[dpdk-dev] [PATCH v2] kni: add new mbuf in alloc_q only based on its empty slots

[Ferruh Yigit]

On 5/11/2017 12:51 PM, Gowrishankar wrote:
> From: Gowrishankar Muthukrishnan <gowrishankar.m at linux.vnet.ibm.com>
> 
> In kni_allocate_mbufs(), we attempt to add max_burst (32) count of mbuf
> always into alloc_q, which is excessively leading too many rte_pktmbuf_
> free() when alloc_q is contending at high packet rate (for eg 10Gig data).
> In a situation when alloc_q fifo can only accommodate very few (or zero)
> mbuf, create only what needed and add in fifo.
> 
> With this patch, we could stop random network stall in KNI at higher packet
> rate (eg 1G or 10G data between vEth0 and PMD) sufficiently exhausting
> alloc_q on above condition. I tested i40e PMD for this purpose in ppc64le.
> 
> Changes:
>  v2 - alloc_q free count calculation corrected.
>       line wrap fixed for commit message.
> 
> Signed-off-by: Gowrishankar Muthukrishnan <gowrishankar.m at linux.vnet.ibm.com>

Acked-by: Ferruh Yigit <ferruh.yigit at intel.com>