Re: [dpdk-dev] [PATCH 01/27] eventdev: dlb upstream prerequisites

[Jerin Jacob <jerinjacobk@gmail.com>]

> +
> +/** Event port configuration structure */
> +struct rte_event_port_conf_v20 {
> +       int32_t new_event_threshold;
> +       /**< A backpressure threshold for new event enqueues on this port.
> +        * Use for *closed system* event dev where event capacity is limited,
> +        * and cannot exceed the capacity of the event dev.
> +        * Configuring ports with different thresholds can make higher priority
> +        * traffic less likely to  be backpressured.
> +        * For example, a port used to inject NIC Rx packets into the event dev
> +        * can have a lower threshold so as not to overwhelm the device,
> +        * while ports used for worker pools can have a higher threshold.
> +        * This value cannot exceed the *nb_events_limit*
> +        * which was previously supplied to rte_event_dev_configure().
> +        * This should be set to '-1' for *open system*.
> +        */
> +       uint16_t dequeue_depth;
> +       /**< Configure number of bulk dequeues for this event port.
> +        * This value cannot exceed the *nb_event_port_dequeue_depth*
> +        * which previously supplied to rte_event_dev_configure().
> +        * Ignored when device is not RTE_EVENT_DEV_CAP_BURST_MODE capable.
> +        */
> +       uint16_t enqueue_depth;
> +       /**< Configure number of bulk enqueues for this event port.
> +        * This value cannot exceed the *nb_event_port_enqueue_depth*
> +        * which previously supplied to rte_event_dev_configure().
> +        * Ignored when device is not RTE_EVENT_DEV_CAP_BURST_MODE capable.
> +        */
>         uint8_t disable_implicit_release;
>         /**< Configure the port not to release outstanding events in
>          * rte_event_dev_dequeue_burst(). If true, all events received through
> @@ -733,6 +911,14 @@ struct rte_event_port_conf {
>  rte_event_port_default_conf_get(uint8_t dev_id, uint8_t port_id,
>                                 struct rte_event_port_conf *port_conf);
>
> +int
> +rte_event_port_default_conf_get_v20(uint8_t dev_id, uint8_t port_id,
> +                               struct rte_event_port_conf_v20 *port_conf);
> +
> +int
> +rte_event_port_default_conf_get_v21(uint8_t dev_id, uint8_t port_id,
> +                                     struct rte_event_port_conf *port_conf);

Hi Timothy,

+ ABI Maintainers (Ray, Neil)

# As per my understanding, the structures can not be versioned, only
function can be versioned.
i.e we can not make any change to " struct rte_event_port_conf"

# We have a similar case with ethdev and it deferred to next release v20.11
http://patches.dpdk.org/patch/69113/

Regarding the API changes:
# The slow path changes general looks good to me. I will review the
next level in the coming days
# The following fast path changes bothers to me. Could you share more
details on below change?

diff --git a/app/test-eventdev/test_order_atq.c
b/app/test-eventdev/test_order_atq.c
index 3366cfc..8246b96 100644
--- a/app/test-eventdev/test_order_atq.c
+++ b/app/test-eventdev/test_order_atq.c
@@ -34,6 +34,8 @@
                        continue;
                }

+               ev.flow_id = ev.mbuf->udata64;
+
# Since RC1 is near, I am not sure how to accommodate the API changes
now and sort out ABI stuffs.
# Other concern is eventdev spec get bloated with versioning files
just for ONE release as 20.11 will be OK to change the ABI.
# While we discuss the API change, Please send deprecation notice for
ABI change for 20.11,
so that there is no ambiguity of this patch for the 20.11 release.