Re: [dpdk-dev] [PATCH V5] ethdev: add queue state when retrieve queue information

["Kinsella, Ray" <mdr@ashroe.eu>]

On 23/04/2021 12:26, Ananyev, Konstantin wrote:
> 
> 
>> -----Original Message-----
>> From: dev <dev-bounces@dpdk.org> On Behalf Of Kinsella, Ray
>> Sent: Friday, April 23, 2021 12:17 PM
>> To: Lijun Ou <oulijun@huawei.com>; thomas@monjalon.net; Yigit, Ferruh <ferruh.yigit@intel.com>
>> Cc: dev@dpdk.org; linuxarm@openeuler.org
>> Subject: Re: [dpdk-dev] [PATCH V5] ethdev: add queue state when retrieve queue information
>>
>>
>>
>> On 17/04/2021 04:09, Lijun Ou wrote:
>>> Currently, upper-layer application could get queue state only
>>> through pointers such as dev->data->tx_queue_state[queue_id],
>>> this is not the recommended way to access it. So this patch
>>> add get queue state when call rte_eth_rx_queue_info_get and
>>> rte_eth_tx_queue_info_get API.
>>>
>>> Note: After add queue_state field, the 'struct rte_eth_rxq_info' size
>>> remains 128B, and the 'struct rte_eth_txq_info' size remains 64B, so
>>> it could be ABI compatible.
>>>
>>> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
>>> Signed-off-by: Lijun Ou <oulijun@huawei.com>
>>> Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
>>> ---
>>> V4->V5:
>>> - Add acked-by
>>> - add a note to the "New features" section to annouce the new feature.
>>>
>>> V3->V4:
>>> - update libabigail.abignore for removing the CI warnings
>>>
>>> V2->V3:
>>> - rewrite the commit log and delete the part Note
>>> - rewrite tht comments for queue state
>>> - move the queue_state definition locations
>>>
>>> V1->V2:
>>> - move queue state defines to public file
>>> ---
>>>  doc/guides/rel_notes/release_21_05.rst | 6 ++++++
>>>  lib/librte_ethdev/ethdev_driver.h      | 7 -------
>>>  lib/librte_ethdev/rte_ethdev.c         | 3 +++
>>>  lib/librte_ethdev/rte_ethdev.h         | 9 +++++++++
>>>  4 files changed, 18 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/doc/guides/rel_notes/release_21_05.rst b/doc/guides/rel_notes/release_21_05.rst
>>> index 58272e1..1ab3681 100644
>>> --- a/doc/guides/rel_notes/release_21_05.rst
>>> +++ b/doc/guides/rel_notes/release_21_05.rst
>>> @@ -81,6 +81,12 @@ New Features
>>>        representor=[[c#]pf#]sf# sf[0,2-1023] /* 1023 SFs.                     */
>>>        representor=[c#]pf#      c2pf[0,1]    /* 2 PFs on controller 2.        */
>>>
>>> +* **Enhanced function for getting rxq/txq info ABI.**
>>> +  * Added new field ``queue_state`` to ``rte_eth_rxq_info`` structure to
>>> +    provide indicated rxq queue state.
>>> +  * Added new field ``queue_state`` to ``rte_eth_txq_info`` structure to
>>> +    provide indicated txq queue state.
>>> +
>>>  * **Added support for meter PPS profile.**
>>>
>>>    Currently meter algorithms only supports bytes per second(BPS).
>>> diff --git a/lib/librte_ethdev/ethdev_driver.h b/lib/librte_ethdev/ethdev_driver.h
>>> index 113129d..40e474a 100644
>>> --- a/lib/librte_ethdev/ethdev_driver.h
>>> +++ b/lib/librte_ethdev/ethdev_driver.h
