#define DSW_PMD_NAME RTE_STR(event_dsw)
-/* Code changes are required to allow more ports. */
#define DSW_MAX_PORTS (64)
#define DSW_MAX_PORT_DEQUEUE_DEPTH (128)
#define DSW_MAX_PORT_ENQUEUE_DEPTH (128)
+#define DSW_MAX_PORT_OUT_BUFFER (32)
#define DSW_MAX_QUEUES (16)
#define DSW_MAX_EVENTS (16384)
-/* Code changes are required to allow more flows than 32k. */
-#define DSW_MAX_FLOWS_BITS (15)
+/* Multiple 24-bit flow ids will map to the same DSW-level flow. The
+ * number of DSW flows should be high enough make it unlikely that
+ * flow ids of several large flows hash to the same DSW-level flow.
+ * Such collisions will limit parallism and thus the number of cores
+ * that may be utilized. However, configuring a large number of DSW
+ * flows might potentially, depending on traffic and actual
+ * application flow id value range, result in each such DSW-level flow
+ * being very small. The effect of migrating such flows will be small,
+ * in terms amount of processing load redistributed. This will in turn
+ * reduce the load balancing speed, since flow migration rate has an
+ * upper limit. Code changes are required to allow > 32k DSW-level
+ * flows.
+ */
+#define DSW_MAX_FLOWS_BITS (13)
#define DSW_MAX_FLOWS (1<<(DSW_MAX_FLOWS_BITS))
#define DSW_MAX_FLOWS_MASK (DSW_MAX_FLOWS-1)
+/* Eventdev RTE_SCHED_TYPE_PARALLEL doesn't have a concept of flows,
+ * but the 'dsw' scheduler (more or less) randomly assign flow id to
+ * events on parallel queues, to be able to reuse some of the
+ * migration mechanism and scheduling logic from
+ * RTE_SCHED_TYPE_ATOMIC. By moving one of the parallel "flows" from a
+ * particular port, the likely-hood of events being scheduled to this
+ * port is reduced, and thus a kind of statistical load balancing is
+ * achieved.
+ */
+#define DSW_PARALLEL_FLOWS (1024)
+
+/* 'Background tasks' are polling the control rings for *
+ * migration-related messages, or flush the output buffer (so
+ * buffered events doesn't linger too long). Shouldn't be too low,
+ * since the system won't benefit from the 'batching' effects from
+ * the output buffer, and shouldn't be too high, since it will make
+ * buffered events linger too long in case the port goes idle.
+ */
+#define DSW_MAX_PORT_OPS_PER_BG_TASK (128)
+
+/* Avoid making small 'loans' from the central in-flight event credit
+ * pool, to improve efficiency.
+ */
+#define DSW_MIN_CREDIT_LOAN (64)
+#define DSW_PORT_MAX_CREDITS (2*DSW_MIN_CREDIT_LOAN)
+#define DSW_PORT_MIN_CREDITS (DSW_MIN_CREDIT_LOAN)
+
/* The rings are dimensioned so that all in-flight events can reside
* on any one of the port rings, to avoid the trouble of having to
* care about the case where there's no room on the destination port's
*/
#define DSW_IN_RING_SIZE (DSW_MAX_EVENTS)
+#define DSW_MAX_LOAD (INT16_MAX)
+#define DSW_LOAD_FROM_PERCENT(x) ((int16_t)(((x)*DSW_MAX_LOAD)/100))
+#define DSW_LOAD_TO_PERCENT(x) ((100*x)/DSW_MAX_LOAD)
+
+/* The thought behind keeping the load update interval shorter than
+ * the migration interval is that the load from newly migrated flows
+ * should 'show up' on the load measurement before new migrations are
+ * considered. This is to avoid having too many flows, from too many
+ * source ports, to be migrated too quickly to a lightly loaded port -
+ * in particular since this might cause the system to oscillate.
+ */
+#define DSW_LOAD_UPDATE_INTERVAL (DSW_MIGRATION_INTERVAL/4)
+#define DSW_OLD_LOAD_WEIGHT (1)
+
+/* The minimum time (in us) between two flow migrations. What puts an
+ * upper limit on the actual migration rate is primarily the pace in
+ * which the ports send and receive control messages, which in turn is
+ * largely a function of how much cycles are spent the processing of
+ * an event burst.
