xen/netfront: remove unnecessary wmb

Message ID 20181109065359.14900-1-jian.w.wen@oracle.com
State Accepted
Delegated to: David Miller
Headers show
Series
  • xen/netfront: remove unnecessary wmb
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Commit Message

Jacob Wen Nov. 9, 2018, 6:53 a.m.
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY is already able to make sure backend sees
requests before req_prod is updated.

Signed-off-by: Jacob Wen <jian.w.wen@oracle.com>
---
 drivers/net/xen-netfront.c | 2 --
 1 file changed, 2 deletions(-)

Comments

Juergen Gross Nov. 9, 2018, 6:58 a.m. | #1
On 09/11/2018 07:53, Jacob Wen wrote:
> RING_PUSH_REQUESTS_AND_CHECK_NOTIFY is already able to make sure backend sees
> requests before req_prod is updated.
> 
> Signed-off-by: Jacob Wen <jian.w.wen@oracle.com>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen
Wei Liu Nov. 9, 2018, 10:52 a.m. | #2
On Fri, Nov 09, 2018 at 02:53:59PM +0800, Jacob Wen wrote:
> RING_PUSH_REQUESTS_AND_CHECK_NOTIFY is already able to make sure backend sees
> requests before req_prod is updated.
> 
> Signed-off-by: Jacob Wen <jian.w.wen@oracle.com>

Reviewed-by: Wei Liu <wei.liu2@citrix.com>
David Miller Nov. 9, 2018, 11:17 p.m. | #3
From: Jacob Wen <jian.w.wen@oracle.com>
Date: Fri,  9 Nov 2018 14:53:59 +0800

> RING_PUSH_REQUESTS_AND_CHECK_NOTIFY is already able to make sure backend sees
> requests before req_prod is updated.
> 
> Signed-off-by: Jacob Wen <jian.w.wen@oracle.com>

Applied to net-next.

Patch

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index f17f602e6171..a8303afa15f1 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -337,8 +337,6 @@  static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
 		return;
 	}
 
-	wmb();		/* barrier so backend seens requests */
-
 	RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
 	if (notify)
 		notify_remote_via_irq(queue->rx_irq);