From 4deeb214ac0b33c61ebc1722ef31510f8e9492e6 Mon Sep 17 00:00:00 2001 From: Gage Eads Date: Mon, 12 Mar 2018 09:55:22 -0500 Subject: [PATCH] event/sw: perform partial burst enqueues Previously, the sw PMD would enqueue either all or no events, depending on if enough inflight credits were available for the new events in the burst. If a port is enqueueing a large burst (i.e. a multiple of the credit update quanta), this can result in suboptimal performance, and requires an understanding of the sw PMD implementation (in particular, its credit scheme) to tune an application's burst size. This affects software that enqueues large bursts of new events, such as the ethernet event adapter which uses a 128-deep event buffer, when the input packet rate is sufficiently high. This change makes the sw PMD enqueue as many events as it has credits, if there are any new events in the burst. Signed-off-by: Gage Eads Acked-by: Harry van Haaren --- drivers/event/sw/sw_evdev_worker.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/event/sw/sw_evdev_worker.c b/drivers/event/sw/sw_evdev_worker.c index 67151f7768..063b919c7e 100644 --- a/drivers/event/sw/sw_evdev_worker.c +++ b/drivers/event/sw/sw_evdev_worker.c @@ -77,8 +77,10 @@ sw_event_enqueue_burst(void *port, const struct rte_event ev[], uint16_t num) rte_atomic32_add(&sw->inflights, credit_update_quanta); p->inflight_credits += (credit_update_quanta); - if (p->inflight_credits < new) - return 0; + /* If there are fewer inflight credits than new events, limit + * the number of enqueued events. + */ + num = (p->inflight_credits < new) ? p->inflight_credits : new; } for (i = 0; i < num; i++) {