[dpdk-dev] [PATCH 3/3] null: add xstats to provide the number of rx polls

[Paul Atkins]

When using the null driver and passing in packets via
the rx ring, it is useful to know that the driver has
polled the ring. Add a count of rx polls to the xstats
to provide this information.

Signed-off-by: Paul Atkins <patkins at brocade.com>
---
 drivers/net/null/rte_eth_null.c |   70 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/drivers/net/null/rte_eth_null.c b/drivers/net/null/rte_eth_null.c
index 176f477..3feab44 100644
--- a/drivers/net/null/rte_eth_null.c
+++ b/drivers/net/null/rte_eth_null.c
@@ -65,6 +65,15 @@ static const char *valid_arguments[] = {
 
 struct pmd_internals;
 
+struct eth_null_xstats {
+	rte_atomic64_t rx_polls;
+	rte_atomic64_t tx_polls;
+};
+
+struct eth_null_hw_stats {
+	uint64_t rx_polls;
+};
+
 struct null_queue {
 	struct pmd_internals *internals;
 
@@ -74,6 +83,7 @@ struct null_queue {
 	rte_atomic64_t rx_pkts;
 	rte_atomic64_t tx_pkts;
 	rte_atomic64_t err_pkts;
+	struct eth_null_xstats xstats;
 };
 
 struct pmd_internals {
@@ -109,6 +119,19 @@ static struct rte_eth_link pmd_link = {
 	.link_status = 0
 };
 
+/* store statistics names and its offset in stats structure */
+struct eth_null_xstats_name_off {
+	char name[RTE_ETH_XSTATS_NAME_SIZE];
+	unsigned offset;
+};
+
+static const struct eth_null_xstats_name_off eth_null_stats_strings[] = {
+	{"rx_polls", offsetof(struct eth_null_xstats, rx_polls)},
+};
+
+#define ETH_NULL_NB_XSTATS_PER_Q (sizeof(eth_null_stats_strings) /	\
+				  sizeof(eth_null_stats_strings[0]))
+
 static uint16_t
 eth_null_rx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
 {
@@ -175,6 +198,7 @@ eth_null_copy_rx_from_ring(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
 	i = rte_ring_mc_dequeue_burst(h->internals->rx_ring, (void **)bufs,
 				      nb_bufs);
 	rte_atomic64_add(&h->rx_pkts, 1);
+	rte_atomic64_add(&h->xstats.rx_polls, 1);
 
 	return i;
 }
@@ -231,6 +255,7 @@ eth_null_copy_tx_to_ring(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
 				   nb_bufs);
 
 	rte_atomic64_add(&h->tx_pkts, 1);
+	rte_atomic64_add(&h->tx_pkts, i);
 
 	return i;
 }
@@ -410,6 +435,49 @@ eth_stats_reset(struct rte_eth_dev *dev)
 	}
 }
 
+static int
+eth_xstats_get(struct rte_eth_dev *dev, struct rte_eth_xstats *xstats,
+	       unsigned n)
+{
+	struct pmd_internals *internal;
+	unsigned count = ETH_NULL_NB_XSTATS_PER_Q * dev->data->nb_rx_queues;
+	unsigned q, i = 0;
+	uint64_t val, *stats_ptr;
+
+	if (n < count)
+		return count;
+
+	internal = dev->data->dev_private;
+
+	/* Extended stats */
+	count = 0;
+	for (q = 0; q < ETH_NULL_NB_XSTATS_PER_Q; q++) {
+		for (i = 0; i < dev->data->nb_rx_queues; i++) {
+			stats_ptr = RTE_PTR_ADD(
+				&internal->rx_null_queues[q].xstats,
+				eth_null_stats_strings[i].offset +
+				q * sizeof(uint64_t));
+			val = *stats_ptr;
+			snprintf(xstats[count].name, sizeof(xstats[count].name),
+				 "rx_queue_%u_%s", q,
+				 eth_null_stats_strings[count].name);
+			xstats[count++].value = val;
+		}
+	}
+	return count;
+}
+
+static void
+eth_xstats_reset(struct rte_eth_dev *dev)
+{
+	struct pmd_internals *internal;
+	unsigned i;
+
+	internal = dev->data->dev_private;
+	for (i = 0; i < dev->data->nb_rx_queues; i++)
+		internal->rx_null_queues[i].xstats.rx_polls.cnt = 0;
+}
+
 static void
 eth_queue_release(void *q)
 {
@@ -523,6 +591,8 @@ static const struct eth_dev_ops ops = {
 	.link_update = eth_link_update,
 	.stats_get = eth_stats_get,
 	.stats_reset = eth_stats_reset,
+	.xstats_get = eth_xstats_get,
+	.xstats_reset = eth_xstats_reset,
 	.reta_update = eth_rss_reta_update,
 	.reta_query = eth_rss_reta_query,
 	.rss_hash_update = eth_rss_hash_update,
-- 
1.7.10.4