diff options
| author | Malcolm Crossley <malcolm.crossley@citrix.com> | 2016-01-26 17:12:44 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-01-28 16:08:55 -0800 |
| commit | 7d0105b5334b9722b7d33acad613096dfcf3330e (patch) | |
| tree | 8bde5a2cf9e108bc654ef84db8d7acccae8981a8 | |
| parent | 3b89624ab54b9dc2d92fc08ce2670e5f19ad8ec8 (diff) | |
| download | linux-7d0105b5334b9722b7d33acad613096dfcf3330e.tar.bz2 | |
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>
| -rw-r--r-- | drivers/net/xen-netfront.c | 15 |
1 files changed, 3 insertions, 12 deletions
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index d6abf191122a..96ccd4e943db 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); } |