[PATCH] net/intel: allow fast-free to empty cache

[Morten Brørup]

> From: Bruce Richardson [mailto:bruce.richardson at intel.com]
> Sent: Monday, 10 March 2025 14.26
> 
> When freeing transmitted mbufs, there is no reason to send the freed
> mbufs directly to the ring if the cache is empty - only if it is zero
> size (in which case the cache pointer is NULL). Therefore, remove the
> empty check and only check for a null cache pointer.
> 
> Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
> ---
>  drivers/net/intel/common/tx.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/intel/common/tx.h
> b/drivers/net/intel/common/tx.h
> index d9cf4474fc..d361fe64ab 100644
> --- a/drivers/net/intel/common/tx.h
> +++ b/drivers/net/intel/common/tx.h
> @@ -143,7 +143,7 @@ ci_tx_free_bufs_vec(struct ci_tx_queue *txq,
> ci_desc_done_fn desc_done, bool ctx
>  		void **cache_objs;
>  		struct rte_mempool_cache *cache =
> rte_mempool_default_cache(mp, rte_lcore_id());
> 
> -		if (!cache || cache->len == 0)
> +		if (cache == NULL)
>  			goto normal;
> 
>  		cache_objs = &cache->objs[cache->len];
> --
> 2.43.0

Yep, it did look strange.
Reviewed-by: Morten Brørup <mb at smartsharesystems.com>