RE: [EXTERNAL] [PATCH v3 2/2] graph: add alignment to the member of rte_node

[Jerin Jacob <jerinj@marvell.com>]

> -----Original Message-----
> From: Huichao Cai <chcchc88@163.com>
> Sent: Wednesday, November 13, 2024 1:06 PM
> To: Jerin Jacob <jerinj@marvell.com>; Kiran Kumar Kokkilagadda
> <kirankumark@marvell.com>; Nithin Kumar Dabilpuram
> <ndabilpuram@marvell.com>; yanzhirun_163@163.com
> Cc: dev@dpdk.org
> Subject: [EXTERNAL] [PATCH v3 2/2] graph: add alignment to the member of
> rte_node
> 
> 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. Due to the modification of the alignment of some members of the
> "rte_node"
> 
> 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.
> 
> Due to the modification of the alignment of some members of the "rte_node"
> structure, update file release_24_11.rst.
> 
> Signed-off-by: Huichao Cai <chcchc88@163.com>
> ---
>  doc/guides/rel_notes/release_24_11.rst | 3 +++
>  lib/graph/rte_graph_worker_common.h    | 5 ++++-
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/doc/guides/rel_notes/release_24_11.rst
> b/doc/guides/rel_notes/release_24_11.rst
> index 592116b979..6903b1d0f0 100644
> --- a/doc/guides/rel_notes/release_24_11.rst
> +++ b/doc/guides/rel_notes/release_24_11.rst
> @@ -425,6 +425,9 @@ ABI Changes
> 
>  * graph: added ``graph`` field to the ``dispatch`` structure in the ``rte_node``
> structure.
> 
> +* 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 4c2432b47f..9e99278a0a 100644
> --- a/lib/graph/rte_graph_worker_common.h
> +++ b/lib/graph/rte_graph_worker_common.h
> @@ -104,6 +104,7 @@ struct __rte_cache_aligned rte_node {
>  	/** Original process function when pcap is enabled. */
>  	rte_node_process_t original_process;
> 
> +	alignas(RTE_CACHE_LINE_MIN_SIZE)
>  	union {
>  		/* Fast schedule area for mcore dispatch model */
>  		struct {
> @@ -113,8 +114,10 @@ struct __rte_cache_aligned rte_node {
>  			struct rte_graph *graph;  /**< Graph corresponding to
> lcore_id. */
>  		} dispatch;
>  	};
> -	rte_graph_off_t xstat_off; /**< Offset to xstat counters. */
> +
>  	/* Fast path area  */

Make it as two separate comment, Fast path area cache line 1 and Fastpath area cache line 2.

> +	alignas(RTE_CACHE_LINE_MIN_SIZE)
> +	rte_graph_off_t xstat_off; /**< Offset to xstat counters. */
>  	__extension__ struct __rte_cache_aligned {  #define RTE_NODE_CTX_SZ
> 16
>  		union {
> --
> 2.27.0