Playing around with the mbuf structure, trying to reduce the use of the
second cache line in some common scenarios.
v2:
* Remove BUILD_BUG_ON in cnxk PMD.
Signed-off-by: Morten Brørup <m...@smartsharesystems.com>
---
drivers/net/cnxk/cn10k_ethdev.c | 2 ++
drivers/net/cnxk/cn9k_ethdev.c | 2 ++
lib/mbuf/rte_mbuf_core.h | 38 ++++++++++++++++-----------------
3 files changed, 23 insertions(+), 19 deletions(-)
diff --git a/drivers/net/cnxk/cn10k_ethdev.c b/drivers/net/cnxk/cn10k_ethdev.c
index 4658713591..9f6086efe6 100644
--- a/drivers/net/cnxk/cn10k_ethdev.c
+++ b/drivers/net/cnxk/cn10k_ethdev.c
@@ -72,8 +72,10 @@ nix_tx_offload_flags(struct rte_eth_dev *eth_dev)
offsetof(struct rte_mbuf, buf_addr) + 24);
RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, pkt_len) !=
offsetof(struct rte_mbuf, ol_flags) + 12);
+/*
RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, tx_offload) !=
offsetof(struct rte_mbuf, pool) + 2 * sizeof(void *));
+*/
if (conf & RTE_ETH_TX_OFFLOAD_VLAN_INSERT ||
conf & RTE_ETH_TX_OFFLOAD_QINQ_INSERT)
diff --git a/drivers/net/cnxk/cn9k_ethdev.c b/drivers/net/cnxk/cn9k_ethdev.c
index 3b702d9696..3e9161ca79 100644
--- a/drivers/net/cnxk/cn9k_ethdev.c
+++ b/drivers/net/cnxk/cn9k_ethdev.c
@@ -72,8 +72,10 @@ nix_tx_offload_flags(struct rte_eth_dev *eth_dev)
offsetof(struct rte_mbuf, buf_addr) + 24);
RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, pkt_len) !=
offsetof(struct rte_mbuf, ol_flags) + 12);
+/*
RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, tx_offload) !=
offsetof(struct rte_mbuf, pool) + 2 * sizeof(void *));
+*/
if (conf & RTE_ETH_TX_OFFLOAD_VLAN_INSERT ||
conf & RTE_ETH_TX_OFFLOAD_QINQ_INSERT)
diff --git a/lib/mbuf/rte_mbuf_core.h b/lib/mbuf/rte_mbuf_core.h
index a30e1e0eaf..c0c3b45024 100644
--- a/lib/mbuf/rte_mbuf_core.h
+++ b/lib/mbuf/rte_mbuf_core.h
@@ -594,25 +594,6 @@ struct rte_mbuf {
uint16_t buf_len; /**< Length of segment buffer. */
- struct rte_mempool *pool; /**< Pool from which mbuf was allocated. */
-
- /* second cache line - fields only used in slow path or on TX */
- RTE_MARKER cacheline1 __rte_cache_min_aligned;
-
-#if RTE_IOVA_AS_PA
- /**
- * Next segment of scattered packet. Must be NULL in the last
- * segment or in case of non-segmented packet.
- */
- struct rte_mbuf *next;
-#else
- /**
- * Reserved for dynamic fields
- * when the next pointer is in first cache line (i.e. RTE_IOVA_AS_PA is
0).
- */
- uint64_t dynfield2;
-#endif
-
/* fields to support TX offloads */
RTE_STD_C11
union {
@@ -651,6 +632,25 @@ struct rte_mbuf {
};
};
+ /* second cache line - fields only used in slow path or on TX */
+ RTE_MARKER cacheline1 __rte_cache_min_aligned;
+
+#if RTE_IOVA_AS_PA
+ /**
+ * Next segment of scattered packet. Must be NULL in the last
+ * segment or in case of non-segmented packet.
+ */
+ struct rte_mbuf *next;
+#else
+ /**
+ * Reserved for dynamic fields
+ * when the next pointer is in first cache line (i.e. RTE_IOVA_AS_PA is
0).
+ */
+ uint64_t dynfield2;
+#endif
+
+ struct rte_mempool *pool; /**< Pool from which mbuf was allocated. */
+
/** Shared data for external buffer attached to mbuf. See
* rte_pktmbuf_attach_extbuf().
*/
--
2.17.1
