On 2024-01-19 18:43, Bruce Richardson wrote:
Update the device capability docs, to:
* include more cross-references
* split longer text into paragraphs, in most cases with each flag having
a single-line summary at the start of the doc block
* general comment rewording and clarification as appropriate
Signed-off-by: Bruce Richardson <bruce.richard...@intel.com>
---
lib/eventdev/rte_eventdev.h | 130 ++++++++++++++++++++++++++----------
1 file changed, 93 insertions(+), 37 deletions(-)
diff --git a/lib/eventdev/rte_eventdev.h b/lib/eventdev/rte_eventdev.h
index 949e957f1b..57a2791946 100644
--- a/lib/eventdev/rte_eventdev.h
+++ b/lib/eventdev/rte_eventdev.h
@@ -243,143 +243,199 @@ struct rte_event;
/* Event device capability bitmap flags */
#define RTE_EVENT_DEV_CAP_QUEUE_QOS (1ULL << 0)
/**< Event scheduling prioritization is based on the priority and weight
- * associated with each event queue. Events from a queue with highest priority
- * is scheduled first. If the queues are of same priority, weight of the queues
+ * associated with each event queue.
+ *
+ * Events from a queue with highest priority
+ * are scheduled first. If the queues are of same priority, weight of the
queues
* are considered to select a queue in a weighted round robin fashion.
* Subsequent dequeue calls from an event port could see events from the same
* event queue, if the queue is configured with an affinity count. Affinity
* count is the number of subsequent dequeue calls, in which an event port
* should use the same event queue if the queue is non-empty
*
Maybe the subject for a future documentation patch: but what happens to
order maintenance for different-priority events. I've always assumed
events on atomic/ordered queues where only ordered in the flow_id within
the same priority, not flow_id alone.
+ * NOTE: A device may use both queue prioritization and event prioritization
+ * (@ref RTE_EVENT_DEV_CAP_EVENT_QOS capability) when making packet scheduling
decisions.
+ *
* @see rte_event_queue_setup(), rte_event_queue_attr_set()
*/
#define RTE_EVENT_DEV_CAP_EVENT_QOS (1ULL << 1)
/**< Event scheduling prioritization is based on the priority associated with
- * each event. Priority of each event is supplied in *rte_event* structure
+ * each event.
+ *
+ * Priority of each event is supplied in *rte_event* structure
* on each enqueue operation.
+ * If this capability is not set, the priority field of the event structure
+ * is ignored for each event.
*
+ * NOTE: A device may use both queue prioritization (@ref
RTE_EVENT_DEV_CAP_QUEUE_QOS capability)
+ * and event prioritization when making packet scheduling decisions.
+
* @see rte_event_enqueue_burst()
*/
#define RTE_EVENT_DEV_CAP_DISTRIBUTED_SCHED (1ULL << 2)
/**< Event device operates in distributed scheduling mode.
+ *
* In distributed scheduling mode, event scheduling happens in HW or
- * rte_event_dequeue_burst() or the combination of these two.
+ * rte_event_dequeue_burst() / rte_event_enqueue_burst() or the combination of
these two.
* If the flag is not set then eventdev is centralized and thus needs a
* dedicated service core that acts as a scheduling thread .
*
- * @see rte_event_dequeue_burst()
+ * @see rte_event_dev_service_id_get
*/
#define RTE_EVENT_DEV_CAP_QUEUE_ALL_TYPES (1ULL << 3)
/**< Event device is capable of enqueuing events of any type to any queue.
+ *
* If this capability is not set, the queue only supports events of the
- * *RTE_SCHED_TYPE_* type that it was created with.
+ * *RTE_SCHED_TYPE_* type that it was created with.
+ * Any events of other types scheduled to the queue will handled in an
+ * implementation-dependent manner. They may be dropped by the
+ * event device, or enqueued with the scheduling type adjusted to the
+ * correct/supported value.
Having the application setting sched_type when it was already set on a
the level of the queue never made sense to me.
I can't see any reasons why this field shouldn't be ignored by the event
device on non-RTE_EVENT_QUEUE_CFG_ALL_TYPES queues.
If the behavior is indeed undefined, I think it's better to just say
"undefined" rather than the above speculation.
