[PATCH v3] kni: optimize alloc queue release

[Jayatheerthan, Jay]

> -----Original Message-----
> From: Naga Harish K, S V <s.v.naga.harish.k at intel.com>
> Sent: Wednesday, April 13, 2022 8:27 PM
> To: ferruh.yigit at xilinx.com; Yigit, Ferruh <ferruh.yigit at intel.com>
> Cc: Jayatheerthan, Jay <jay.jayatheerthan at intel.com>; dev at dpdk.org
> Subject: [PATCH v3] kni: optimize alloc queue release
> 
> the kni alloc queue is filled with physical addresses of mbufs

nitpick: "The" instead of "the".

> for kernel consumption. Any unused mbufs in the alloc queue are
> freed during shutdown sequence in rte_kni_release.
> 
> In the current existing implementation, for freeing one entry of

nitpick: current and existing are redundant. Can keep one.

> alloc queue all the objects of the mempool are traversed. This
> process is repeated for all the objects of the alloc queue which
> consumes lot of cpu cycles.
> 
> Instead of using mempool object iteration method,use
> ``rte_mem_iova2virt()`` api to get the virtual address
> for the physical addresses of alloc_q objects.
> This speeds up the freeing process.
> 
> Signed-off-by: Naga Harish K S V <s.v.naga.harish.k at intel.com>
> ---
> v2:
> * fix checkpatch errors
> 
> v3:
> * fix commit message as per review comments
> ---
>  lib/kni/rte_kni.c | 23 ++++++++---------------
>  1 file changed, 8 insertions(+), 15 deletions(-)
> 
> diff --git a/lib/kni/rte_kni.c b/lib/kni/rte_kni.c
> index 7971c56bb4..f443e5b2fc 100644
> --- a/lib/kni/rte_kni.c
> +++ b/lib/kni/rte_kni.c
> @@ -375,26 +375,19 @@ va2pa_all(struct rte_mbuf *mbuf)
>  }
> 
>  static void
> -obj_free(struct rte_mempool *mp __rte_unused, void *opaque, void *obj,
> -		unsigned obj_idx __rte_unused)
> -{
> -	struct rte_mbuf *m = obj;
> -	void *mbuf_phys = opaque;
> -
> -	if (va2pa(m) == mbuf_phys)
> -		rte_pktmbuf_free(m);
> -}
> -
> -static void
> -kni_free_fifo_phy(struct rte_mempool *mp, struct rte_kni_fifo *fifo)
> +kni_free_fifo_phy(struct rte_kni_fifo *fifo)
>  {
>  	void *mbuf_phys;
>  	int ret;
> +	struct rte_mbuf *m;
> 
>  	do {
>  		ret = kni_fifo_get(fifo, &mbuf_phys, 1);
> -		if (ret)
> -			rte_mempool_obj_iter(mp, obj_free, mbuf_phys);
> +		if (ret) {
> +			m = (struct rte_mbuf *)
> +				rte_mem_iova2virt((rte_iova_t)mbuf_phys);
> +			rte_pktmbuf_free(m);
> +		}
>  	} while (ret);
>  }
> 
> @@ -440,7 +433,7 @@ rte_kni_release(struct rte_kni *kni)
>  	if (kni_fifo_count(kni->rx_q))
>  		RTE_LOG(ERR, KNI, "Fail to free all Rx-q items\n");
> 
> -	kni_free_fifo_phy(kni->pktmbuf_pool, kni->alloc_q);
> +	kni_free_fifo_phy(kni->alloc_q);
>  	kni_free_fifo(kni->tx_q);
>  	kni_free_fifo(kni->free_q);
> 
> --
> 2.23.0