[PATCH v9 0/6] Introduce event pre-scheduling

[Jerin Jacob]

On Tue, Oct 8, 2024 at 3:14 AM <pbhagavatula at marvell.com> wrote:
>
> From: Pavan Nikhilesh <pbhagavatula at marvell.com>
>
> Event pre-scheduling improves scheduling performance by assigning events
> to event ports in advance when dequeues are issued.
> This series introduces various types and levels of pre-scheduling to the
> eventdev library.
>
> pre-scheduling Types:
>  * RTE_EVENT_PRESCHEDULE_NONE: No pre-scheduling.
>  * RTE_EVENT_PRESCHEDULE: Always issue a pre-schedule when dequeue is issued.
>  * RTE_EVENT_PRESCHEDULE_ADAPTIVE: Delay issuing pre-schedule until there
>    are no forward progress constraints with the held flow contexts.
>
> pre-scheduling Levels:
>  * Event Device Level Pre-scheduling: Pre-scheduling can be enabled or disabled at the
>    event device during configuration. Event devices can indicate pre-scheduling
>    capabilities using `RTE_EVENT_DEV_CAP_EVENT_PRESCHEDULE` and
>   `RTE_EVENT_DEV_CAP_EVENT_PRESCHEDULE_ADAPTIVE` via the event device info
>   function `info.event_dev_cap`.
>  * Event Port Level Prefetch: Pre-scheduling can be selectively enabled or disabled
>    at the event port during runtime. Event devices can indicate this capability
>    using `RTE_EVENT_PORT_CAP_PER_PORT_PRESCHEDULE` via the event device info
>    function `info.event_port_cap`.
>  * Application Controlled Prefetch Hint: Applications can provide hints to the
>    event device to start pre-scheduling events using the new API
>    `rte_event_port_pre-schedule`. Event devices can indicate this capabilities using
>    `RTE_EVENT_DEV_CAP_PRESCHEDULE_EXPLICIT` via the event device info function
>    `info.event_dev_cap`.
>
> The rte_event_dequeue_burst operation initiates the pre-schedule operation, which
> completes in parallel without affecting the flow context of the dequeued events and
> dequeue latency. On the next dequeue operation, the pre-scheduleed events are
> dequeued, and pre-schedule operation is initiated again.
>
> In the case of application-controlled pre-schedule hints, the currently held flow
> contexts, if any, are not affected by the pre-schedule operation. On the next
> dequeue operation, the pre-scheduleed events are returned, but pre-schedule is not
> initiated again until the application provides the hint again. If pre-scheduling
> is already enabled at the event device level or event port level, the hint is ignored.
>
> v2 Changes:
> - s/prefetch/pre-schedule (Mattias).
> v3 Changes:
> - Add CNXK preschedule implementation.
> - Update test-eventdev to use prescheduling.
> - Update examples to use prescheduling.
> v4 Changes:
> - Fix compilation.
> v5 Changes:
> - Update ABI changes
> - s/RTE_EVENT_DEV_PRESCHEDULE/RTE_EVENT_PRESCHEDULE/
> - s/RTE_EVENT_DEV_CAP_SW_PRESCHEDULE/RTE_EVENT_DEV_CAP_PRESCHEDULE_EXPLICIT/
> - s/RTE_EVENT_PORT_CAP_EVENT_PER_PORT_PRESCHEDULE/RTE_EVENT_PORT_CAP_PER_PORT_PRESCHEDULE
> - Various documentation fixes and updates.
> v6 Changes:
> - Mark new APIs as experimental (Stephen).
> v7 Changes:
> - Use correct patchset for rebase.
> v8 Changes:
> - fix checkpatch issues.
> v9 Changes:
> - Rebase update capability bits, fix release notes format.


Series-Acked-by: Jerin Jacob <jerinj at marvell.com>

Series applied to dpdk-next-net-eventdev/for-main. Thanks