+ */
+#define DSW_MIGRATION_INTERVAL (1000)
+#define DSW_MIN_SOURCE_LOAD_FOR_MIGRATION (DSW_LOAD_FROM_PERCENT(70))
+#define DSW_MAX_TARGET_LOAD_FOR_MIGRATION (DSW_LOAD_FROM_PERCENT(95))
+#define DSW_REBALANCE_THRESHOLD (DSW_LOAD_FROM_PERCENT(3))
+
+#define DSW_MAX_EVENTS_RECORDED (128)
+
+#define DSW_MAX_FLOWS_PER_MIGRATION (8)
+
+/* Only one outstanding migration per port is allowed */
+#define DSW_MAX_PAUSED_FLOWS (DSW_MAX_PORTS*DSW_MAX_FLOWS_PER_MIGRATION)
+
+/* Enough room for paus request/confirm and unpaus request/confirm for
+ * all possible senders.
+ */
+#define DSW_CTL_IN_RING_SIZE ((DSW_MAX_PORTS-1)*4)
+
+/* With DSW_SORT_DEQUEUED enabled, the scheduler will, at the point of
+ * dequeue(), arrange events so that events with the same flow id on
+ * the same queue forms a back-to-back "burst", and also so that such
+ * bursts of different flow ids, but on the same queue, also come
+ * consecutively. All this in an attempt to improve data and
+ * instruction cache usage for the application, at the cost of a
+ * scheduler overhead increase.
+ */
+
+/* #define DSW_SORT_DEQUEUED */
+
+struct dsw_queue_flow {
+ uint8_t queue_id;
+ uint16_t flow_hash;
+};
+
+enum dsw_migration_state {
+ DSW_MIGRATION_STATE_IDLE,
+ DSW_MIGRATION_STATE_PAUSING,
+ DSW_MIGRATION_STATE_FORWARDING,
+ DSW_MIGRATION_STATE_UNPAUSING
+};
+
struct dsw_port {
uint16_t id;
uint16_t dequeue_depth;
uint16_t enqueue_depth;
+ int32_t inflight_credits;
+
int32_t new_event_threshold;
+ uint16_t pending_releases;
+
+ uint16_t next_parallel_flow_id;
+
+ uint16_t ops_since_bg_task;
+
+ /* most recent 'background' processing */
+ uint64_t last_bg;
+
+ /* For port load measurement. */
+ uint64_t next_load_update;
+ uint64_t load_update_interval;
+ uint64_t measurement_start;
+ uint64_t busy_start;
+ uint64_t busy_cycles;
+ uint64_t total_busy_cycles;
+
+ /* For the ctl interface and flow migration mechanism. */
+ uint64_t next_emigration;
+ uint64_t migration_interval;
+ enum dsw_migration_state migration_state;
+
+ uint64_t emigration_start;
+ uint64_t emigrations;
+ uint64_t emigration_latency;
+
+ uint8_t emigration_target_port_ids[DSW_MAX_FLOWS_PER_MIGRATION];
+ struct dsw_queue_flow
+ emigration_target_qfs[DSW_MAX_FLOWS_PER_MIGRATION];
+ uint8_t emigration_targets_len;
+ uint8_t cfm_cnt;
+
+ uint64_t immigrations;
+
+ uint16_t paused_flows_len;
+ struct dsw_queue_flow paused_flows[DSW_MAX_PAUSED_FLOWS];
+
+ /* In a very contrived worst case all inflight events can be
+ * laying around paused here.