*
- * @see RTE_SCHED_TYPE_* values
+ * @see rte_event_enqueue_burst
+ * @see RTE_SCHED_TYPE_ATOMIC RTE_SCHED_TYPE_ORDERED RTE_SCHED_TYPE_PARALLEL
*/
#define RTE_EVENT_DEV_CAP_BURST_MODE (1ULL << 4)
/**< Event device is capable of operating in burst mode for enqueue(forward,
- * release) and dequeue operation. If this capability is not set, application
- * still uses the rte_event_dequeue_burst() and rte_event_enqueue_burst() but
- * PMD accepts only one event at a time.
+ * release) and dequeue operation.
+ *
+ * If this capability is not set, application
+ * can still use the rte_event_dequeue_burst() and rte_event_enqueue_burst()
but
+ * PMD accepts or returns only one event at a time.
*
* @see rte_event_dequeue_burst() rte_event_enqueue_burst()
*/
#define RTE_EVENT_DEV_CAP_IMPLICIT_RELEASE_DISABLE (1ULL << 5)
/**< Event device ports support disabling the implicit release feature, in
* which the port will release all unreleased events in its dequeue operation.
+ *
* If this capability is set and the port is configured with implicit release
* disabled, the application is responsible for explicitly releasing events
- * using either the RTE_EVENT_OP_FORWARD or the RTE_EVENT_OP_RELEASE event
+ * using either the @ref RTE_EVENT_OP_FORWARD or the @ref RTE_EVENT_OP_RELEASE
event
* enqueue operations.
*
* @see rte_event_dequeue_burst() rte_event_enqueue_burst()
*/
#define RTE_EVENT_DEV_CAP_NONSEQ_MODE (1ULL << 6)
-/**< Event device is capable of operating in none sequential mode. The path
- * of the event is not necessary to be sequential. Application can change
- * the path of event at runtime. If the flag is not set, then event each event
- * will follow a path from queue 0 to queue 1 to queue 2 etc. If the flag is
- * set, events may be sent to queues in any order. If the flag is not set, the
- * eventdev will return an error when the application enqueues an event for a
+/**< Event device is capable of operating in non-sequential mode.
+ *
+ * The path of the event is not necessary to be sequential. Application can
change
+ * the path of event at runtime and events may be sent to queues in any order.
+ *
+ * If the flag is not set, then event each event will follow a path from queue 0
+ * to queue 1 to queue 2 etc.
+ * The eventdev will return an error when the application enqueues an event
for a
* qid which is not the next in the sequence.
*/
#define RTE_EVENT_DEV_CAP_RUNTIME_PORT_LINK (1ULL << 7)
-/**< Event device is capable of configuring the queue/port link at runtime.
+/**< Event device is capable of reconfiguring the queue/port link at runtime.
+ *
* If the flag is not set, the eventdev queue/port link is only can be
- * configured during initialization.
+ * configured during initialization, or by stopping the device and
+ * then later restarting it after reconfiguration.
+ *
+ * @see rte_event_port_link rte_event_port_unlink
*/
#define RTE_EVENT_DEV_CAP_MULTIPLE_QUEUE_PORT (1ULL << 8)
-/**< Event device is capable of setting up the link between multiple queue
- * with single port. If the flag is not set, the eventdev can only map a
- * single queue to each port or map a single queue to many port.
+/**< Event device is capable of setting up links between multiple queues and a
single port.
+ *
+ * If the flag is not set, each port may only be linked to a single queue, and
+ * so can only receive events from that queue.
+ * However, each queue may be linked to multiple ports.
+ *
+ * @see rte_event_port_link
*/
#define RTE_EVENT_DEV_CAP_CARRY_FLOW_ID (1ULL << 9)
-/**< Event device preserves the flow ID from the enqueued
- * event to the dequeued event if the flag is set. Otherwise,
- * the content of this field is implementation dependent.
+/**< Event device preserves the flow ID from the enqueued event to the
dequeued event.
+ *
+ * If this flag is not set,
+ * the content of the flow-id field in dequeued events is implementation
dependent.
+ *
+ * @see rte_event_dequeue_burst
*/
#define RTE_EVENT_DEV_CAP_MAINTENANCE_FREE (1ULL << 10)
/**< Event device *does not* require calls to rte_event_maintain().
