Re: [PATCH] ethdev: introduce ethdev dump API

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

Hi,

在 2022/2/8 20:59, Ferruh Yigit 写道:
> On 2/8/2022 11:14 AM, Min Hu (Connor) wrote:
>> Hi, Ferruh,
>>
>> 在 2022/2/8 18:21, Ferruh Yigit 写道:
>>> On 2/8/2022 12:39 AM, Min Hu (Connor) wrote:
>>>> Hi, Ferruh,
>>>>
>>>> 在 2022/2/7 23:35, Ferruh Yigit 写道:
>>>>> On 2/7/2022 12:56 PM, Morten Brørup wrote:
>>>>>>> From: Ferruh Yigit [mailto:ferruh.yigit@intel.com]
>>>>>>> Sent: Monday, 7 February 2022 13.36
>>>>>>>
>>>>>>> On 2/7/2022 12:18 PM, Morten Brørup wrote:
>>>>>>>>> From: Ferruh Yigit [mailto:ferruh.yigit@intel.com]
>>>>>>>>> Sent: Monday, 7 February 2022 12.46
>>>>>>>>>
>>>>>>>>> On 2/7/2022 1:47 AM, Min Hu (Connor) wrote:
>>>>>>>>>> Added the ethdev dump API which provides functions for query
>>>>>>> private
>>>>>>>>> info
>>>>>>>>>
>>>>>>>>> Isn't API and function are same thing in this contexts?
>>>>>>>>>
>>>>>>>>>> from device. There exists many private properties in different 
>>>>>>>>>> PMD
>>>>>>>>> drivers,
>>>>>>>>>> such as adapter state, Rx/Tx func algorithm in hns3 PMD. The
>>>>>>>>> information of
>>>>>>>>>> these properties is important for debug. As the information is
>>>>>>>>> private,
>>>>>>>>>> the new API is introduced.>
>>>>>>>>>
>>>>>>>>> In the patch title 'ethdev' is duplicated, can you fix it?
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
>>>>>>>>>> Acked-by: Morten Brørup <mb@smartsharesystems.com>
>>>>>>>>>> Acked-by: Ray Kinsella <mdr@ashroe.eu>
>>>>>>>>>> Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
>>>>>>>>
>>>>>>>> [...]
>>>>>>>>
>>>>>>>>>> @@ -990,6 +990,20 @@ typedef int
>>>>>>> (*eth_representor_info_get_t)(struct
>>>>>>>>> rte_eth_dev *dev,
>>>>>>>>>>     typedef int (*eth_rx_metadata_negotiate_t)(struct rte_eth_dev
>>>>>>> *dev,
>>>>>>>>>>                            uint64_t *features);
>>>>>>>>>>
>>>>>>>>>> +/**
>>>>>>>>>> + * @internal
>>>>>>>>>> + * Dump ethdev private info to a file.
>>>>>>>>>> + *
>>>>>>>>>
>>>>>>>>> It doesn't dump the 'ethdev' private info, it dumps the private 
>>>>>>>>> info
>>>>>>>>> from device.
>>>>>>>>
>>>>>>>> It seems perfectly clear to me. How would you prefer it phrased
>>>>>>> instead?
>>>>>>>>
>>>>>>>
>>>>>>> What described in the document is more accurate,
>>>>>>> "query private info from device".
>>>>>>>
>>>>>>> What we are dumping here is not ethdev private info, it is device
>>>>>>> private info,
>>>>
>>>> what is the difference between ethdev and device?
>>>
>>> It is not very clear, but for me 'ethdev' is refers to device abstract
>>> layer (ethdev library) specific private data 
>> Could you give an example for 'ethdev'specific private data ?
>>
> 
> I think 'struct rte_eth_dev' content can be a sample.
> 
> But I hear you, diff is not clear, it is subtle as Morten said,
> when doc and commit log refers it as "private info from device",
> I think we can use the same in the API documentation as well.
> 
Agreed， I will fix it in release_22_03.rst.
>> and device refers to ethdev
>>> device (PMD) private data. ethdev is common for all drivers.
>> OK, we could treat it as convention in future.
>>>
>>>>>>> and we really don't know what that data may be in the ethdev layer.
>>>>>>>
>>>>>>> Also there is a chance that 'ethdev private info' can be confused 
>>>>>>> with
>>>>>>> 'ethdev->data->dev_private'
>>>> what I want to dump is exactly the 'ethdev->data->dev_private'.
>>>> 'ethdev private info' means 'ethdev->data->dev_private'.
>>>> why confused?
>>>
>>> What I understand was this API can return any device private 
>>> information,
>>> it is not limited to 'ethdev->data->dev_private', (although most of the 
>> I think this API is limited to 'ethdev->data->dev_private'.
>>> data
>>> is represented in this struct), like if you want to dump queue state,
>>> this is out of 'ethdev->data->dev_private'.
>> Queue state can be dumped using API 'rte_eth_tx_queue_info_get'.
>>
> 
> Yes it can be. But as far as I can see there is nothing prevents the dump()
> API to provide the same, it is up to PMD.
> 
> If the intention is to limit what can be dump to 
> 'ethdev->data->dev_private',
> it is not clear from API documentation/implementation.
> 
>>>
>>>>>>
>>>>>> OK. Now I got your point! The difference is very subtle.
>>>>>>
>>>>>>>
>>>>>>>> [...]
>>>>>>>>
>>>>>>>>>
>>>>>>>>>> + */
>>>>>>>>>> +__rte_experimental
>>>>>>>>>> +int rte_eth_dev_priv_dump(FILE *file, uint16_t port_id);
>>>>>>>>>> +
>>>>>>>>>
>>>>>>>>> What do you think to have the 'port_id' as first argument to be
>>>>>>>>> consistent
>>>>>>>>> with the other APIs?
>>>>>>>>
>>>>>>>> The _dump APIs in other libraries have the file pointer as the 
>>>>>>>> first
>>>>>>> parameter, so let's follow that convention here too. No need to move
>>>>>>> the port_id parameter here.
>>>>>>>>
>>>>>>>
>>>>>>> Yes, for most of the _dump() APIs, file pointer seems is the first
>>>>>>> argument,
>>>>>>> bu they are from various libraries.
>>>>>>>
>>>>>>> Within the ethdev APIs, I think it makes sense that all APIs 
>>>>>>> start with
>>>>>>> 'port_id' parameter for consistency, like done in:
>>>>>>> rte_flow_dev_dump(uint16_t port_id, ...)
>>>>>>>
>>>>>>>> Only rte_dma_dump() has the file pointer last, and I didn't 
>>>>>>>> catch it
>>>>>>> when the function was defined.
>>>>>>>>
>>>>>>
>>>>>> OK. Then I agree with you about following the convention like 
>>>>>> rte_flow_dev_dump() with the port_id first.
>>>>>>
>>>>>> I even think Connor got it right the first time, and I proposed 
>>>>>> following the other convention.
>>>>>>
>>>>>
>>>>> Ahh, may bad I missed that, sorry for not commenting on time.
>>>>>
>>>>>
>>>>>> It's not easy when there are two opposite conventions. :-)
>>>>>>
>>>>>
>>>>> Yep, that is the main issue.
>>>>>
>>>>> .
>>>
>>> .
> 
> .