[dpdk-dev] [PATCH v3 01/10] rte: change xstats to use integer ids

[Remy Horton]

The current extended ethernet statistics fetching involve doing several
string operations, which causes performance issues if there are lots of
statistics and/or network interfaces. This patch changes the API for
xstats to use integer identifiers instead of strings.

Signed-off-by: Remy Horton <remy.horton at intel.com>
---
 lib/librte_ether/rte_ethdev.c          | 95 +++++++++++++++++++++++++++++++---
 lib/librte_ether/rte_ethdev.h          | 44 ++++++++++++++++
 lib/librte_ether/rte_ether_version.map |  7 +++
 3 files changed, 138 insertions(+), 8 deletions(-)

diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index e148028..86fb0bc 100644
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -1502,6 +1502,87 @@ rte_eth_stats_reset(uint8_t port_id)
 	dev->data->rx_mbuf_alloc_failed = 0;
 }
 
+int
+rte_eth_xstats_count(uint8_t port_id)
+{
+	struct rte_eth_dev *dev;
+	int count;
+
+	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
+	dev = &rte_eth_devices[port_id];
+	if (dev->dev_ops->xstats_names != NULL) {
+		count = (*dev->dev_ops->xstats_names)(dev, NULL, 0);
+		if (count < 0)
+			return count;
+	} else
+		count = 0;
+	count += RTE_NB_STATS;
+	count += dev->data->nb_rx_queues * RTE_NB_RXQ_STATS;
+	count += dev->data->nb_tx_queues * RTE_NB_TXQ_STATS;
+	return count;
+}
+
+int
+rte_eth_xstats_names(uint8_t port_id, struct rte_eth_xstats_name *ptr_names,
+	unsigned limit)
+{
+	struct rte_eth_dev *dev;
+	int cnt_used_entries;
+	int cnt_expected_entries;
+	uint32_t idx, id_queue;
+
+	if (ptr_names == NULL)
+		return -EINVAL;
+	cnt_expected_entries = rte_eth_xstats_count(port_id);
+	if (cnt_expected_entries < 0)
+		return cnt_expected_entries;
+	if ((int)limit < cnt_expected_entries)
+		return -ERANGE;
+
+	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
+	dev = &rte_eth_devices[port_id];
+	if (dev->dev_ops->xstats_names != NULL) {
+		cnt_used_entries = (*dev->dev_ops->xstats_names)(
+			dev, ptr_names, limit);
+		if (cnt_used_entries < 0)
+			return cnt_used_entries;
+	} else
+		/* Driver itself does not support extended stats, but
+		 * still have basic stats.
+		 */
+		cnt_used_entries = 0;
+
+	for (idx = 0; idx < RTE_NB_STATS; idx++) {
+		ptr_names[cnt_used_entries].id = cnt_used_entries;
+		snprintf(ptr_names[cnt_used_entries].name,
+			sizeof(ptr_names[0].name),
+			"%s", rte_stats_strings[idx].name);
+		cnt_used_entries++;
+	}
+	for (id_queue = 0; id_queue < dev->data->nb_rx_queues; id_queue++) {
+		for (idx = 0; idx < RTE_NB_RXQ_STATS; idx++) {
+			ptr_names[cnt_used_entries].id = cnt_used_entries;
+			snprintf(ptr_names[cnt_used_entries].name,
+				sizeof(ptr_names[0].name),
+				"rx_q%u%s",
+				id_queue, rte_rxq_stats_strings[idx].name);
+			cnt_used_entries++;
+		}
+
+	}
+	for (id_queue = 0; id_queue < dev->data->nb_tx_queues; id_queue++) {
+		for (idx = 0; idx < RTE_NB_TXQ_STATS; idx++) {
+			ptr_names[cnt_used_entries].id = cnt_used_entries;
+			snprintf(ptr_names[cnt_used_entries].name,
+				sizeof(ptr_names[0].name),
+				"tx_q%u%s",
+				id_queue, rte_txq_stats_strings[idx].name);
+			cnt_used_entries++;
+		}
+	}
+	return cnt_used_entries;
+}
+
 /* retrieve ethdev extended statistics */
 int
 rte_eth_xstats_get(uint8_t port_id, struct rte_eth_xstats *xstats,
@@ -1546,8 +1627,8 @@ rte_eth_xstats_get(uint8_t port_id, struct rte_eth_xstats *xstats,
 		stats_ptr = RTE_PTR_ADD(&eth_stats,
 					rte_stats_strings[i].offset);
 		val = *stats_ptr;
-		snprintf(xstats[count].name, sizeof(xstats[count].name),
-			"%s", rte_stats_strings[i].name);
+		xstats[count].name[0] = '\0';
+		xstats[count].id = count + xcount;
 		xstats[count++].value = val;
 	}
 
