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authorMalcolm Crossley <malcolm.crossley@citrix.com>2016-01-26 17:12:44 +0000
committerDavid S. Miller <davem@davemloft.net>2016-01-28 16:08:55 -0800
commit7d0105b5334b9722b7d33acad613096dfcf3330e (patch)
tree8bde5a2cf9e108bc654ef84db8d7acccae8981a8 /drivers/net/xen-netfront.c
parent3b89624ab54b9dc2d92fc08ce2670e5f19ad8ec8 (diff)
downloadop-kernel-dev-7d0105b5334b9722b7d33acad613096dfcf3330e.zip
op-kernel-dev-7d0105b5334b9722b7d33acad613096dfcf3330e.tar.gz
xen-netfront: request Tx response events more often
Trying to batch Tx response events results in poor performance because this delays freeing the transmitted skbs. Instead use the standard RING_FINAL_CHECK_FOR_RESPONSES() macro to be notified once the next Tx response is placed on the ring. Signed-off-by: Malcolm Crossley <malcolm.crossley@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/xen-netfront.c')
-rw-r--r--drivers/net/xen-netfront.c15
1 files changed, 3 insertions, 12 deletions
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index d6abf19..96ccd4e 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -364,6 +364,7 @@ static void xennet_tx_buf_gc(struct netfront_queue *queue)
RING_IDX cons, prod;
unsigned short id;
struct sk_buff *skb;
+ bool more_to_do;
BUG_ON(!netif_carrier_ok(queue->info->netdev));
@@ -398,18 +399,8 @@ static void xennet_tx_buf_gc(struct netfront_queue *queue)
queue->tx.rsp_cons = prod;
- /*
- * Set a new event, then check for race with update of tx_cons.
- * Note that it is essential to schedule a callback, no matter
- * how few buffers are pending. Even if there is space in the
- * transmit ring, higher layers may be blocked because too much
- * data is outstanding: in such cases notification from Xen is
- * likely to be the only kick that we'll get.
- */
- queue->tx.sring->rsp_event =
- prod + ((queue->tx.sring->req_prod - prod) >> 1) + 1;
- mb(); /* update shared area */
- } while ((cons == prod) && (prod != queue->tx.sring->rsp_prod));
+ RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
+ } while (more_to_do);
xennet_maybe_wake_tx(queue);
}
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