RE: [PATCH v6 2/3] eventdev: add support for independent enqueue

["Pathak, Pravin" <pravin.pathak@intel.com>]

> On 2024-07-11 21:54, Abdullah Sevincer wrote:
> > This commit adds support for independent enqueue feature and updates
> > Event Device and PMD feature list.
> >
> > A new capability RTE_EVENT_DEV_CAP_INDEPENDENT_ENQ is introduced to
> > support independent enqueue to support PMD to enqueue in any order
> > even the underlined hardware device needs enqueues in a strict dequeue
> > order.
> >
> > To use this capability applications need to set flag
> > RTE_EVENT_PORT_CFG_INDEPENDENT_ENQ during port setup only if the
> > capability RTE_EVENT_DEV_CAP_INDEPENDENT_ENQ exists.
> >
> > Signed-off-by: Abdullah Sevincer <abdullah.sevincer@intel.com>
> > ---
> >   doc/guides/eventdevs/features/default.ini |  1 +
> >   doc/guides/eventdevs/features/dlb2.ini    |  1 +
> >   doc/guides/rel_notes/release_24_07.rst    |  5 ++++
> >   lib/eventdev/rte_eventdev.h               | 36 +++++++++++++++++++++++
> >   4 files changed, 43 insertions(+)
> >
> > diff --git a/doc/guides/eventdevs/features/default.ini
> > b/doc/guides/eventdevs/features/default.ini
> > index 1cc4303fe5..7c4ee99238 100644
> > --- a/doc/guides/eventdevs/features/default.ini
> > +++ b/doc/guides/eventdevs/features/default.ini
> > @@ -22,6 +22,7 @@ carry_flow_id              =
> >   maintenance_free           =
> >   runtime_queue_attr         =
> >   profile_links              =
> > +independent_enq            =
> >
> >   ;
> >   ; Features of a default Ethernet Rx adapter.
> > diff --git a/doc/guides/eventdevs/features/dlb2.ini
> > b/doc/guides/eventdevs/features/dlb2.ini
> > index 7b80286927..c7193b47c1 100644
> > --- a/doc/guides/eventdevs/features/dlb2.ini
> > +++ b/doc/guides/eventdevs/features/dlb2.ini
> > @@ -15,6 +15,7 @@ implicit_release_disable   = Y
> >   runtime_port_link          = Y
> >   multiple_queue_port        = Y
> >   maintenance_free           = Y
> > +independent_enq            = Y
> >
> >   [Eth Rx adapter Features]
> >
> > diff --git a/doc/guides/rel_notes/release_24_07.rst
> > b/doc/guides/rel_notes/release_24_07.rst
> > index 76a79093d1..d8564b19f0 100644
> > --- a/doc/guides/rel_notes/release_24_07.rst
> > +++ b/doc/guides/rel_notes/release_24_07.rst
> > @@ -162,6 +162,11 @@ New Features
> >     ``RTE_EVENT_PORT_CFG_INDEPENDENT_ENQ`` to enable the feature if the
> capability
> >     ``RTE_EVENT_DEV_CAP_INDEPENDENT_ENQ`` exists.
> >
> > +* **Updated Event Device Library for independent enqueue feature**
> > +
> > +  * Added support for independent enqueue feature. Updated Event Device
> and
> > +    PMD feature list.
> > +
> >
> >   Removed Items
> >   -------------
> > diff --git a/lib/eventdev/rte_eventdev.h b/lib/eventdev/rte_eventdev.h
> > index 08e5f9320b..462fc3f18f 100644
> > --- a/lib/eventdev/rte_eventdev.h
> > +++ b/lib/eventdev/rte_eventdev.h
> > @@ -446,6 +446,30 @@ struct rte_event;
> >    * @see RTE_SCHED_TYPE_PARALLEL
> >    */
> >
> > +#define RTE_EVENT_DEV_CAP_INDEPENDENT_ENQ  (1ULL << 16) /**< Event
> > +device is capable of independent enqueue.
> > + * A new capability, RTE_EVENT_DEV_CAP_INDEPENDENT_ENQ, will indicate
> > +that Eventdev
> > + * supports the enqueue in any order or specifically in a different
> > +order than the
> > + * dequeue. Eventdev PMD can either transmit events in the changed
> > +order in which
> > + * they are enqueued or restore the original order before sending
> > +them to the
> > + * underlying hardware device. A flag is provided during the port
> > +configuration to
> > + * inform Eventdev PMD that the application intends to use an
> > +independent enqueue
> > + * order on a particular port. Note that this capability only matters
> > +for Eventdevs
> > + * supporting burst mode.
> > + *
> > + * To Inform PMD that the application plans to use independent
> > +enqueue order on a port
> > + * this code example can be used:
> > + *
> > + *  if (capability & RTE_EVENT_DEV_CAP_INDEPENDENT_ENQ)
> > + *     port_config = port_config |
> RTE_EVENT_PORT_CFG_INDEPENDENT_ENQ;
> > + *
> > + * When an implicit release is enabled on a port, Eventdev PMD will
> > +also handle
> > + * the insertion of RELEASE events in place of dropped events. The
> > +order restoration
> 
> "The independent enqueue feature only applies to /../" maybe?
> 
> > + * only applies to FORWARD and RELEASE events. New events
> > + (op=RTE_EVENT_OP_NEW) will
> > + * be transmitted in the order the application enqueues them. New
> > + events do not
> > + * maintain any order relative to FORWARD/RELEASE events.
> 
> Is FORWARD<->NEW relaxed ordering specific to ports which has enabled
> RTE_EVENT_PORT_CFG_INDEPENDENT_ENQ?

Yes. Relaxed ordering only applies to ports with independent enqueue enabled.
We will update the documentation. 

> If not, that information should probably be somewhere else.
> 
> Either way,
> Reviewed-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
> 
> > + */
> > +
> >   /* Event device priority levels */
> >   #define RTE_EVENT_DEV_PRIORITY_HIGHEST   0
> >   /**< Highest priority level for events and queues.
> > @@ -1072,6 +1096,18 @@ rte_event_queue_attr_set(uint8_t dev_id, uint8_t
> queue_id, uint32_t attr_id,
> >    *
> >    *  @see rte_event_port_setup()
> >    */
> > + #define RTE_EVENT_PORT_CFG_INDEPENDENT_ENQ   (1ULL << 5)
> > +/**< Flag to enable independent enqueue. Must not be set if the
> > +device
> > + * is not RTE_EVENT_DEV_CAP_INDEPENDENT_ENQ capable. This feature
> > + * allows an application to enqueue RTE_EVENT_OP_FORWARD or
> > + * RTE_EVENT_OP_RELEASE in an order different than the order the
> > + * events were dequeued from the event device, while maintaining
> > + * RTE_SCHED_TYPE_ATOMIC or RTE_SCHED_TYPE_ORDERED semantics.
> > + *
> > + * Note that this flag only matters for Eventdevs supporting burst mode.
> > + *
> > + *  @see rte_event_port_setup()
> > + */
> >
> >   /** Event port configuration structure */
> >   struct rte_event_port_conf {