@@ -1558,9 +1639,8 @@ rte_eth_xstats_get(uint8_t port_id, struct rte_eth_xstats *xstats,
 					rte_rxq_stats_strings[i].offset +
 					q * sizeof(uint64_t));
 			val = *stats_ptr;
-			snprintf(xstats[count].name, sizeof(xstats[count].name),
-				"rx_q%u_%s", q,
-				rte_rxq_stats_strings[i].name);
+			xstats[count].name[0] = '\0';
+			xstats[count].id = count + xcount;
 			xstats[count++].value = val;
 		}
 	}
@@ -1572,9 +1652,8 @@ rte_eth_xstats_get(uint8_t port_id, struct rte_eth_xstats *xstats,
 					rte_txq_stats_strings[i].offset +
 					q * sizeof(uint64_t));
 			val = *stats_ptr;
-			snprintf(xstats[count].name, sizeof(xstats[count].name),
-				"tx_q%u_%s", q,
-				rte_txq_stats_strings[i].name);
+			xstats[count].name[0] = '\0';
+			xstats[count].id = count + xcount;
 			xstats[count++].value = val;
 		}
 	}
diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
index 2757510..d663d60 100644
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -915,10 +915,23 @@ struct rte_eth_txq_info {
  * structure.
  */
 struct rte_eth_xstats {
+	/* FIXME: Remove name[] once remaining drivers converted */
 	char name[RTE_ETH_XSTATS_NAME_SIZE];
+	uint64_t id;
 	uint64_t value;
 };
 
+/**
+ * A name-key lookup element for extended statistics.
+ *
+ * This structure is used to map between names and ID numbers
+ * for extended ethernet statistics.
+ */
+struct rte_eth_xstats_name {
+	char name[RTE_ETH_XSTATS_NAME_SIZE];
+	uint64_t id;
+};
+
 #define ETH_DCB_NUM_TCS    8
 #define ETH_MAX_VMDQ_POOL  64
 
@@ -1054,6 +1067,10 @@ typedef int (*eth_xstats_get_t)(struct rte_eth_dev *dev,
 typedef void (*eth_xstats_reset_t)(struct rte_eth_dev *dev);
 /**< @internal Reset extended stats of an Ethernet device. */
 
+typedef int (*eth_xstats_names_t)(struct rte_eth_dev *dev,
+	struct rte_eth_xstats_name *ptr_names, unsigned limit);
+/**< @internal Get names of extended stats of an Ethernet device. */
+
 typedef int (*eth_queue_stats_mapping_set_t)(struct rte_eth_dev *dev,
 					     uint16_t queue_id,
 					     uint8_t stat_idx,
@@ -1401,6 +1418,8 @@ struct eth_dev_ops {
 	eth_stats_reset_t          stats_reset;   /**< Reset generic device statistics. */
 	eth_xstats_get_t           xstats_get;    /**< Get extended device statistics. */
 	eth_xstats_reset_t         xstats_reset;  /**< Reset extended device statistics. */
+	eth_xstats_names_t         xstats_names;
+	/**< Get names of extended statistics. */
 	eth_queue_stats_mapping_set_t queue_stats_mapping_set;
 	/**< Configure per queue stat counter mapping. */
 	eth_dev_infos_get_t        dev_infos_get; /**< Get device info. */
@@ -2253,6 +2272,31 @@ int rte_eth_stats_get(uint8_t port_id, struct rte_eth_stats *stats);
 void rte_eth_stats_reset(uint8_t port_id);
 
 /**
+ * Retrieve names of extended statistics of an Ethernet device.
+ *
+ * @param port_id
+ *   The port identifier of the Ethernet device.
+ * @param ptr_names
+ *  Block of memory to insert names into. Must be at least limit in size.
+ * @param limit
+ *  Capacity of ptr_strings (number of names).
+ * @return
+ *  If successful, number of statistics; negative on error.
+ */
+int rte_eth_xstats_names(uint8_t port_id, struct rte_eth_xstats_name *ptr_names,
+	unsigned limit);
+
+/**
+ * Retrieve number of extended statistics of an Ethernet device.
+ *
+ * @param port_id
+ *   The port identifier of the Ethernet device.
+ * @return
+ *  If successful, number of statistics; negative on error.
+ */
+int rte_eth_xstats_count(uint8_t port_id);
+
+/**
  * Retrieve extended statistics of an Ethernet device.
  *
  * @param port_id
diff --git a/lib/librte_ether/rte_ether_version.map b/lib/librte_ether/rte_ether_version.map
index 214ecc7..bb339e1 100644
--- a/lib/librte_ether/rte_ether_version.map
+++ b/lib/librte_ether/rte_ether_version.map
@@ -132,3 +132,10 @@ DPDK_16.04 {
 	rte_eth_tx_buffer_set_err_callback;
 
 } DPDK_2.2;
+
+DPDK_16.07 {
+	global:
+
+	rte_eth_xstats_names;
+	rte_eth_xstats_count;
+} DPDK_16.04;
-- 
2.5.5