[dpdk-dev] [RFC v2 2/2] doc: announce queue stats moving to xstats

[Ferruh Yigit <ferruh.yigit@intel.com>]

Queue stats will be removed from basic stats to xstats.

It will be PMDs responsibility to fill queue stats based on number of
queues they have.

Until all PMDs implement the xstats, a temporary
'RTE_ETH_DEV_AUTOFILL_QUEUE_XSTATS' device flag created. PMDs switched
to the xstats should clear this flag to bypass the ethdev layer autofill
for queue stats.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
 config/rte_config.h                  | 2 +-
 doc/guides/rel_notes/deprecation.rst | 7 +++++++
 lib/librte_ethdev/rte_ethdev.h       | 3 +++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/config/rte_config.h b/config/rte_config.h
index 03d90d78bc..9ef3b75940 100644
--- a/config/rte_config.h
+++ b/config/rte_config.h
@@ -55,7 +55,7 @@
 
 /* ether defines */
 #define RTE_MAX_QUEUES_PER_PORT 1024
-#define RTE_ETHDEV_QUEUE_STAT_CNTRS 16
+#define RTE_ETHDEV_QUEUE_STAT_CNTRS 16 /* max 256 */
 #define RTE_ETHDEV_RXTX_CALLBACKS 1
 
 /* cryptodev defines */
diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index 584e720879..9143cfc529 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -164,6 +164,13 @@ Deprecation Notices
   following the IPv6 header, as proposed in RFC
   https://mails.dpdk.org/archives/dev/2020-August/177257.html.
 
+* ethdev: Queue specific stats fields will be removed from ``struct rte_eth_stats``.
+  Mentioned fields are: ``q_ipackets``, ``q_opackets``, ``q_ibytes``, ``q_obytes``,
+  ``q_errors``.
+  Instead queue stats will be received via xstats API. Current method support
+  will be limited to maximum 256 queues.
+  Also compile time flag ``RTE_ETHDEV_QUEUE_STAT_CNTRS`` will be removed.
+
 * security: The API ``rte_security_session_create`` takes only single mempool
   for session and session private data. So the application need to create
   mempool for twice the number of sessions needed and will also lead to
diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
index bb7a2b4289..a2e811ca48 100644
--- a/lib/librte_ethdev/rte_ethdev.h
+++ b/lib/librte_ethdev/rte_ethdev.h
@@ -253,6 +253,7 @@ struct rte_eth_stats {
 	uint64_t ierrors;   /**< Total number of erroneous received packets. */
 	uint64_t oerrors;   /**< Total number of failed transmitted packets. */
 	uint64_t rx_nombuf; /**< Total number of RX mbuf allocation failures. */
+	/* Queue stats are limited to max 256 queues */
 	uint64_t q_ipackets[RTE_ETHDEV_QUEUE_STAT_CNTRS];
 	/**< Total number of queue RX packets. */
 	uint64_t q_opackets[RTE_ETHDEV_QUEUE_STAT_CNTRS];
@@ -2704,6 +2705,7 @@ int rte_eth_xstats_reset(uint16_t port_id);
  *   The per-queue packet statistics functionality number that the transmit
  *   queue is to be assigned.
  *   The value must be in the range [0, RTE_ETHDEV_QUEUE_STAT_CNTRS - 1].
+ *   Max RTE_ETHDEV_QUEUE_STAT_CNTRS being 256.
  * @return
  *   Zero if successful. Non-zero otherwise.
  */
@@ -2724,6 +2726,7 @@ int rte_eth_dev_set_tx_queue_stats_mapping(uint16_t port_id,
  *   The per-queue packet statistics functionality number that the receive
  *   queue is to be assigned.
  *   The value must be in the range [0, RTE_ETHDEV_QUEUE_STAT_CNTRS - 1].
+ *   Max RTE_ETHDEV_QUEUE_STAT_CNTRS being 256.
  * @return
  *   Zero if successful. Non-zero otherwise.
  */
-- 
2.26.2