From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [PATCH] fix ceph async messenger runtime bug based
 on spdk/dpdk
Date: Wed, 13 Dec 2017 13:31:00 -0800
Message-ID: <20171213133100.530518bd@xeon-e3>
References: <1513193552-159561-1-git-send-email-chunmei.liu@intel.com>
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Cc: dev@dpdk.org
To: chunmei Liu <chunmei.liu@intel.com>
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On Wed, 13 Dec 2017 11:32:32 -0800
chunmei Liu <chunmei.liu@intel.com> wrote:

> diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
> index 1e07895..30fdbc1 100644
> --- a/drivers/net/ixgbe/ixgbe_rxtx.c
> +++ b/drivers/net/ixgbe/ixgbe_rxtx.c
> @@ -1589,6 +1589,7 @@ ixgbe_rx_alloc_bufs(struct ixgbe_rx_queue *rxq, bool reset_mbuf)
>  		}
>  
>  		rte_mbuf_refcnt_set(mb, 1);
> +		mb->next = NULL;
>  		mb->data_off = RTE_PKTMBUF_HEADROOM;
>  

This will have measurable performance impact because the next pointer is
on the second cache line.