diff --git a/drivers/event/dsw/Makefile b/drivers/event/dsw/Makefile index 5cbf488ff8..6374a454e0 100644 --- a/drivers/event/dsw/Makefile +++ b/drivers/event/dsw/Makefile @@ -21,6 +21,6 @@ LIBABIVER := 1 EXPORT_MAP := rte_pmd_dsw_event_version.map -SRCS-$(CONFIG_RTE_LIBRTE_PMD_DSW_EVENTDEV) += dsw_evdev.c +SRCS-$(CONFIG_RTE_LIBRTE_PMD_DSW_EVENTDEV) += dsw_evdev.c dsw_event.c include $(RTE_SDK)/mk/rte.lib.mk diff --git a/drivers/event/dsw/dsw_evdev.c b/drivers/event/dsw/dsw_evdev.c index 5dccc232a4..40a7435be6 100644 --- a/drivers/event/dsw/dsw_evdev.c +++ b/drivers/event/dsw/dsw_evdev.c @@ -6,6 +6,7 @@ #include #include +#include #include "dsw_evdev.h" @@ -201,10 +202,125 @@ dsw_configure(const struct rte_eventdev *dev) { struct dsw_evdev *dsw = dsw_pmd_priv(dev); const struct rte_event_dev_config *conf = &dev->data->dev_conf; + int32_t min_max_in_flight; dsw->num_ports = conf->nb_event_ports; dsw->num_queues = conf->nb_event_queues; + /* Avoid a situation where consumer ports are holding all the + * credits, without making use of them. + */ + min_max_in_flight = conf->nb_event_ports * DSW_PORT_MAX_CREDITS; + + dsw->max_inflight = RTE_MAX(conf->nb_events_limit, min_max_in_flight); + + return 0; +} + + +static void +initial_flow_to_port_assignment(struct dsw_evdev *dsw) +{ + uint8_t queue_id; + for (queue_id = 0; queue_id < dsw->num_queues; queue_id++) { + struct dsw_queue *queue = &dsw->queues[queue_id]; + uint16_t flow_hash; + for (flow_hash = 0; flow_hash < DSW_MAX_FLOWS; flow_hash++) { + uint8_t port_idx = + rte_rand() % queue->num_serving_ports; + uint8_t port_id = + queue->serving_ports[port_idx]; + dsw->queues[queue_id].flow_to_port_map[flow_hash] = + port_id; + } + } +} + +static int +dsw_start(struct rte_eventdev *dev) +{ + struct dsw_evdev *dsw = dsw_pmd_priv(dev); + + rte_atomic32_init(&dsw->credits_on_loan); + + initial_flow_to_port_assignment(dsw); + + return 0; +} + +static void +dsw_port_drain_buf(uint8_t dev_id, struct rte_event *buf, uint16_t buf_len, + eventdev_stop_flush_t flush, void *flush_arg) +{ + uint16_t i; + + for (i = 0; i < buf_len; i++) + flush(dev_id, buf[i], flush_arg); +} + +static void +dsw_port_drain_out(uint8_t dev_id, struct dsw_evdev *dsw, struct dsw_port *port, + eventdev_stop_flush_t flush, void *flush_arg) +{ + uint16_t dport_id; + + for (dport_id = 0; dport_id < dsw->num_ports; dport_id++) + if (dport_id != port->id) + dsw_port_drain_buf(dev_id, port->out_buffer[dport_id], + port->out_buffer_len[dport_id], + flush, flush_arg); +} + +static void +dsw_port_drain_in_ring(uint8_t dev_id, struct dsw_port *port, + eventdev_stop_flush_t flush, void *flush_arg) +{ + struct rte_event ev; + + while (rte_event_ring_dequeue_burst(port->in_ring, &ev, 1, NULL)) + flush(dev_id, ev, flush_arg); +} + +static void +dsw_drain(uint8_t dev_id, struct dsw_evdev *dsw, + eventdev_stop_flush_t flush, void *flush_arg) +{ + uint16_t port_id; + + if (flush == NULL) + return; + + for (port_id = 0; port_id < dsw->num_ports; port_id++) { + struct dsw_port *port = &dsw->ports[port_id]; + + dsw_port_drain_out(dev_id, dsw, port, flush, flush_arg); + dsw_port_drain_in_ring(dev_id, port, flush, flush_arg); + } +} + +static void +dsw_stop(struct rte_eventdev *dev) +{ + struct dsw_evdev *dsw = dsw_pmd_priv(dev); + uint8_t dev_id; + eventdev_stop_flush_t flush; + void *flush_arg; + + dev_id = dev->data->dev_id; + flush = dev->dev_ops->dev_stop_flush; + flush_arg = dev->data->dev_stop_flush_arg; + + dsw_drain(dev_id, dsw, flush, flush_arg); +} + +static int +dsw_close(struct rte_eventdev *dev) +{ + struct dsw_evdev *dsw = dsw_pmd_priv(dev); + + dsw->num_ports = 0; + dsw->num_queues = 0; + return 0; } @@ -219,6 +335,9 @@ static struct rte_eventdev_ops dsw_evdev_ops = { .port_unlink = dsw_port_unlink, .dev_infos_get = dsw_info_get, .dev_configure = dsw_configure, + .dev_start = dsw_start, + .dev_stop = dsw_stop, + .dev_close = dsw_close }; static int @@ -236,6 +355,12 @@ dsw_probe(struct rte_vdev_device *vdev) return -EFAULT; dev->dev_ops = &dsw_evdev_ops; + dev->enqueue = dsw_event_enqueue; + dev->enqueue_burst = dsw_event_enqueue_burst; + dev->enqueue_new_burst = dsw_event_enqueue_new_burst; + dev->enqueue_forward_burst = dsw_event_enqueue_forward_burst; + dev->dequeue = dsw_event_dequeue; + dev->dequeue_burst = dsw_event_dequeue_burst; if (rte_eal_process_type() != RTE_PROC_PRIMARY) return 0; diff --git a/drivers/event/dsw/dsw_evdev.h b/drivers/event/dsw/dsw_evdev.h index ad0f857cc9..f8e94e4a4e 100644 --- a/drivers/event/dsw/dsw_evdev.h +++ b/drivers/event/dsw/dsw_evdev.h @@ -14,6 +14,7 @@ #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) @@ -24,6 +25,24 @@ #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) + +/* 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 @@ -44,8 +63,17 @@ struct dsw_port { 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 out_buffer_len[DSW_MAX_PORTS]; + struct rte_event out_buffer[DSW_MAX_PORTS][DSW_MAX_PORT_OUT_BUFFER]; + struct rte_event_ring *in_ring __rte_cache_aligned; } __rte_cache_aligned; @@ -53,6 +81,8 @@ 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 { @@ -62,12 +92,38 @@ 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; }; +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); + 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, " " fmt, port_id, ## args) + #endif diff --git a/drivers/event/dsw/dsw_event.c b/drivers/event/dsw/dsw_event.c new file mode 100644 index 0000000000..4a3af8ecd0 --- /dev/null +++ b/drivers/event/dsw/dsw_event.c @@ -0,0 +1,359 @@ +/* SPDX-License-Identifier: BSD-3-Clause + * Copyright(c) 2018 Ericsson AB + */ + +#include "dsw_evdev.h" + +#include + +#include +#include + +static bool +dsw_port_acquire_credits(struct dsw_evdev *dsw, struct dsw_port *port, + int32_t credits) +{ + int32_t inflight_credits = port->inflight_credits; + int32_t missing_credits = credits - inflight_credits; + int32_t total_on_loan; + int32_t available; + int32_t acquired_credits; + int32_t new_total_on_loan; + + if (likely(missing_credits <= 0)) { + port->inflight_credits -= credits; + return true; + } + + total_on_loan = rte_atomic32_read(&dsw->credits_on_loan); + available = dsw->max_inflight - total_on_loan; + acquired_credits = RTE_MAX(missing_credits, DSW_PORT_MIN_CREDITS); + + if (available < acquired_credits) + return false; + + /* This is a race, no locks are involved, and thus some other + * thread can allocate tokens in between the check and the + * allocation. + */ + new_total_on_loan = rte_atomic32_add_return(&dsw->credits_on_loan, + acquired_credits); + + if (unlikely(new_total_on_loan > dsw->max_inflight)) { + /* Some other port took the last credits */ + rte_atomic32_sub(&dsw->credits_on_loan, acquired_credits); + return false; + } + + DSW_LOG_DP_PORT(DEBUG, port->id, "Acquired %d tokens from pool.\n", + acquired_credits); + + port->inflight_credits += acquired_credits; + port->inflight_credits -= credits; + + return true; +} + +static void +dsw_port_return_credits(struct dsw_evdev *dsw, struct dsw_port *port, + int32_t credits) +{ + port->inflight_credits += credits; + + if (unlikely(port->inflight_credits > DSW_PORT_MAX_CREDITS)) { + int32_t leave_credits = DSW_PORT_MIN_CREDITS; + int32_t return_credits = + port->inflight_credits - leave_credits; + + port->inflight_credits = leave_credits; + + rte_atomic32_sub(&dsw->credits_on_loan, return_credits); + + DSW_LOG_DP_PORT(DEBUG, port->id, + "Returned %d tokens to pool.\n", + return_credits); + } +} + +static uint8_t +dsw_schedule(struct dsw_evdev *dsw, uint8_t queue_id, uint16_t flow_hash) +{ + struct dsw_queue *queue = &dsw->queues[queue_id]; + uint8_t port_id; + + if (queue->num_serving_ports > 1) + port_id = queue->flow_to_port_map[flow_hash]; + else + /* A single-link queue, or atomic/ordered/parallel but + * with just a single serving port. + */ + port_id = queue->serving_ports[0]; + + DSW_LOG_DP(DEBUG, "Event with queue_id %d flow_hash %d is scheduled " + "to port %d.