[dpdk-dev] [PATCH 0/3] net: fix out of order rx read issue

[dpdk-dev] [PATCH 0/3] net: fix out of order rx read issue

[Qi Zhang]

Volatile point has been cast to non-volatile
point when call _mm_loadu_si128, so add compile
barrier to prevent compiler reorder.

Qi Zhang (3):
  net/i40e: fix out of order rx read issue
  net/ixgbe: fix out of order rx read issue
  net/fm10k: fix out of order rx read issue

 drivers/net/fm10k/fm10k_rxtx_vec.c     | 3 +++
 drivers/net/i40e/i40e_rxtx_vec.c       | 3 +++
 drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c | 3 +++
 3 files changed, 9 insertions(+)

-- 
2.7.4

[dpdk-dev] [PATCH 1/3] net/i40e: fix out of order rx read issue

[Qi Zhang]

Volatile point has been cast to non-volatile
point when call _mm_loadu_si128, so add compile
barrier to prevent compiler reorder.

Fixes: 9ed94e5bb04e ("i40e: add vector Rx")

Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
---
 drivers/net/i40e/i40e_rxtx_vec.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/i40e/i40e_rxtx_vec.c b/drivers/net/i40e/i40e_rxtx_vec.c
index 0ee0241..ab63501 100644
--- a/drivers/net/i40e/i40e_rxtx_vec.c
+++ b/drivers/net/i40e/i40e_rxtx_vec.c
@@ -305,6 +305,7 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		/* Read desc statuses backwards to avoid race condition */
 		/* A.1 load 4 pkts desc */
 		descs[3] = _mm_loadu_si128((__m128i *)(rxdp + 3));
+		rte_compiler_barrier();
 
 		/* B.2 copy 2 mbuf point into rx_pkts  */
 		_mm_storeu_si128((__m128i *)&rx_pkts[pos], mbp1);
@@ -313,8 +314,10 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		mbp2 = _mm_loadu_si128((__m128i *)&sw_ring[pos+2]);
 
 		descs[2] = _mm_loadu_si128((__m128i *)(rxdp + 2));
+		rte_compiler_barrier();
 		/* B.1 load 2 mbuf point */
 		descs[1] = _mm_loadu_si128((__m128i *)(rxdp + 1));
+		rte_compiler_barrier();
 		descs[0] = _mm_loadu_si128((__m128i *)(rxdp));
 
 		/* B.2 copy 2 mbuf point into rx_pkts  */
-- 
2.7.4

[dpdk-dev] [PATCH 2/3] net/ixgbe: fix out of order rx read issue

[Qi Zhang]

Volatile point has been cast to non-volatile
point when call _mm_loadu_si128, so add compile
barrier to prevent compiler reorder.

Fixes: c95584dc2b18 ("ixgbe: new vectorized functions for Rx/Tx")

Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
---
 drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c b/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
index ad8a9ff..abbf284 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
@@ -343,6 +343,7 @@ _recv_raw_pkts_vec(struct ixgbe_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		/* Read desc statuses backwards to avoid race condition */
 		/* A.1 load 4 pkts desc */
 		descs[3] = _mm_loadu_si128((__m128i *)(rxdp + 3));
+		rte_compiler_barrier();
 
 		/* B.2 copy 2 mbuf point into rx_pkts  */
 		_mm_storeu_si128((__m128i *)&rx_pkts[pos], mbp1);
@@ -351,8 +352,10 @@ _recv_raw_pkts_vec(struct ixgbe_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		mbp2 = _mm_loadu_si128((__m128i *)&sw_ring[pos+2]);
 
 		descs[2] = _mm_loadu_si128((__m128i *)(rxdp + 2));
+		rte_compiler_barrier();
 		/* B.1 load 2 mbuf point */
 		descs[1] = _mm_loadu_si128((__m128i *)(rxdp + 1));
+		rte_compiler_barrier();
 		descs[0] = _mm_loadu_si128((__m128i *)(rxdp));
 
 		/* B.2 copy 2 mbuf point into rx_pkts  */
-- 
2.7.4

[dpdk-dev] [PATCH 3/3] net/fm10k: fix out of order rx read issue

[Qi Zhang]

Volatile point has been cast to non-volatile
point when call _mm_loadu_si128, so add compile
barrier to prevent compiler reorder.

Fixes: 7092be8437bd ("fm10k: add vector RX")

Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
---
 drivers/net/fm10k/fm10k_rxtx_vec.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/fm10k/fm10k_rxtx_vec.c b/drivers/net/fm10k/fm10k_rxtx_vec.c
index b724486..27f3e43 100644
--- a/drivers/net/fm10k/fm10k_rxtx_vec.c
+++ b/drivers/net/fm10k/fm10k_rxtx_vec.c
@@ -478,6 +478,7 @@ fm10k_recv_raw_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
 		/* Read desc statuses backwards to avoid race condition */
 		/* A.1 load 4 pkts desc */
 		descs0[3] = _mm_loadu_si128((__m128i *)(rxdp + 3));
+		rte_compiler_barrier();
 
 		/* B.2 copy 2 mbuf point into rx_pkts  */
 		_mm_storeu_si128((__m128i *)&rx_pkts[pos], mbp1);
@@ -486,8 +487,10 @@ fm10k_recv_raw_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
 		mbp2 = _mm_loadu_si128((__m128i *)&mbufp[pos+2]);
 
 		descs0[2] = _mm_loadu_si128((__m128i *)(rxdp + 2));
+		rte_compiler_barrier();
 		/* B.1 load 2 mbuf point */
 		descs0[1] = _mm_loadu_si128((__m128i *)(rxdp + 1));
+		rte_compiler_barrier();
 		descs0[0] = _mm_loadu_si128((__m128i *)(rxdp));
 
 		/* B.2 copy 2 mbuf point into rx_pkts  */
-- 
2.7.4

Re: [dpdk-dev] [PATCH 0/3] net: fix out of order rx read issue

[Chen, Jing D]

Hi,

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Qi Zhang
> Sent: Monday, October 17, 2016 1:24 AM
> To: Wu, Jingjing <jingjing.wu@intel.com>; Zhang, Helin
> <helin.zhang@intel.com>
> Cc: dev@dpdk.org; Zhang, Qi Z <qi.z.zhang@intel.com>
> Subject: [dpdk-dev] [PATCH 0/3] net: fix out of order rx read issue
> 
> Volatile point has been cast to non-volatile point when call _mm_loadu_si128,
> so add compile barrier to prevent compiler reorder.
> 
> Qi Zhang (3):
>   net/i40e: fix out of order rx read issue
>   net/ixgbe: fix out of order rx read issue
>   net/fm10k: fix out of order rx read issue
> 
>  drivers/net/fm10k/fm10k_rxtx_vec.c     | 3 +++
>  drivers/net/i40e/i40e_rxtx_vec.c       | 3 +++
>  drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c | 3 +++
>  3 files changed, 9 insertions(+)

I have an overall comment on the committed message. You'd better to describe
why we have out of order issue here and the requirement on the execution order
of the 4 loads.