[v4,1/2] net/ixgbe: calculate the correct number of received packets in bulk alloc function

Message ID 1486613126-30409-1-git-send-email-jianbo.liu@linaro.org
State New
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  • [v4,1/2] net/ixgbe: calculate the correct number of received packets in bulk alloc function
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Commit Message

Jianbo Liu Feb. 9, 2017, 4:05 a.m.
To get better performance, Rx bulk alloc recv function will scan 8 descs
in one time, but the statuses are not consistent on ARM platform because
the memory allocated for Rx descriptors is cacheable hugepages.
This patch is to calculate the number of received packets by scan DD bit
sequentially, and stops when meeting the first packet with DD bit unset.

Signed-off-by: Jianbo Liu <jianbo.liu@linaro.org>

---
 drivers/net/ixgbe/ixgbe_rxtx.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

-- 
1.8.3.1

Comments

Ferruh Yigit Feb. 9, 2017, 12:39 p.m. | #1
On 2/9/2017 4:05 AM, Jianbo Liu wrote:
> To get better performance, Rx bulk alloc recv function will scan 8 descs

> in one time, but the statuses are not consistent on ARM platform because

> the memory allocated for Rx descriptors is cacheable hugepages.

> This patch is to calculate the number of received packets by scan DD bit

> sequentially, and stops when meeting the first packet with DD bit unset.

> 

> Signed-off-by: Jianbo Liu <jianbo.liu@linaro.org>


    net/ixgbe: fix received packets number for ARM NEON

    Fixes: b20971b6cca0 ("net/ixgbe: implement vector driver for ARM")
    Cc: stable@dpdk.org

    Signed-off-by: Jianbo Liu <jianbo.liu@linaro.org>

    Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>



Applied to dpdk-next-net/master, thanks.
Ferruh Yigit Feb. 9, 2017, 12:42 p.m. | #2
On 2/9/2017 12:39 PM, Ferruh Yigit wrote:
> On 2/9/2017 4:05 AM, Jianbo Liu wrote:

>> To get better performance, Rx bulk alloc recv function will scan 8 descs

>> in one time, but the statuses are not consistent on ARM platform because

>> the memory allocated for Rx descriptors is cacheable hugepages.

>> This patch is to calculate the number of received packets by scan DD bit

>> sequentially, and stops when meeting the first packet with DD bit unset.

>>

>> Signed-off-by: Jianbo Liu <jianbo.liu@linaro.org>

> 

>     net/ixgbe: fix received packets number for ARM NEON

> 

>     Fixes: b20971b6cca0 ("net/ixgbe: implement vector driver for ARM")

>     Cc: stable@dpdk.org

> 

>     Signed-off-by: Jianbo Liu <jianbo.liu@linaro.org>

>     Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>


Correction:
    net/ixgbe: fix received packets number for ARM

    Fixes: 7431041062b9 ("ixgbe: allow rx bulk alloc")
    Cc: stable@dpdk.org

    Signed-off-by: Jianbo Liu <jianbo.liu@linaro.org>

    Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>


> 

> 

> Applied to dpdk-next-net/master, thanks.

>

Patch

diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
index 36f1c02..613890e 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx.c
@@ -1460,17 +1460,19 @@  static inline int __attribute__((always_inline))
 	for (i = 0; i < RTE_PMD_IXGBE_RX_MAX_BURST;
 	     i += LOOK_AHEAD, rxdp += LOOK_AHEAD, rxep += LOOK_AHEAD) {
 		/* Read desc statuses backwards to avoid race condition */
-		for (j = LOOK_AHEAD-1; j >= 0; --j)
+		for (j = 0; j < LOOK_AHEAD; j++)
 			s[j] = rte_le_to_cpu_32(rxdp[j].wb.upper.status_error);
 
-		for (j = LOOK_AHEAD - 1; j >= 0; --j)
-			pkt_info[j] = rte_le_to_cpu_32(rxdp[j].wb.lower.
-						       lo_dword.data);
+		rte_smp_rmb();
 
 		/* Compute how many status bits were set */
-		nb_dd = 0;
-		for (j = 0; j < LOOK_AHEAD; ++j)
-			nb_dd += s[j] & IXGBE_RXDADV_STAT_DD;
+		for (nb_dd = 0; nb_dd < LOOK_AHEAD &&
+				(s[nb_dd] & IXGBE_RXDADV_STAT_DD); nb_dd++)
+			;
+
+		for (j = 0; j < nb_dd; j++)
+			pkt_info[j] = rte_le_to_cpu_32(rxdp[j].wb.lower.
+						       lo_dword.data);
 
 		nb_rx += nb_dd;