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authorDavid Vrabel <david.vrabel@citrix.com>2014-10-22 14:08:55 +0100
committerDavid S. Miller <davem@davemloft.net>2014-10-25 14:15:20 -0400
commitecf08d2dbb96d5a4b4bcc53a39e8d29cc8fef02e (patch)
tree081341a32e4d7954ea805b145c18176876905ca7 /drivers/net/xen-netback/interface.c
parentf48da8b14d04ca87ffcffe68829afd45f926ec6a (diff)
downloadblackbird-obmc-linux-ecf08d2dbb96d5a4b4bcc53a39e8d29cc8fef02e.tar.gz
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xen-netback: reintroduce guest Rx stall detection
If a frontend not receiving packets it is useful to detect this and turn off the carrier so packets are dropped early instead of being queued and drained when they expire. A to-guest queue is stalled if it doesn't have enough free slots for a an extended period of time (default 60 s). If at least one queue is stalled, the carrier is turned off (in the expectation that the other queues will soon stall as well). The carrier is only turned on once all queues are ready. When the frontend connects, all the queues start in the stalled state and only become ready once the frontend queues enough Rx requests. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/xen-netback/interface.c')
-rw-r--r--drivers/net/xen-netback/interface.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index a134d52f55b4..895fe84011e7 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -419,6 +419,8 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
vif->queues = NULL;
vif->num_queues = 0;
+ spin_lock_init(&vif->lock);
+
dev->netdev_ops = &xenvif_netdev_ops;
dev->hw_features = NETIF_F_SG |
NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
@@ -505,7 +507,6 @@ void xenvif_carrier_on(struct xenvif *vif)
dev_set_mtu(vif->dev, ETH_DATA_LEN);
netdev_update_features(vif->dev);
set_bit(VIF_STATUS_CONNECTED, &vif->status);
- netif_carrier_on(vif->dev);
if (netif_running(vif->dev))
xenvif_up(vif);
rtnl_unlock();
@@ -565,6 +566,8 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
disable_irq(queue->rx_irq);
}
+ queue->stalled = true;
+
task = kthread_create(xenvif_kthread_guest_rx,
(void *)queue, "%s-guest-rx", queue->name);
if (IS_ERR(task)) {
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