RE: [RFC PATCH] eventdev: adapter API to configure multiple Rx queues

[Shijith Thotton <sthotton@marvell.com>]

Hi @Naga Harish K, S V,

>>> This RFC introduces a new API, rte_event_eth_rx_adapter_queues_add(),
>>> designed to enhance the flexibility of configuring multiple Rx queues in
>>> eventdev Rx adapter.
>>>
>>> The existing rte_event_eth_rx_adapter_queue_add() API supports adding
>>> multiple queues by specifying rx_queue_id = -1, but it lacks the ability to
>apply
>>> specific configurations to each of the added queues.
>>>
>>
>>The application can still use the existing
>>rte_event_eth_rx_adapter_queue_add() API
>>in a loop with different configurations for different queues.
>>
>>The proposed API is not enabling new features that cannot be achieved with
>>the existing API.
>>Adding new APIs without much usefulness causes unnecessary
>>complexity/confusion for users.
>>
>
>The new API was introduced because the existing API does not support adding
>multiple
>queues with specific configurations. It serves as a burst variant of the existing
>API,
>like many other APIs in DPDK.
>
>For better clarity, the API can be renamed to
>rte_event_eth_rx_adapter_queue_add_burst() if needed.
>
>In hardware, adding each queue individually incurs significant overheads, such
>as
>mailbox operations. A burst API helps to amortize this overhead. Since real-
>world
>applications often call the API with specific queue_ids, the burst API can
>provide
>considerable benefits. Testing shows a 75% reduction in time when adding
>multiple
>queues to the RX adapter using the burst API on our platform.
>
>I can modify the old API implementation to act as a wrapper around the burst
>API,
>with number of queues equal to 1. If concerns remain, we can explore
>deprecation
>as an alternative.
>

Please let me know if you have any suggestions/feedback on what I said above.
If not, I can go ahead and send v1.

