[dpdk-dev] [PATCH v2 04/15] node: switch IPv4 metadata to dynamic mbuf field

[Nithin Dabilpuram]

On Mon, Oct 26, 2020 at 11:20:02PM +0100, Thomas Monjalon wrote:
> The node_mbuf_priv1 was stored in the deprecated mbuf field udata64.
> It is moved to a dynamic field in order to allow removal of udata64.
> 
> Signed-off-by: Thomas Monjalon <thomas at monjalon.net>
> ---
>  lib/librte_node/ip4_lookup.c   |  7 +++++++
>  lib/librte_node/ip4_rewrite.c  | 10 ++++++++++
>  lib/librte_node/node_private.h | 12 ++++++++++--
>  3 files changed, 27 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/librte_node/ip4_lookup.c b/lib/librte_node/ip4_lookup.c
> index 8835aab9dd..c2f6d653f9 100644
> --- a/lib/librte_node/ip4_lookup.c
> +++ b/lib/librte_node/ip4_lookup.c
> @@ -21,6 +21,8 @@
>  
>  #include "node_private.h"
>  
> +int node_mbuf_priv1_dynfield_offset;
> +

This change doesn't work in secondary as it is process local memory.

>  #define IPV4_L3FWD_LPM_MAX_RULES 1024
>  #define IPV4_L3FWD_LPM_NUMBER_TBL8S (1 << 8)
>  
> @@ -178,6 +180,11 @@ ip4_lookup_node_init(const struct rte_graph *graph, struct rte_node *node)
>  	RTE_SET_USED(node);
>  
>  	if (!init_once) {
> +		node_mbuf_priv1_dynfield_offset = rte_mbuf_dynfield_register(
> +				&node_mbuf_priv1_dynfield_desc);
> +		if (node_mbuf_priv1_dynfield_offset < 0)
> +			return -rte_errno;
> +
>  		/* Setup LPM tables for all sockets */
>  		RTE_LCORE_FOREACH(lcore_id)
>  		{
> diff --git a/lib/librte_node/ip4_rewrite.c b/lib/librte_node/ip4_rewrite.c
> index bb7f671b5c..1c4e51968c 100644
> --- a/lib/librte_node/ip4_rewrite.c
> +++ b/lib/librte_node/ip4_rewrite.c
> @@ -248,9 +248,19 @@ ip4_rewrite_node_process(struct rte_graph *graph, struct rte_node *node,
>  static int
>  ip4_rewrite_node_init(const struct rte_graph *graph, struct rte_node *node)
>  {
> +	static bool init_once;
>  
>  	RTE_SET_USED(graph);
>  	RTE_SET_USED(node);
> +
> +	if (!init_once) {
> +		node_mbuf_priv1_dynfield_offset = rte_mbuf_dynfield_register(
> +				&node_mbuf_priv1_dynfield_desc);
> +		if (node_mbuf_priv1_dynfield_offset < 0)
> +			return -rte_errno;
> +		init_once = true;
> +	}
> +
>  	node_dbg("ip4_rewrite", "Initialized ip4_rewrite node initialized");
>  
>  	return 0;
> diff --git a/lib/librte_node/node_private.h b/lib/librte_node/node_private.h
> index ab7941c12b..359b40faed 100644
> --- a/lib/librte_node/node_private.h
> +++ b/lib/librte_node/node_private.h
> @@ -8,6 +8,7 @@
>  #include <rte_common.h>
>  #include <rte_log.h>
>  #include <rte_mbuf.h>
> +#include <rte_mbuf_dyn.h>
>  
>  extern int rte_node_logtype;
>  #define NODE_LOG(level, node_name, ...)                                        \
> @@ -21,7 +22,6 @@ extern int rte_node_logtype;
>  #define node_dbg(node_name, ...) NODE_LOG(DEBUG, node_name, __VA_ARGS__)
>  
>  /**
> - *
>   * Node mbuf private data to store next hop, ttl and checksum.
>   */
>  struct node_mbuf_priv1 {
> @@ -37,6 +37,13 @@ struct node_mbuf_priv1 {
>  	};
>  };
>  
> +static const struct rte_mbuf_dynfield node_mbuf_priv1_dynfield_desc = {
> +	.name = "rte_node_dynfield_priv1",
> +	.size = sizeof(struct node_mbuf_priv1 *),
> +	.align = __alignof__(struct node_mbuf_priv1 *),
> +};
> +extern int node_mbuf_priv1_dynfield_offset;
> +
>  /**
>   * Node mbuf private area 2.
>   */
> @@ -60,7 +67,8 @@ struct node_mbuf_priv2 {
>  static __rte_always_inline struct node_mbuf_priv1 *
>  node_mbuf_priv1(struct rte_mbuf *m)
>  {
> -	return (struct node_mbuf_priv1 *)&m->udata64;
> +	return RTE_MBUF_DYNFIELD(m,
> +		node_mbuf_priv1_dynfield_offset, struct node_mbuf_priv1 *);

There is a performance regression of ~1.4% in our platform (Octeontx2) because
of this	change.

>  }
>  
>  /**
> -- 
> 2.28.0
>