[dpdk-dev] [PATCH v3 3/3] event/sw: add xstat for work done in last iteration

[Harry van Haaren <harry.van.haaren@intel.com>]

Today it is difficult to know what Eventdev ports recieved work
from the scheduling core. Sometimes it is useful to know where
work has been scheduled.

This patch implements an xstat for the SW PMD, which provides a
bitmask of ports that were scheduled to. If the SW PMD instance
has more than 64 ports, always report that a port got an event.

Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>

---

Note most of the changes here are unit-test changes to add
a statistic to the PMD. The actual "useful code" is a mere
handful of lines in a lot of noise.. could split into 2 patches?
---
 drivers/event/sw/sw_evdev.h           |  1 +
 drivers/event/sw/sw_evdev_scheduler.c | 12 ++++++++++++
 drivers/event/sw/sw_evdev_selftest.c  | 27 ++++++++++++++-------------
 drivers/event/sw/sw_evdev_xstats.c    |  6 +++++-
 4 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/drivers/event/sw/sw_evdev.h b/drivers/event/sw/sw_evdev.h
index 5ab6465c83..5dfa4508b3 100644
--- a/drivers/event/sw/sw_evdev.h
+++ b/drivers/event/sw/sw_evdev.h
@@ -259,6 +259,7 @@ struct sw_evdev {
 	uint64_t sched_no_iq_enqueues;
 	uint64_t sched_no_cq_enqueues;
 	uint64_t sched_cq_qid_called;
+	uint64_t sched_last_iter_bitmask;
 
 	uint8_t started;
 	uint32_t credit_update_quanta;
diff --git a/drivers/event/sw/sw_evdev_scheduler.c b/drivers/event/sw/sw_evdev_scheduler.c
index c78f687446..3ee1188be0 100644
--- a/drivers/event/sw/sw_evdev_scheduler.c
+++ b/drivers/event/sw/sw_evdev_scheduler.c
@@ -566,6 +566,8 @@ sw_event_schedule(struct rte_eventdev *dev)
 	rte_service_component_attr_set(sw->service_id,
 			RTE_SERVICE_ATTR_USEFUL_WORK_LAST_ITER, work_done);
 
+	uint64_t cqs_scheds_last_iter = 0;
+
 	/* push all the internal buffered QEs in port->cq_ring to the
 	 * worker cores: aka, do the ring transfers batched.
 	 */
@@ -585,6 +587,7 @@ sw_event_schedule(struct rte_eventdev *dev)
 					&sw->cq_ring_space[i]);
 			port->cq_buf_count = 0;
 			no_enq = 0;
+			cqs_scheds_last_iter |= (1ULL << i);
 		} else {
 			sw->cq_ring_space[i] =
 					rte_event_ring_free_count(worker) -
@@ -604,4 +607,13 @@ sw_event_schedule(struct rte_eventdev *dev)
 			sw->sched_min_burst = sw->sched_min_burst_size;
 	}
 
+	/* Provide stats on what eventdev ports were scheduled to this
+	 * iteration. If more than 64 ports are active, always report that
+	 * all Eventdev ports have been scheduled events.
+	 */
+	if (likely(sw->port_count < 64)) {
+		sw->sched_last_iter_bitmask = cqs_scheds_last_iter;
+	} else {
+		sw->sched_last_iter_bitmask = UINT64_MAX;
+	}
 }
diff --git a/drivers/event/sw/sw_evdev_selftest.c b/drivers/event/sw/sw_evdev_selftest.c
index e4bfb3a0f1..7dd35cb22e 100644
--- a/drivers/event/sw/sw_evdev_selftest.c
+++ b/drivers/event/sw/sw_evdev_selftest.c
@@ -873,15 +873,15 @@ xstats_tests(struct test *t)
 	int ret = rte_event_dev_xstats_names_get(evdev,
 					RTE_EVENT_DEV_XSTATS_DEVICE,
 					0, xstats_names, ids, XSTATS_MAX);
-	if (ret != 6) {
-		printf("%d: expected 6 stats, got return %d\n", __LINE__, ret);
+	if (ret != 7) {
+		printf("%d: expected 7 stats, got return %d\n", __LINE__, ret);
 		return -1;
 	}
 	ret = rte_event_dev_xstats_get(evdev,
 					RTE_EVENT_DEV_XSTATS_DEVICE,
 					0, ids, values, ret);
-	if (ret != 6) {
-		printf("%d: expected 6 stats, got return %d\n", __LINE__, ret);
+	if (ret != 7) {
+		printf("%d: expected 7 stats, got return %d\n", __LINE__, ret);
 		return -1;
 	}
 
@@ -959,7 +959,7 @@ xstats_tests(struct test *t)
 	ret = rte_event_dev_xstats_get(evdev,
 					RTE_EVENT_DEV_XSTATS_DEVICE,
 					0, ids, values, num_stats);
-	static const uint64_t expected[] = {3, 3, 0, 1, 0, 0};
+	static const uint64_t expected[] = {3, 3, 0, 1, 0, 0, 4};
 	for (i = 0; (signed int)i < ret; i++) {
 		if (expected[i] != values[i]) {
 			printf(
@@ -975,7 +975,7 @@ xstats_tests(struct test *t)
 					0, NULL, 0);
 
