Re: [dpdk-dev] [RFC V4] app/testpmd: fix queue stats mapping configuration

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

On 11/30/2020 8:29 AM, Min Hu (Connor) wrote:
> Hi, Ferruh, and all,
>      are there any comments about this set of patch?
> 

I am good with this one, would you mind sending an actual patch (not RFC) on top 
of the latest head?

Thanks,
ferruh

> 在 2020/11/23 17:51, Ferruh Yigit 写道:
>> On 11/21/2020 4:29 AM, Stephen Hemminger wrote:
>>> On Fri, 20 Nov 2020 23:33:40 +0000
>>> Ferruh Yigit <ferruh.yigit@intel.com> wrote:
>>>
>>>> On 11/20/2020 11:21 PM, Stephen Hemminger wrote:
>>>>> On Fri, 20 Nov 2020 17:26:55 +0000
>>>>> Ferruh Yigit <ferruh.yigit@intel.com> wrote:
>>>>>> On 11/20/2020 11:50 AM, Min Hu (Connor) wrote:
>>>>>>> From: Huisong Li <lihuisong@huawei.com>
>>>>>>>
>>>>>>> Currently, the queue stats mapping has the following problems:
>>>>>>> 1) Many PMD drivers don't support queue stats mapping. But there is no
>>>>>>>     failure message after executing the command "set stat_qmap rx 0 2 2".
>>>>>>> 2) Once queue mapping is set, unrelated and unmapped queues are also
>>>>>>> displayed.
>>>>>>> 3) The configuration result does not take effect or can not be queried
>>>>>>> in real time.
>>>>>>> 4) The mapping arrays, "tx_queue_stats_mappings_array" &
>>>>>>> "rx_queue_stats_mappings_array" are global and their sizes are based on
>>>>>>> fixed max port and queue size assumptions.
>>>>>>> 5) These record structures, 'map_port_queue_stats_mapping_registers()'
>>>>>>>     and its sub functions are redundant for majority of drivers.
>>>>>>> 6) The display of the queue stats and queue stats mapping is mixed
>>>>>>>     together.
>>>>>>>
>>>>>>> Since xstats is used to obtain queue statistics, we have made the following
>>>>>>>     simplifications and adjustments:
>>>>>>> 1) If PMD requires and supports queue stats mapping, configure to driver in
>>>>>>>     real time by calling ethdev API after executing the command
>>>>>>>     "set stat_qmap rx/tx ...". If not, the command can not be accepted.
>>>>>>> 2) Based on the above adjustments, these record structures,
>>>>>>> 'map_port_queue_stats_mapping_registers()' and its sub functions can be
>>>>>>>     removed. "tx-queue-stats-mapping" & "rx-queue-stats-mapping" parameters,
>>>>>>>     and 'parse_queue_stats_mapping_config()' can be removed too.
>>>>>>> 3) remove display of queue stats mapping in 'fwd_stats_display()' &
>>>>>>>     'nic_stats_display()', and obtain queue stats by xstats.
>>>>>>>     Since the record structures are removed, 'nic_stats_mapping_display()'
>>>>>>>     can be deleted.
>>>>>>>
>>>>>>> Fixes: 4dccdc789bf4b ("app/testpmd: simplify handling of stats mappings 
>>>>>>> error")
>>>>>>> Fixes: 013af9b6b64f6 ("app/testpmd: various updates")
>>>>>>> Fixes: ed30d9b691b21 ("app/testpmd: add stats per queue")
>>>>>>>
>>>>>>> Signed-off-by: Huisong Li <lihuisong@huawei.com>
>>>>>>
>>>>>> Overall    looks good to me.
>>>>>> I did a quick test didn't see anything unexpected. 'xstats' or 
>>>>>> 'dpdk-proc-info'
>>>>>> app still can be used to get queue stats and "set stat_qmap ..." is 
>>>>>> working as
>>>>>> expected.
>>>>>>
>>>>>> But it is a little late for this release cycle, would you be OK to get 
>>>>>> this at
>>>>>> the beginning of next release?
>>>>>
>>>>> Could we plan to deprecate queue stats mapping in future when xstats work 
>>>>> is done?
>>>>
>>>> Even queue stats moved to xstats, a few PMDs still need this configuration 
>>>> and API.
>>>> And this patch already cleans the queue stats mapping noise from testpmd.
>>>>
>>>> What is the benefit/motivation to deprecate the queue stats mapping API?
>>>
>>> Mostly because so few drivers implement it, that any application using it
>>> is  going to be non-portable.
>>>
>>
>> 'rte_eth_dev_set_.*_queue_stats_mapping()' APIs return '-ENOTSUP' if 
>> underlying PMD doesn't support it, applications can check this for portable code.
>> .