+ *
* An event device that does not set this flag requires calls to
* rte_event_maintain() during periods when neither
* rte_event_dequeue_burst() nor rte_event_enqueue_burst() are called
* on a port. This will allow the event device to perform internal
* processing, such as flushing buffered events, return credits to a
* global pool, or process signaling related to load balancing.
+ *
+ * @see rte_event_maintain
*/
#define RTE_EVENT_DEV_CAP_RUNTIME_QUEUE_ATTR (1ULL << 11)
/**< Event device is capable of changing the queue attributes at runtime i.e
- * after rte_event_queue_setup() or rte_event_start() call sequence. If this
- * flag is not set, eventdev queue attributes can only be configured during
+ * after rte_event_queue_setup() or rte_event_dev_start() call sequence.
+ *
+ * If this flag is not set, eventdev queue attributes can only be configured
during
* rte_event_queue_setup().
"event queue" or just "queue".
+ *
+ * @see rte_event_queue_setup
*/
#define RTE_EVENT_DEV_CAP_PROFILE_LINK (1ULL << 12)
-/**< Event device is capable of supporting multiple link profiles per event
port
- * i.e., the value of `rte_event_dev_info::max_profiles_per_port` is greater
- * than one.
+/**< Event device is capable of supporting multiple link profiles per event
port.
+ *
+ *
+ * When set, the value of `rte_event_dev_info::max_profiles_per_port` is
greater
+ * than one, and multiple profiles may be configured and then switched at
runtime.
+ * If not set, only a single profile may be configured, which may itself be
+ * runtime adjustable (if @ref RTE_EVENT_DEV_CAP_RUNTIME_PORT_LINK is set).
+ *
+ * @see rte_event_port_profile_links_set rte_event_port_profile_links_get
+ * @see rte_event_port_profile_switch
+ * @see RTE_EVENT_DEV_CAP_RUNTIME_PORT_LINK
*/
/* Event device priority levels */
#define RTE_EVENT_DEV_PRIORITY_HIGHEST 0
-/**< Highest priority expressed across eventdev subsystem
+/**< Highest priority expressed across eventdev subsystem.
"The highest priority an event device may support."
or
"The highest priority any event device may support."
Maybe this is a further improvement, beyond punctuation? "across
eventdev subsystem" sounds awkward.
+ *
* @see rte_event_queue_setup(), rte_event_enqueue_burst()
* @see rte_event_port_link()
*/
#define RTE_EVENT_DEV_PRIORITY_NORMAL 128
-/**< Normal priority expressed across eventdev subsystem
+/**< Normal priority expressed across eventdev subsystem.
+ *
* @see rte_event_queue_setup(), rte_event_enqueue_burst()
* @see rte_event_port_link()
*/
#define RTE_EVENT_DEV_PRIORITY_LOWEST 255
-/**< Lowest priority expressed across eventdev subsystem
+/**< Lowest priority expressed across eventdev subsystem.
+ *
* @see rte_event_queue_setup(), rte_event_enqueue_burst()
* @see rte_event_port_link()
*/
/* Event queue scheduling weights */
#define RTE_EVENT_QUEUE_WEIGHT_HIGHEST 255
-/**< Highest weight of an event queue
+/**< Highest weight of an event queue.
+ *
* @see rte_event_queue_attr_get(), rte_event_queue_attr_set()
*/
#define RTE_EVENT_QUEUE_WEIGHT_LOWEST 0
-/**< Lowest weight of an event queue
+/**< Lowest weight of an event queue.
+ *
* @see rte_event_queue_attr_get(), rte_event_queue_attr_set()
*/
/* Event queue scheduling affinity */
#define RTE_EVENT_QUEUE_AFFINITY_HIGHEST 255
-/**< Highest scheduling affinity of an event queue
+/**< Highest scheduling affinity of an event queue.
+ *
* @see rte_event_queue_attr_get(), rte_event_queue_attr_set()
*/
#define RTE_EVENT_QUEUE_AFFINITY_LOWEST 0
-/**< Lowest scheduling affinity of an event queue
+/**< Lowest scheduling affinity of an event queue.
+ *
* @see rte_event_queue_attr_get(), rte_event_queue_attr_set()
*/
