From: "Wang, Haiyue" <haiyue.wang@intel.com>
To: Bin Zheng <zhengbin.89740@bytedance.com>, "dev@dpdk.org" <dev@dpdk.org>
Cc: "liangma@liangbit.com" <liangma@liangbit.com>,
"stable@dpdk.org" <stable@dpdk.org>
Subject: RE: [PATCH] net/ixgbe: add vector Rx parameter check
Date: Thu, 2 Dec 2021 05:33:25 +0000 [thread overview]
Message-ID: <DM4PR11MB551898CB3BE03F94673FE8CEF7699@DM4PR11MB5518.namprd11.prod.outlook.com> (raw)
In-Reply-To: <20211202031857.1808705-1-zhengbin.89740@bytedance.com>
> -----Original Message-----
> From: Bin Zheng <zhengbin.89740@bytedance.com>
> Sent: Thursday, December 2, 2021 11:19
> To: dev@dpdk.org
> Cc: Wang, Haiyue <haiyue.wang@intel.com>; liangma@liangbit.com; Bin Zheng
> <zhengbin.89740@bytedance.com>; jia.guo@intel.com; stable@dpdk.org
> Subject: [PATCH] net/ixgbe: add vector Rx parameter check
>
> Under the circumstance that `rx_tail` wrap back to zero
> and the advance speed of `rx_tail` is greater than `rxrearm_start`,
> `rx_tail` will catch up with `rxrearm_start` and surpass it.
> This may cause some mbufs be reused by applicaion.
>
> So we need to make some restrictions to ensure that
> `rx_tail` will not exceed `rxrearm_start`.
>
> e.g.
>
> RDH: 972 RDT: 991 rxrearm_nb: 991 rxrearm_start: 992 rx_tail: 959
> RDH: 1004 RDT: 1023 rxrearm_nb: 991 rxrearm_start: 0 rx_tail: 991
> RDH: 12 RDT: 31 rxrearm_nb: 991 rxrearm_start: 32 rx_tail: 1023
> RDH: 31 RDT: 63 rxrearm_nb: 960 rxrearm_start: 64 rx_tail: 0
> RDH: 95 RDT: 95 rxrearm_nb: 1016 rxrearm_start: 96 rx_tail: 88
> RDH: 95 RDT: 127 rxrearm_nb: 991 rxrearm_start: 128 rx_tail: 95
> ...
> RDH: 908 RDT: 927 rxrearm_nb: 991 rxrearm_start: 928 rx_tail: 895
> RDH: 940 RDT: 959 rxrearm_nb: 991 rxrearm_start: 960 rx_tail: 927
> RDH: 980 RDT: 991 rxrearm_nb: 991 rxrearm_start: 992 rx_tail: 959
> RDH: 991 RDT: 991 rxrearm_nb: 1026 rxrearm_start: 992 rx_tail: 994
>
> when `rx_tail` catches up with `rxrearm_start`,
> 2(994 - 992) mbufs be reused by applicaion !
>
> Bugzilla ID: 882
> Fixes: 5a3cca342417 ("net/ixgbe: fix vector Rx")
> Cc: jia.guo@intel.com
> Cc: stable@dpdk.org
>
> Signed-off-by: Bin Zheng <zhengbin.89740@bytedance.com>
> ---
> drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
Both ? Or ?
https://patchwork.dpdk.org/project/dpdk/patch/20211202031530.1808112-1-zhengbin.89740@bytedance.com/
https://patchwork.dpdk.org/project/dpdk/patch/20211202031857.1808705-1-zhengbin.89740@bytedance.com/
> diff --git a/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c b/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
> index 1eed949495..5811749b95 100644
> --- a/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
> +++ b/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
> @@ -364,6 +364,17 @@ _recv_raw_pkts_vec(struct ixgbe_rx_queue *rxq, struct rte_mbuf **rx_pkts,
> uint8_t vlan_flags;
> uint16_t udp_p_flag = 0; /* Rx Descriptor UDP header present */
>
> + /*
> + * Under the circumstance that `rx_tail` wrap back to zero
> + * and the advance speed of `rx_tail` is greater than `rxrearm_start`,
> + * `rx_tail` will catch up with `rxrearm_start` and surpass it.
> + * This may cause some mbufs be reused by applicaion.
> + *
> + * So we need to make some restrictions to ensure that
> + * `rx_tail` will not exceed `rxrearm_start`.
> + */
> + nb_pkts = RTE_MIN(nb_pkts, RTE_IXGBE_RXQ_REARM_THRESH);
> +
> /* nb_pkts has to be floor-aligned to RTE_IXGBE_DESCS_PER_LOOP */
> nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_IXGBE_DESCS_PER_LOOP);
>
> --
> 2.25.1
next prev parent reply other threads:[~2021-12-02 5:33 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-02 3:18 Bin Zheng
2021-12-02 5:33 ` Wang, Haiyue [this message]
-- strict thread matches above, loose matches on Subject: below --
2021-12-02 3:15 Bin Zheng
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