Re: [dpdk-dev] [RFC V2 1/2] app/testpmd: fix queue stats mapping configuration

["Min Hu (Connor)" <humin29@huawei.com>]

Hi Ferruh, any suggestions?


在 2020/11/3 14:30, Min Hu (Connor) 写道:
> Hi Ferruh,
> 
> I agree with your proposal. But if we remove record structures, we will
> not be able to query the current queue stats mapping configuration. Or
> we can provide a query API for the PMD driver that uses the
> set_queue_stats_mapping API, and driver records these mapping
> information from user.
> 
> What do you think?
> 
> 
> 在 2020/10/31 4:54, Ferruh Yigit 写道:
>> On 10/20/2020 9:26 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) There is no need to keep cache line alignment for
>>> 'struct queue_stats_mappings'.
>>> 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) The configuration result does not take effect or can not be queried
>>> in real time.
>>>
>>> Therefore, we have made the following adjustments:
>>> 1) If PMD supports queue stats mapping, configure to driver in real time
>>> after executing the command "set stat_qmap rx/tx ...". If not,
>>> the command can not be accepted.
>>> 2) Only display queues that mapping done by adding a new 'active' field
>>>   in queue_stats_mappings struct.
>>> 3) Remove cache alignment for 'struct queue_stats_mappings'.
>>> 4) Add a new port_stats_mappings struct in rte_port.
>>> The struct contains number of rx/txq stats mapping, rx/tx
>>> queue_stats_mapping_enabled flag, and rx/tx queue_stats_mapping array.
>>> Size of queue_stats_mapping_array is set to 
>>> "RTE_ETHDEV_QUEUE_STAT_CNTRS"
>>>   to ensure that the same number of queues can be set for each port.
>>>
>>
>> Hi Connor,
>>
>> I think above adjustment are good, but after the decision to use 
>> xstats for the queue stats, what do you think about more simplification,
>>
>> 1)
>> What testpmd does is, records the queue stats mapping commands and 
>> registers them later on port start & forwarding start.
>> What happens if recording and registering completely removed?
>> When "set stat_qmap .." issued, it just call the ethdev APIs to do the 
>> mapping in device.
>> This lets us removing record structures, "struct port_stats_mappings 
>> p_stats_map"
>> Also can remove 'map_port_queue_stats_mapping_registers()' and its sub 
>> functions.
>>
>> 2)
>> Also lets remove "tx-queue-stats-mapping" & "rx-queue-stats-mapping" 
>> parameters, which enables removing 
>> 'parse_queue_stats_mapping_config()' function too
>>
>> 3)
>> Another problem is to display the queue stats, in 
>> 'fwd_stats_display()' & 'nic_stats_display()', there is a check if the 
>> queue stats mapping enable or not ('rx_queue_stats_mapping_enabled' & 
>> 'tx_queue_stats_mapping_enabled'),
>> I think displaying queue stats and queue stat mapping should be 
>> separate, why not drop checks for queue stats mapping and display 
>> queue stats for 'nb_rxq' & 'nb_txq' queues?
>>
>> Does above make sense?
>>
>>
>> Majority of the drivers doesn't require queue stat mapping to get the 
>> queue stats, lets don't pollute main usage with this requirement.
>>
>>
>>> 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>
>>
>> <...>
>>
>> .