\n", queue_id, flow_hash, port_id); + + return port_id; +} + +static void +dsw_port_transmit_buffered(struct dsw_evdev *dsw, struct dsw_port *source_port, + uint8_t dest_port_id) +{ + struct dsw_port *dest_port = &(dsw->ports[dest_port_id]); + uint16_t *buffer_len = &source_port->out_buffer_len[dest_port_id]; + struct rte_event *buffer = source_port->out_buffer[dest_port_id]; + uint16_t enqueued = 0; + + if (*buffer_len == 0) + return; + + /* The rings are dimensioned to fit all in-flight events (even + * on a single ring), so looping will work. + */ + do { + enqueued += + rte_event_ring_enqueue_burst(dest_port->in_ring, + buffer+enqueued, + *buffer_len-enqueued, + NULL); + } while (unlikely(enqueued != *buffer_len)); + + (*buffer_len) = 0; +} + +static uint16_t +dsw_port_get_parallel_flow_id(struct dsw_port *port) +{ + uint16_t flow_id = port->next_parallel_flow_id; + + port->next_parallel_flow_id = + (port->next_parallel_flow_id + 1) % DSW_PARALLEL_FLOWS; + + return flow_id; +} + +static void +dsw_port_buffer_non_paused(struct dsw_evdev *dsw, struct dsw_port *source_port, + uint8_t dest_port_id, const struct rte_event *event) +{ + struct rte_event *buffer = source_port->out_buffer[dest_port_id]; + uint16_t *buffer_len = &source_port->out_buffer_len[dest_port_id]; + + if (*buffer_len == DSW_MAX_PORT_OUT_BUFFER) + dsw_port_transmit_buffered(dsw, source_port, dest_port_id); + + buffer[*buffer_len] = *event; + + (*buffer_len)++; +} + +#define DSW_FLOW_ID_BITS (24) +static uint16_t +dsw_flow_id_hash(uint32_t flow_id) +{ + uint16_t hash = 0; + uint16_t offset = 0; + + do { + hash ^= ((flow_id >> offset) & DSW_MAX_FLOWS_MASK); + offset += DSW_MAX_FLOWS_BITS; + } while (offset < DSW_FLOW_ID_BITS); + + return hash; +} + +static void +dsw_port_buffer_parallel(struct dsw_evdev *dsw, struct dsw_port *source_port, + struct rte_event event) +{ + uint8_t dest_port_id; + + event.flow_id = dsw_port_get_parallel_flow_id(source_port); + + dest_port_id = dsw_schedule(dsw, event.queue_id, + dsw_flow_id_hash(event.flow_id)); + + dsw_port_buffer_non_paused(dsw, source_port, dest_port_id, &event); +} + +static void +dsw_port_buffer_event(struct dsw_evdev *dsw, struct dsw_port *source_port, + const struct rte_event *event) +{ + uint16_t flow_hash; + uint8_t dest_port_id; + + if (unlikely(dsw->queues[event->queue_id].schedule_type == + RTE_SCHED_TYPE_PARALLEL)) { + dsw_port_buffer_parallel(dsw, source_port, *event); + return; + } + + flow_hash = dsw_flow_id_hash(event->flow_id); + + dest_port_id = dsw_schedule(dsw, event->queue_id, flow_hash); + + dsw_port_buffer_non_paused(dsw, source_port, dest_port_id, event); +} + +static void +dsw_port_flush_out_buffers(struct dsw_evdev *dsw, struct dsw_port *source_port) +{ + uint16_t dest_port_id; + + for (dest_port_id = 0; dest_port_id < dsw->num_ports; dest_port_id++) + dsw_port_transmit_buffered(dsw, source_port, dest_port_id); +} + +uint16_t +dsw_event_enqueue(void *port, const struct rte_event *ev) +{ + return dsw_event_enqueue_burst(port, ev, unlikely(ev == NULL) ? 0 : 1); +} + +static __rte_always_inline uint16_t +dsw_event_enqueue_burst_generic(void *port, const struct rte_event events[], + uint16_t events_len, bool op_types_known, + uint16_t num_new, uint16_t num_release, + uint16_t num_non_release) +{ + struct dsw_port *source_port = port; + struct dsw_evdev *dsw = source_port->dsw; + bool enough_credits; + uint16_t i; + + DSW_LOG_DP_PORT(DEBUG, source_port->id, "Attempting to enqueue %d " + "events to port %d.