Thanks,
Shijith

>>> The proposed API, rte_event_eth_rx_adapter_queues_add, addresses this
>>> limitation by:
>>>
>>> - Enabling users to specify an array of rx_queue_id values alongside
>>>   individual configurations for each queue.
>>>
>>> - Supporting a nb_rx_queues argument to define the number of queues to
>>>   configure. When set to 0, the API applies a common configuration to
>>>   all queues, similar to the existing rx_queue_id = -1 behavior.
>>>
>>> This enhancement allows for more granular control when configuring
>multiple
>>> Rx queues. Additionally, the API can act as a replacement for the older API,
>>> offering both flexibility and improved functionality.
>>>
>>> Signed-off-by: Shijith Thotton <sthotton@marvell.com>
>>> ---
>>>  lib/eventdev/eventdev_pmd.h             | 34 +++++++++++++++++++++++++
>>>  lib/eventdev/rte_event_eth_rx_adapter.h | 34
>>> +++++++++++++++++++++++++
>>>  2 files changed, 68 insertions(+)
>>>
>>> diff --git a/lib/eventdev/eventdev_pmd.h b/lib/eventdev/eventdev_pmd.h
>>> index 36148f8d86..2e458a9779 100644
>>> --- a/lib/eventdev/eventdev_pmd.h
>>> +++ b/lib/eventdev/eventdev_pmd.h
>>> @@ -25,6 +25,7 @@
>>>  #include <rte_mbuf_dyn.h>
>>>
>>>  #include "event_timer_adapter_pmd.h"
>>> +#include "rte_event_eth_rx_adapter.h"
>>>  #include "rte_eventdev.h"
>>>
>>>  #ifdef __cplusplus
>>> @@ -708,6 +709,37 @@ typedef int
>>> (*eventdev_eth_rx_adapter_queue_add_t)(
>>>  		int32_t rx_queue_id,
>>>  		const struct rte_event_eth_rx_adapter_queue_conf
>>> *queue_conf);
>>>
>>> +/**
>>> + * Add ethernet Rx queues to event device. This callback is invoked if
>>> + * the caps returned from rte_eventdev_eth_rx_adapter_caps_get(,
>>> +eth_port_id)
>>> + * has RTE_EVENT_ETH_RX_ADAPTER_CAP_INTERNAL_PORT set.
>>> + *
>>> + * @param dev
>>> + *   Event device pointer
>>> + *
>>> + * @param eth_dev
>>> + *   Ethernet device pointer
>>> + *
>>> + * @param rx_queue_id
>>> + *   Ethernet device receive queue index array
>>> + *
>>> + * @param queue_conf
>>> + *   Additional configuration structure array
>>> + *
>>> + * @param nb_rx_queues
>>> + *   Number of ethernet device receive queues
>>> + *
>>> + * @return
>>> + *   - 0: Success, ethernet receive queues added successfully.
>>> + *   - <0: Error code returned by the driver function.
>>> + */
>>> +typedef int (*eventdev_eth_rx_adapter_queues_add_t)(
>>> +		const struct rte_eventdev *dev,
>>> +		const struct rte_eth_dev *eth_dev,
>>> +		int32_t rx_queue_id[],
>>> +		const struct rte_event_eth_rx_adapter_queue_conf
>>> queue_conf[],
>>> +		uint16_t nb_rx_queues);
>>> +
>>>  /**
>>>   * Delete ethernet Rx queues from event device. This callback is invoked if
>>>   * the caps returned from eventdev_eth_rx_adapter_caps_get(,
>eth_port_id)
>>> @@ -1578,6 +1610,8 @@ struct eventdev_ops {
>>>  	/**< Get ethernet Rx adapter capabilities */
>>>  	eventdev_eth_rx_adapter_queue_add_t eth_rx_adapter_queue_add;
>>>  	/**< Add Rx queues to ethernet Rx adapter */
>>> +	eventdev_eth_rx_adapter_queues_add_t
>>> eth_rx_adapter_queues_add;
>>> +	/**< Add Rx queues to ethernet Rx adapter */
>>>  	eventdev_eth_rx_adapter_queue_del_t eth_rx_adapter_queue_del;
>>>  	/**< Delete Rx queues from ethernet Rx adapter */
>>>  	eventdev_eth_rx_adapter_queue_conf_get_t
>>> eth_rx_adapter_queue_conf_get; diff --git
>>> a/lib/eventdev/rte_event_eth_rx_adapter.h
>>> b/lib/eventdev/rte_event_eth_rx_adapter.h
>>> index 9237e198a7..9a5c560b67 100644
>>> --- a/lib/eventdev/rte_event_eth_rx_adapter.h
>>> +++ b/lib/eventdev/rte_event_eth_rx_adapter.h
>>> @@ -553,6 +553,40 @@ int rte_event_eth_rx_adapter_queue_add(uint8_t
>>> id,
>>>  			int32_t rx_queue_id,
>>>  			const struct rte_event_eth_rx_adapter_queue_conf
>>> *conf);
>>>
>>> +/**
>>> + * Add multiple receive queues to an event adapter.
>>> + *
>>> + * @param id
>>> + *  Adapter identifier.
>>> + *
>>> + * @param eth_dev_id
>>> + *  Port identifier of Ethernet device.
>>> + *
>>> + * @param rx_queue_id
>>> + *  Array of Ethernet device receive queue indices.
>>> + *  If nb_rx_queues is 0, then rx_queue_id is ignored.
>>> + *
>>> + * @param conf
>>> + *  Array of additional configuration structures of type
>>> + *  *rte_event_eth_rx_adapter_queue_conf*. conf[i] is used for
>>> rx_queue_id[i].
>>> + *  If nb_rx_queues is 0, then conf[0] is used for all Rx queues.
>>> + *
>>> + * @param nb_rx_queues
>>> + *  Number of receive queues to add.
>>> + *  If nb_rx_queues is 0, then all Rx queues configured for
>>> + *  the device are added with the same configuration in conf[0].
>>> + * @see RTE_EVENT_ETH_RX_ADAPTER_CAP_MULTI_EVENTQ
>>> + *
>>> + * @return
>>> + *  - 0: Success, Receive queues added correctly.
>>> + *  - <0: Error code on failure.
>>> + */
>>> +__rte_experimental
>>> +int rte_event_eth_rx_adapter_queues_add(
>>> +			uint8_t id, uint16_t eth_dev_id, int32_t
>>> rx_queue_id[],
>>> +			const struct rte_event_eth_rx_adapter_queue_conf
>>> conf[],
>>> +			uint16_t nb_rx_queues);
>>> +
>>>  /**
>>>   * Delete receive queue from an event adapter.
>>>   *
>>> --
>>> 2.25.1