 	/* ensure reset statistics are zero-ed */
-	static const uint64_t expected_zero[] = {0, 0, 0, 0, 0, 0};
+	static const uint64_t expected_zero[] = {0, 0, 0, 0, 0, 0, 0};
 	ret = rte_event_dev_xstats_get(evdev,
 					RTE_EVENT_DEV_XSTATS_DEVICE,
 					0, ids, values, num_stats);
@@ -1460,7 +1460,7 @@ xstats_id_reset_tests(struct test *t)
 	for (i = 0; i < XSTATS_MAX; i++)
 		ids[i] = i;
 
-#define NUM_DEV_STATS 6
+#define NUM_DEV_STATS 7
 	/* Device names / values */
 	int num_stats = rte_event_dev_xstats_names_get(evdev,
 					RTE_EVENT_DEV_XSTATS_DEVICE,
@@ -1504,8 +1504,9 @@ xstats_id_reset_tests(struct test *t)
 	static const char * const dev_names[] = {
 		"dev_rx", "dev_tx", "dev_drop", "dev_sched_calls",
 		"dev_sched_no_iq_enq", "dev_sched_no_cq_enq",
+		"dev_sched_last_iter_bitmask",
 	};
-	uint64_t dev_expected[] = {NPKTS, NPKTS, 0, 1, 0, 0};
+	uint64_t dev_expected[] = {NPKTS, NPKTS, 0, 1, 0, 0, 4};
 	for (i = 0; (int)i < ret; i++) {
 		unsigned int id;
 		uint64_t val = rte_event_dev_xstats_by_name_get(evdev,
@@ -1518,8 +1519,8 @@ xstats_id_reset_tests(struct test *t)
 		}
 		if (val != dev_expected[i]) {
 			printf("%d: %s value incorrect, expected %"
-				PRIu64" got %d\n", __LINE__, dev_names[i],
-				dev_expected[i], id);
+				PRIu64" got %ld\n", __LINE__, dev_names[i],
+				dev_expected[i], val);
 			goto fail;
 		}
 		/* reset to zero */
@@ -1542,11 +1543,11 @@ xstats_id_reset_tests(struct test *t)
 		}
 	};
 
-/* 48 is stat offset from start of the devices whole xstats.
+/* 49 is stat offset from start of the devices whole xstats.
  * This WILL break every time we add a statistic to a port
  * or the device, but there is no other way to test
  */
-#define PORT_OFF 48
+#define PORT_OFF 49
 /* num stats for the tested port. CQ size adds more stats to a port */
 #define NUM_PORT_STATS 21
 /* the port to test. */
@@ -1670,7 +1671,7 @@ xstats_id_reset_tests(struct test *t)
 /* queue offset from start of the devices whole xstats.
  * This will break every time we add a statistic to a device/port/queue
  */
-#define QUEUE_OFF 90
+#define QUEUE_OFF 91
 	const uint32_t queue = 0;
 	num_stats = rte_event_dev_xstats_names_get(evdev,
 					RTE_EVENT_DEV_XSTATS_QUEUE, queue,
diff --git a/drivers/event/sw/sw_evdev_xstats.c b/drivers/event/sw/sw_evdev_xstats.c
index 02f7874180..1b0ad68414 100644
--- a/drivers/event/sw/sw_evdev_xstats.c
+++ b/drivers/event/sw/sw_evdev_xstats.c
@@ -17,6 +17,7 @@ enum xstats_type {
 	/* device instance specific */
 	no_iq_enq,
 	no_cq_enq,
+	sched_last_iter_bitmask,
 	/* port_specific */
 	rx_used,
 	rx_free,
@@ -57,6 +58,8 @@ get_dev_stat(const struct sw_evdev *sw, uint16_t obj_idx __rte_unused,
 	case calls: return sw->sched_called;
 	case no_iq_enq: return sw->sched_no_iq_enqueues;
 	case no_cq_enq: return sw->sched_no_cq_enqueues;
+	case sched_last_iter_bitmask: return sw->sched_last_iter_bitmask;
+
 	default: return -1;
 	}
 }
@@ -177,9 +180,10 @@ sw_xstats_init(struct sw_evdev *sw)
 	 */
 	static const char * const dev_stats[] = { "rx", "tx", "drop",
 			"sched_calls", "sched_no_iq_enq", "sched_no_cq_enq",
+			"sched_last_iter_bitmask",
 	};
 	static const enum xstats_type dev_types[] = { rx, tx, dropped,
-			calls, no_iq_enq, no_cq_enq,
+			calls, no_iq_enq, no_cq_enq, sched_last_iter_bitmask,
 	};
 	/* all device stats are allowed to be reset */
 
-- 
2.25.1