* [PATCH v2 1/2] net/ixgbe: add vector Rx parameter check
@ 2021-12-02 9:20 Bin Zheng
0 siblings, 0 replies; 2+ messages in thread
From: Bin Zheng @ 2021-12-02 9:20 UTC (permalink / raw)
To: dev; +Cc: haiyue.wang, liangma, Bin Zheng, jia.guo, stable
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 application.
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 application !
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(+)
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
^ permalink raw reply [flat|nested] 2+ messages in thread
* [PATCH v2 1/2] net/ixgbe: add vector Rx parameter check
@ 2021-12-02 8:31 Bin Zheng
0 siblings, 0 replies; 2+ messages in thread
From: Bin Zheng @ 2021-12-02 8:31 UTC (permalink / raw)
To: zhengbin89740; +Cc: Bin Zheng, jia.guo, stable
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 application.
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 application !
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(+)
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
^ permalink raw reply [flat|nested] 2+ messages in thread
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