>>>>> common module code, which means a lot of work to do, so can we
>>>>>>>> lower the priority of this issue?
>>>>>>>>
>>>>>>> I don't believe this is urgent, can you but a one line limitation to
>>>>>>> the documentation for now, and fix it later?
>>>>>>>
>>>>>>> And for the fix, updating 'dev->data->rx_mbuf_alloc_failed' where
>>>>>>> ever 'rxq->rx_stats.mbuf_alloc_failed' updated is easy, although you
>>>>>>> may need to store 'dev->data' in rxq struct for this.
>>>>>>>
>>>>>>> But, I think it is also fair to question the assumption telemetry
>>>>>>> has that 'rx_mbuf_alloc_fail' is always available data, and consider
>>>>>>> moving it to the 'eth_dev_handle_port_stats()' handler. +Bruce for
>>>> comment.
>>>>>>>
>>>>>>
>>>>>> That's not really a telemetry assumption, it's one from the stats,
>>>>>> structure. Telemetry just outputs the contents of data reported by
>>>>>> ethdev stats, and rx_nombuf is just one of those fields.
>>>>>>
>>>>>
>>>>> Not talking about 'rx_nombuf' in 'eth_dev_handle_port_stats()', but
>>>>> talking about 'rx_mbuf_alloc_fail' in 'eth_dev_handle_port_info()',
>>>>>
>>>>> should telemetry return interim 'eth_dev->data->rx_mbuf_alloc_failed'
>>>>> value, specially when 'rx_nombuf' is available?
>>>>>
>>>>> Because at least for this driver returned 'rx_mbuf_alloc_fail' value
>>>>> will be wrong, I believe that is same for 'idpf' driver.
>>>>>
>>>>>
>
> Thanks for the clarification, the question is clearer now. Having duplicate
> info seems strange.
>
>>>>
>>>> Or, let me rephrase like this,
>>>> 'eth_dev->data->rx_mbuf_alloc_failed' is not returned to user directly via
>>>> ethdev APIs, but it is via telemetry.
>>>>
>>>> I think it is not guaranteed that this value will be correct at any given
>>>> time as
>>>> telemetry assumes, so should we remove it from telemetry?
>>>
>>> May not be necessary, PMD should be able to give the right number, this is
>>> something we can fix in idpf and cpfl PMD, to align with other PMD.
>>
>> Thanks Qi, Ok to have drivers aligned to common usage.
>>
>> Still, for telemetry we can consider removing 'rx_mbuf_alloc_fail', user
>> can get that information from 'rx_nombuf'.
>
> I would agree with Ferruh. The information on nombufs should be available
> just from the stats. It doesn't logically fit in the "info" category,
> especially when it is in stats already.
>
Thanks Bruce.
So, no need to update driver(s) related to 'rx_mbuf_alloc_fail',
existing patch is good.
I will send ethdev telemetry change later, it is a minor change.
