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From: Joyce Kong <joyce.kong@arm.com>
To: beilei.xing@intel.com, qi.z.zhang@intel.com,
	ruifeng.wang@arm.com, honnappa.nagarahalli@arm.com,
	bruce.richardson@intel.com, helin.zhang@intel.com
Cc: dev@dpdk.org, stable@dpdk.org, nd@arm.com
Subject: [dpdk-dev] [PATCH v3 2/2] net/i40e: replace SMP barrier with thread fence
Date: Tue,  6 Jul 2021 01:54:04 -0500	[thread overview]
Message-ID: <20210706065404.25137-3-joyce.kong@arm.com> (raw)
In-Reply-To: <20210706065404.25137-1-joyce.kong@arm.com>

Simply replace the SMP barrier with atomic thread fence for
i40e hw ring sacn, if there is no synchronization point.

Signed-off-by: Joyce Kong <joyce.kong@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
 drivers/net/i40e/i40e_rxtx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index 9aaabfd92..86e2f083e 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -482,7 +482,8 @@ i40e_rx_scan_hw_ring(struct i40e_rx_queue *rxq)
 					I40E_RXD_QW1_STATUS_SHIFT;
 		}
 
-		rte_smp_rmb();
+		/* This barrier is to order loads of different words in the descriptor */
+		rte_atomic_thread_fence(__ATOMIC_ACQUIRE);
 
 		/* Compute how many status bits were set */
 		for (j = 0, nb_dd = 0; j < I40E_LOOK_AHEAD; j++) {
-- 
2.17.1


  parent reply	other threads:[~2021-07-06  6:55 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-04  7:34 [dpdk-dev] [PATCH v1] net/i40e: remove the SMP barrier in HW scanning func Joyce Kong
2021-06-04 16:12 ` Honnappa Nagarahalli
2021-06-06 14:17 ` Zhang, Qi Z
2021-06-06 18:33   ` Honnappa Nagarahalli
2021-06-07 14:55     ` Zhang, Qi Z
2021-06-07 21:36       ` Honnappa Nagarahalli
2021-06-15  6:30         ` Joyce Kong
2021-06-16 13:29         ` Zhang, Qi Z
2021-06-16 13:37           ` Bruce Richardson
2021-06-16 20:26             ` Honnappa Nagarahalli
2021-06-23  8:43 ` [dpdk-dev] [PATCH v2] net/i40e: add logic of processing continuous DD bits for Arm Joyce Kong
2021-06-30  1:14   ` Honnappa Nagarahalli
2021-07-05  3:41     ` Joyce Kong
2021-07-06  6:54 ` [dpdk-dev] [PATCH v3 0/2] fixes for i40e hw scan ring Joyce Kong
2021-07-06  6:54   ` [dpdk-dev] [PATCH v3 1/2] net/i40e: add logic of processing continuous DD bits for Arm Joyce Kong
2021-07-09  3:05     ` Zhang, Qi Z
2021-07-06  6:54   ` Joyce Kong [this message]
2021-07-08 12:09     ` [dpdk-dev] [PATCH v3 2/2] net/i40e: replace SMP barrier with thread fence Zhang, Qi Z
2021-07-08 13:51       ` Lance Richardson
2021-07-08 14:26         ` Zhang, Qi Z
2021-07-08 14:44           ` Honnappa Nagarahalli
2021-07-13  0:46     ` Zhang, Qi Z

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