[PATCH v5 1/1] graph: improve node layout

[Huichao Cai]

The members "dispatch" and "xstat_off" of the structure "rte_node"
can be min cache aligned to make room for future expansion and to
make sure have better performance. Add corresponding comments.

Signed-off-by: Huichao Cai <chcchc88 at 163.com>
---
 doc/guides/rel_notes/release_24_11.rst |  2 ++
 lib/graph/rte_graph_worker_common.h    | 10 +++++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/doc/guides/rel_notes/release_24_11.rst b/doc/guides/rel_notes/release_24_11.rst
index 5063badf39..32800e8cb0 100644
--- a/doc/guides/rel_notes/release_24_11.rst
+++ b/doc/guides/rel_notes/release_24_11.rst
@@ -491,6 +491,8 @@ ABI Changes
   added new structure ``rte_node_xstats`` to ``rte_node_register`` and
   added ``xstat_off`` to ``rte_node``.
 
+* graph: The members ``dispatch`` and ``xstat_off`` of the structure ``rte_node`` have been
+  marked as RTE_CACHE_LINE_MIN_SIZE bytes aligned.
 
 Known Issues
 ------------
diff --git a/lib/graph/rte_graph_worker_common.h b/lib/graph/rte_graph_worker_common.h
index a518af2b2a..d3ec88519d 100644
--- a/lib/graph/rte_graph_worker_common.h
+++ b/lib/graph/rte_graph_worker_common.h
@@ -104,16 +104,20 @@ struct __rte_cache_aligned rte_node {
 	/** Original process function when pcap is enabled. */
 	rte_node_process_t original_process;
 
+	/** Fast schedule area for mcore dispatch model. */
 	union {
-		/* Fast schedule area for mcore dispatch model */
-		struct {
+		alignas(RTE_CACHE_LINE_MIN_SIZE) struct {
 			unsigned int lcore_id;  /**< Node running lcore. */
 			uint64_t total_sched_objs; /**< Number of objects scheduled. */
 			uint64_t total_sched_fail; /**< Number of scheduled failure. */
 		} dispatch;
 	};
+
+	/** Fast path area cache line 1. */
+	alignas(RTE_CACHE_LINE_MIN_SIZE)
 	rte_graph_off_t xstat_off; /**< Offset to xstat counters. */
-	/* Fast path area  */
+
+	/** Fast path area cache line 2. */
 	__extension__ struct __rte_cache_aligned {
 #define RTE_NODE_CTX_SZ 16
 		union {
-- 
2.27.0