[dpdk-dev] [PATCH] event/sw: fix credit tracking in port dequeue

Harry van Haaren harry.van.haaren at intel.com
Mon May 29 17:16:55 CEST 2017


This patch targets the next-eventdev tree.

Single-link optimized ports previously did not correctly track
credits when dequeued, and re-enqueued as a FORWARD type. This
could "inflate" the number of credits in the system.

A unit test is added to reproduce and verify the issue. The
fixed implementation counts FORWARD packets and reduces the
number of credits the port has if it is of single-link type.

Fixes: 656af9180014 ("event/sw: add worker core functions")

Signed-off-by: Harry van Haaren <harry.van.haaren at intel.com>
---
 drivers/event/sw/sw_evdev_worker.c |  5 ++++
 test/test/test_eventdev_sw.c       | 58 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/drivers/event/sw/sw_evdev_worker.c b/drivers/event/sw/sw_evdev_worker.c
index 9cb6bef..b738506 100644
--- a/drivers/event/sw/sw_evdev_worker.c
+++ b/drivers/event/sw/sw_evdev_worker.c
@@ -87,6 +87,7 @@ sw_event_enqueue_burst(void *port, const struct rte_event ev[], uint16_t num)
 			return 0;
 	}
 
+	uint32_t forwards = 0;
 	for (i = 0; i < num; i++) {
 		int op = ev[i].op;
 		int outstanding = p->outstanding_releases > 0;
@@ -95,6 +96,7 @@ sw_event_enqueue_burst(void *port, const struct rte_event ev[], uint16_t num)
 		p->inflight_credits -= (op == RTE_EVENT_OP_NEW);
 		p->inflight_credits += (op == RTE_EVENT_OP_RELEASE) *
 					outstanding;
+		forwards += (op == RTE_EVENT_OP_FORWARD);
 
 		new_ops[i] = sw_qe_flag_map[op];
 		new_ops[i] &= ~(invalid_qid << QE_FLAG_VALID_SHIFT);
@@ -113,6 +115,9 @@ sw_event_enqueue_burst(void *port, const struct rte_event ev[], uint16_t num)
 		}
 	}
 
+	/* handle directed port forward credits */
+	p->inflight_credits -= forwards * p->is_directed;
+
 	/* returns number of events actually enqueued */
 	uint32_t enq = qe_ring_enqueue_burst_with_ops(p->rx_worker_ring, ev, i,
 					     new_ops);
diff --git a/test/test/test_eventdev_sw.c b/test/test/test_eventdev_sw.c
index b187d02..aaa9729 100644
--- a/test/test/test_eventdev_sw.c
+++ b/test/test/test_eventdev_sw.c
@@ -548,6 +548,57 @@ test_single_directed_packet(struct test *t)
 	return 0;
 }
 
+static int
+test_directed_forward_credits(struct test *t)
+{
+	uint32_t i;
+	int32_t err;
+
+	if (init(t, 1, 1) < 0 ||
+			create_ports(t, 1) < 0 ||
+			create_directed_qids(t, 1, t->port) < 0)
+		return -1;
+
+	if (rte_event_dev_start(evdev) < 0) {
+		printf("%d: Error with start call\n", __LINE__);
+		return -1;
+	}
+
+	struct rte_event ev = {
+			.op = RTE_EVENT_OP_NEW,
+			.queue_id = 0,
+	};
+
+	for (i = 0; i < 1000; i++) {
+		err = rte_event_enqueue_burst(evdev, 0, &ev, 1);
+		if (err < 0) {
+			printf("%d: error failed to enqueue\n", __LINE__);
+			return -1;
+		}
+		rte_event_schedule(evdev);
+		struct test_event_dev_stats stats;
+		err = test_event_dev_stats_get(evdev, &stats);
+		if (err) {
+			printf("%d: error failed to get stats\n", __LINE__);
+			return -1;
+		}
+
+		uint32_t deq_pkts;
+		deq_pkts = rte_event_dequeue_burst(evdev, 0, &ev, 1, 0);
+		if (deq_pkts != 1) {
+			printf("%d: error failed to deq\n", __LINE__);
+			return -1;
+		}
+
+		/* re-write event to be a forward, and continue looping it */
+		ev.op = RTE_EVENT_OP_FORWARD;
+	}
+
+	//rte_event_dev_dump(0, stdout);
+	cleanup(t);
+	return 0;
+}
+
 
 static int
 test_priority_directed(struct test *t)
@@ -3025,13 +3076,18 @@ test_sw_eventdev(void)
 		}
 	}
 	t->mbuf_pool = eventdev_func_mempool;
-
 	printf("*** Running Single Directed Packet test...\n");
 	ret = test_single_directed_packet(t);
 	if (ret != 0) {
 		printf("ERROR - Single Directed Packet test FAILED.\n");
 		return ret;
 	}
+	printf("*** Running Directed Forward Credit test...\n");
+	ret = test_directed_forward_credits(t);
+	if (ret != 0) {
+		printf("ERROR - Directed Forward Credit test FAILED.\n");
+		return ret;
+	}
 	printf("*** Running Single Load Balanced Packet test...\n");
 	ret = single_packet(t);
 	if (ret != 0) {
-- 
2.7.4



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