[V2] net/af_xdp: avoid deadlock due to empty fill queue
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Commit Message
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
Acked-by: Ciara Loftus <ciara.loftus@intel.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Dongsheng Rong <rongdongsheng@baidu.com>
Cc: stable@dpdk.org
---
Comments
On 9/18/2020 12:32 PM, Li RongQing wrote:
> 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
>
> Cc: stable@dpdk.org
>
> Signed-off-by: Li RongQing <lirongqing@baidu.com>
> Signed-off-by: Dongsheng Rong <rongdongsheng@baidu.com>
> Acked-by: Ciara Loftus <ciara.loftus@intel.com>
Applied to dpdk-next-net/main, thanks.
cc stable@dpdk.org
change af_xdp: as net/af_xdp
drivers/net/af_xdp/rte_eth_af_xdp.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
@@ -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;