\n", events_len, source_port->id); + + /* XXX: For performance (=ring efficiency) reasons, the + * scheduler relies on internal non-ring buffers instead of + * immediately sending the event to the destination ring. For + * a producer that doesn't intend to produce or consume any + * more events, the scheduler provides a way to flush the + * buffer, by means of doing an enqueue of zero events. In + * addition, a port cannot be left "unattended" (e.g. unused) + * for long periods of time, since that would stall + * migration. Eventdev API extensions to provide a cleaner way + * to archieve both of these functions should be + * considered. + */ + if (unlikely(events_len == 0)) { + dsw_port_flush_out_buffers(dsw, source_port); + return 0; + } + + if (unlikely(events_len > source_port->enqueue_depth)) + events_len = source_port->enqueue_depth; + + if (!op_types_known) + for (i = 0; i < events_len; i++) { + switch (events[i].op) { + case RTE_EVENT_OP_RELEASE: + num_release++; + break; + case RTE_EVENT_OP_NEW: + num_new++; + /* Falls through. */ + default: + num_non_release++; + break; + } + } + + /* Technically, we could allow the non-new events up to the + * first new event in the array into the system, but for + * simplicity reasons, we deny the whole burst if the port is + * above the water mark. + */ + if (unlikely(num_new > 0 && rte_atomic32_read(&dsw->credits_on_loan) > + source_port->new_event_threshold)) + return 0; + + enough_credits = dsw_port_acquire_credits(dsw, source_port, + num_non_release); + if (unlikely(!enough_credits)) + return 0; + + source_port->pending_releases -= num_release; + + for (i = 0; i < events_len; i++) { + const struct rte_event *event = &events[i]; + + if (likely(num_release == 0 || + event->op != RTE_EVENT_OP_RELEASE)) + dsw_port_buffer_event(dsw, source_port, event); + } + + DSW_LOG_DP_PORT(DEBUG, source_port->id, "%d non-release events " + "accepted.\n", num_non_release); + + return num_non_release; +} + +uint16_t +dsw_event_enqueue_burst(void *port, const struct rte_event events[], + uint16_t events_len) +{ + return dsw_event_enqueue_burst_generic(port, events, events_len, false, + 0, 0, 0); +} + +uint16_t +dsw_event_enqueue_new_burst(void *port, const struct rte_event events[], + uint16_t events_len) +{ + return dsw_event_enqueue_burst_generic(port, events, events_len, true, + events_len, 0, events_len); +} + +uint16_t +dsw_event_enqueue_forward_burst(void *port, const struct rte_event events[], + uint16_t events_len) +{ + return dsw_event_enqueue_burst_generic(port, events, events_len, true, + 0, 0, events_len); +} + +uint16_t +dsw_event_dequeue(void *port, struct rte_event *events, uint64_t wait) +{ + return dsw_event_dequeue_burst(port, events, 1, wait); +} + +static uint16_t +dsw_port_dequeue_burst(struct dsw_port *port, struct rte_event *events, + uint16_t num) +{ + return rte_event_ring_dequeue_burst(port->in_ring, events, num, NULL); +} + +uint16_t +dsw_event_dequeue_burst(void *port, struct rte_event *events, uint16_t num, + uint64_t wait __rte_unused) +{ + struct dsw_port *source_port = port; + struct dsw_evdev *dsw = source_port->dsw; + uint16_t dequeued; + + source_port->pending_releases = 0; + + if (unlikely(num > source_port->dequeue_depth)) + num = source_port->dequeue_depth; + + dequeued = dsw_port_dequeue_burst(source_port, events, num); + + source_port->pending_releases = dequeued; + + if (dequeued > 0) { + DSW_LOG_DP_PORT(DEBUG, source_port->id, "Dequeued %d events.\n", + dequeued); + + dsw_port_return_credits(dsw, source_port, dequeued); + } + /* XXX: Assuming the port can't produce any more work, + * consider flushing the output buffer, on dequeued == + * 0. + */ + + return dequeued; +} diff --git a/drivers/event/dsw/meson.build b/drivers/event/dsw/meson.build index 275d051c37..bd2e4c809c 100644 --- a/drivers/event/dsw/meson.build +++ b/drivers/event/dsw/meson.build @@ -3,4 +3,4 @@ allow_experimental_apis = true deps += ['bus_vdev'] -sources = files('dsw_evdev.c') +sources = files('dsw_evdev.c', 'dsw_event.c')