[dpdk-dev] [v1] ethdev: support Tx queue used count

[Ferruh Yigit]

On 1/12/2024 12:29 PM, Morten Brørup wrote:
>> From: Ferruh Yigit [mailto:ferruh.yigit at amd.com]
>> Sent: Friday, 12 January 2024 12.34
>>
>> On 1/11/2024 3:17 PM, jerinj at marvell.com wrote:
>>> From: Jerin Jacob <jerinj at marvell.com>
>>>
>>> Introduce a new API to retrieve the number of used descriptors
>>> in a Tx queue. Applications can leverage this API in the fast path to
>>> inspect the Tx queue occupancy and take appropriate actions based on
>> the
>>> available free descriptors.
>>>
>>> A notable use case could be implementing Random Early Discard (RED)
>>> in software based on Tx queue occupancy.

<...>

>>>  /**
>>>   * @internal
>>>   * Structure used to hold opaque pointers to internal ethdev Rx/Tx
>>> @@ -116,7 +119,9 @@ struct rte_eth_fp_ops {
>>>  	eth_tx_descriptor_status_t tx_descriptor_status;
>>>  	/** Copy used mbufs from Tx mbuf ring into Rx. */
>>>  	eth_recycle_tx_mbufs_reuse_t recycle_tx_mbufs_reuse;
>>> -	uintptr_t reserved2[2];
>>> +	/** Get the number of used Tx descriptors. */
>>> +	eth_tx_queue_count_t tx_queue_count;
>>>
>>
>> Similarly, can you please move it above 'tx_descriptor_status'?
> 
> No. I think struct rte_eth_fp_ops is part of the public API, so moving down tx_descriptor_status and recycle_tx_mbufs_reuse would break the API.
> 

ack (Dave highlighted the same)