>>> @@ -952,13 +952,6 @@ struct eth_dev_ops {
>>>  };
>>>
>>>  /**
>>> - * RX/TX queue states
>>> - */
>>> -#define RTE_ETH_QUEUE_STATE_STOPPED 0
>>> -#define RTE_ETH_QUEUE_STATE_STARTED 1
>>> -#define RTE_ETH_QUEUE_STATE_HAIRPIN 2
>>> -
>>> -/**
>>>   * @internal
>>>   * Check if the selected Rx queue is hairpin queue.
>>>   *
>>> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
>>> index c73d263..d5adf4f 100644
>>> --- a/lib/librte_ethdev/rte_ethdev.c
>>> +++ b/lib/librte_ethdev/rte_ethdev.c
>>> @@ -5038,6 +5038,8 @@ rte_eth_rx_queue_info_get(uint16_t port_id, uint16_t queue_id,
>>>
>>>  	memset(qinfo, 0, sizeof(*qinfo));
>>>  	dev->dev_ops->rxq_info_get(dev, queue_id, qinfo);
>>> +	qinfo->queue_state = dev->data->rx_queue_state[queue_id];
>>> +
>>>  	return 0;
>>>  }
>>>
>>> @@ -5078,6 +5080,7 @@ rte_eth_tx_queue_info_get(uint16_t port_id, uint16_t queue_id,
>>>
>>>  	memset(qinfo, 0, sizeof(*qinfo));
>>>  	dev->dev_ops->txq_info_get(dev, queue_id, qinfo);
>>> +	qinfo->queue_state = dev->data->tx_queue_state[queue_id];
>>>
>>>  	return 0;
>>>  }
>>> diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
>>> index 3b773b6..a0d01d2 100644
>>> --- a/lib/librte_ethdev/rte_ethdev.h
>>> +++ b/lib/librte_ethdev/rte_ethdev.h
>>> @@ -1588,6 +1588,13 @@ struct rte_eth_dev_info {
>>>  };
>>>
>>>  /**
>>> + * RX/TX queue states
>>> + */
>>> +#define RTE_ETH_QUEUE_STATE_STOPPED 0
>>> +#define RTE_ETH_QUEUE_STATE_STARTED 1
>>> +#define RTE_ETH_QUEUE_STATE_HAIRPIN 2
>>> +
>>> +/**
>>>   * Ethernet device RX queue information structure.
>>>   * Used to retrieve information about configured queue.
>>>   */
>>> @@ -1595,6 +1602,7 @@ struct rte_eth_rxq_info {
>>>  	struct rte_mempool *mp;     /**< mempool used by that queue. */
>>>  	struct rte_eth_rxconf conf; /**< queue config parameters. */
>>>  	uint8_t scattered_rx;       /**< scattered packets RX supported. */
>>> +	uint8_t queue_state;        /**< one of RTE_ETH_QUEUE_STATE_*. */
>>
>> Are we sure this is a false positive? - it is being added mid-structure on the rx-side at least.
>> Shouldn't this be appended to the end - unless it is being sneaked into padding between fields.
> 
> I believe there was a padding, that's why it was suggested to squeeze it here.

Yes - I took a look with pahole after reading back in the thread a bit,
where Thomas points out the 1byte padding hole in memory we could use.
Good work, as it avoids having to rework the structure at the next ABI version. 

>>
>>>  	uint16_t nb_desc;           /**< configured number of RXDs. */
>>>  	uint16_t rx_buf_size;       /**< hardware receive buffer size. */
>>>  } __rte_cache_min_aligned;
>>> @@ -1606,6 +1614,7 @@ struct rte_eth_rxq_info {
>>>  struct rte_eth_txq_info {
>>>  	struct rte_eth_txconf conf; /**< queue config parameters. */
>>>  	uint16_t nb_desc;           /**< configured number of TXDs. */
>>> +	uint8_t queue_state;        /**< one of RTE_ETH_QUEUE_STATE_*. */
>>>  } __rte_cache_min_aligned;
>>>
>>>  /* Generic Burst mode flag definition, values can be ORed. */
>>>