RE: [PATCH v2] kni: optimize alloc queue release

["Kundapura, Ganapati" <ganapati.kundapura@intel.com>]

Hi Harish

> -----Original Message-----
> From: Naga Harish K S V <s.v.naga.harish.k@intel.com>
> Sent: 13 April 2022 11:19
> To: Yigit, Ferruh <ferruh.yigit@intel.com>
> Cc: Jayatheerthan, Jay <jay.jayatheerthan@intel.com>; dev@dpdk.org
> Subject: [PATCH v2] kni: optimize alloc queue release
> 
> the kni alloc queue is filled with physical addresses of mbufs 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 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 sppeds up the freeing process.
Nitpick: speeds
> 
> Signed-off-by: Naga Harish K S V <s.v.naga.harish.k@intel.com>
> ---
> v2:
> * fix checkpatch errors
> ---
>  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