> when receive packets, it is possible to fail to reserve
> fill queue, since buffer ring is shared between tx and rx,
> and maybe not available temporary. at last, both fill
> queue and rx queue are empty.
>
> then kernel side will be unable to receive packets due to
> empty fill queue, and dpdk will be unable to reserve fill
> queue because dpdk has not pakcets to receive, at last
> deadlock will happen
>
> so move reserve fill queue before xsk_ring_cons__peek
> to fix it
>
> Signed-off-by: Li RongQing <lirongq...@baidu.com>
Thanks for the fix. I tested and saw no significant performance drop.
Minor: the first line of the commit should read "net/af_xdp: ...."
Acked-by: Ciara Loftus <ciara.lof...@intel.com>
CC-ing stable as I think this fix should be considered for inclusion.
Thanks,
Ciara
> ---
> drivers/net/af_xdp/rte_eth_af_xdp.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c
> b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index 7ce4ad04a..2dc9cab27 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -304,6 +304,10 @@ af_xdp_rx_cp(void *queue, struct rte_mbuf **bufs,
> uint16_t nb_pkts)
> uint32_t free_thresh = fq->size >> 1;
> struct rte_mbuf *mbufs[ETH_AF_XDP_RX_BATCH_SIZE];
>
> + if (xsk_prod_nb_free(fq, free_thresh) >= free_thresh)
> + (void)reserve_fill_queue(umem,
> ETH_AF_XDP_RX_BATCH_SIZE, NULL);
> +
> +
> if (unlikely(rte_pktmbuf_alloc_bulk(rxq->mb_pool, mbufs, nb_pkts)
> != 0))
> return 0;
>
> @@ -317,9 +321,6 @@ af_xdp_rx_cp(void *queue, struct rte_mbuf **bufs,
> uint16_t nb_pkts)
> goto out;
> }
>
> - if (xsk_prod_nb_free(fq, free_thresh) >= free_thresh)
> - (void)reserve_fill_queue(umem,
> ETH_AF_XDP_RX_BATCH_SIZE, NULL);
> -
> for (i = 0; i < rcvd; i++) {
> const struct xdp_desc *desc;
> uint64_t addr;
> --
> 2.16.2