+ */
+ uint16_t paused_events_len;
+ struct rte_event paused_events[DSW_MAX_EVENTS];
+
+ uint16_t seen_events_len;
+ uint16_t seen_events_idx;
+ struct dsw_queue_flow seen_events[DSW_MAX_EVENTS_RECORDED];
+
+ uint64_t enqueue_calls;
+ uint64_t new_enqueued;
+ uint64_t forward_enqueued;
+ uint64_t release_enqueued;
+ uint64_t queue_enqueued[DSW_MAX_QUEUES];
+
+ uint64_t dequeue_calls;
+ uint64_t dequeued;
+ uint64_t queue_dequeued[DSW_MAX_QUEUES];
+
+ uint16_t out_buffer_len[DSW_MAX_PORTS];
+ struct rte_event out_buffer[DSW_MAX_PORTS][DSW_MAX_PORT_OUT_BUFFER];
+
+ uint16_t in_buffer_len;
+ uint16_t in_buffer_start;
+ /* This buffer may contain events that were read up from the
+ * in_ring during the flow migration process.
+ */
+ struct rte_event in_buffer[DSW_MAX_EVENTS];
+
struct rte_event_ring *in_ring __rte_cache_aligned;
+
+ struct rte_ring *ctl_in_ring __rte_cache_aligned;
+
+ /* Estimate of current port load. */
+ rte_atomic16_t load __rte_cache_aligned;
+ /* Estimate of flows currently migrating to this port. */
+ rte_atomic32_t immigration_load __rte_cache_aligned;
} __rte_cache_aligned;
struct dsw_queue {
uint8_t schedule_type;
uint8_t serving_ports[DSW_MAX_PORTS];
uint16_t num_serving_ports;
+
+ uint8_t flow_to_port_map[DSW_MAX_FLOWS] __rte_cache_aligned;
};
struct dsw_evdev {
uint16_t num_ports;
struct dsw_queue queues[DSW_MAX_QUEUES];
uint8_t num_queues;
+ int32_t max_inflight;
+
+ rte_atomic32_t credits_on_loan __rte_cache_aligned;
};
+#define DSW_CTL_PAUS_REQ (0)
+#define DSW_CTL_UNPAUS_REQ (1)
+#define DSW_CTL_CFM (2)
+
+struct dsw_ctl_msg {
+ uint8_t type;
+ uint8_t originating_port_id;
+ uint8_t qfs_len;
+ struct dsw_queue_flow qfs[DSW_MAX_FLOWS_PER_MIGRATION];
+} __rte_aligned(4);
+
+uint16_t dsw_event_enqueue(void *port, const struct rte_event *event);
+uint16_t dsw_event_enqueue_burst(void *port,
+ const struct rte_event events[],
+ uint16_t events_len);
+uint16_t dsw_event_enqueue_new_burst(void *port,
+ const struct rte_event events[],
+ uint16_t events_len);
+uint16_t dsw_event_enqueue_forward_burst(void *port,
+ const struct rte_event events[],
+ uint16_t events_len);
+
+uint16_t dsw_event_dequeue(void *port, struct rte_event *ev, uint64_t wait);
+uint16_t dsw_event_dequeue_burst(void *port, struct rte_event *events,
+ uint16_t num, uint64_t wait);
+
+int dsw_xstats_get_names(const struct rte_eventdev *dev,
+ enum rte_event_dev_xstats_mode mode,
+ uint8_t queue_port_id,
+ struct rte_event_dev_xstats_name *xstats_names,
+ unsigned int *ids, unsigned int size);
+int dsw_xstats_get(const struct rte_eventdev *dev,
+ enum rte_event_dev_xstats_mode mode, uint8_t queue_port_id,
+ const unsigned int ids[], uint64_t values[], unsigned int n);
+uint64_t dsw_xstats_get_by_name(const struct rte_eventdev *dev,
+ const char *name, unsigned int *id);
+
static inline struct dsw_evdev *
dsw_pmd_priv(const struct rte_eventdev *eventdev)
{
return eventdev->data->dev_private;
}
+#define DSW_LOG_DP(level, fmt, args...) \
+ RTE_LOG_DP(level, EVENTDEV, "[%s] %s() line %u: " fmt, \
+ DSW_PMD_NAME, \
+ __func__, __LINE__, ## args)
+
+#define DSW_LOG_DP_PORT(level, port_id, fmt, args...) \
+ DSW_LOG_DP(level, "<Port %d> " fmt, port_id, ## args)
+
#endif