Re: [dpdk-dev] [PATCH 2/3] kni: minor opto

["Zhang, Helin" <helin.zhang@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Jay Rolette
> Sent: Thursday, June 4, 2015 3:19 AM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH 2/3] kni: minor opto
The title is not so descriptive for the changes.
The change itself seems OK for me. Thanks!

- Helin

> 
> No reason to check out many entries are in kni->rx_q prior to actually pulling
> them from the fifo. You can't dequeue more than are there anyway. Max entries
> to dequeue is either the max batch size or however much space is available on
> kni->free_q (lesser of the two)
> 
> Signed-off-by: Jay Rolette <rolette@infiniteio.com>
> ---
>  lib/librte_eal/linuxapp/kni/kni_net.c | 21 ++++++++-------------
>  1 file changed, 8 insertions(+), 13 deletions(-)
> 
> diff --git a/lib/librte_eal/linuxapp/kni/kni_net.c
> b/lib/librte_eal/linuxapp/kni/kni_net.c
> index dd95db5..13ccbb8 100644
> --- a/lib/librte_eal/linuxapp/kni/kni_net.c
> +++ b/lib/librte_eal/linuxapp/kni/kni_net.c
> @@ -131,7 +131,7 @@ kni_net_rx_normal(struct kni_dev *kni)  {
>  	unsigned ret;
>  	uint32_t len;
> -	unsigned i, num, num_rq, num_fq;
> +	unsigned i, num, num_fq;
>  	struct rte_kni_mbuf *kva;
>  	struct rte_kni_mbuf *va[MBUF_BURST_SZ];
>  	void * data_kva;
> @@ -139,24 +139,19 @@ kni_net_rx_normal(struct kni_dev *kni)
>  	struct sk_buff *skb;
>  	struct net_device *dev = kni->net_dev;
> 
> -	/* Get the number of entries in rx_q */
> -	num_rq = kni_fifo_count(kni->rx_q);
> -
>  	/* Get the number of free entries in free_q */
> -	num_fq = kni_fifo_free_count(kni->free_q);
> -
> -	/* Calculate the number of entries to dequeue in rx_q */
> -	num = min(num_rq, num_fq);
> -	num = min(num, (unsigned)MBUF_BURST_SZ);
> -
> -	/* Return if no entry in rx_q and no free entry in free_q */
> -	if (num == 0)
> +	if ((num_fq = kni_fifo_free_count(kni->free_q)) == 0) {
> +		/* No room on the free_q, bail out */
>  		return;
> +	}
> +
> +	/* Calculate the number of entries to dequeue from rx_q */
> +	num = min(num_fq, (unsigned)MBUF_BURST_SZ);
> 
>  	/* Burst dequeue from rx_q */
>  	ret = kni_fifo_get(kni->rx_q, (void **)va, num);
>  	if (ret == 0)
> -		return; /* Failing should not happen */
> +		return;
> 
>  	/* Transfer received packets to netif */
>  	for (i = 0; i < num; i++) {
> --
> 2.3.2 (Apple Git-55)