For macvlan, switch to use IFF_NO_QUEUE instead of tx_queue_len = 0.

For macvtap, after commit 6acf54f1cf0a6747bac9fea26f34cfc5a9029523
("macvtap: Add support of packet capture on macvtap
device."). Multiqueue macvtap suffers from single qdisc lock
contention. This is because macvtap claims a non zero tx_queue_len and
it reuses this value as it socket receive queue size.Thanks to
IFF_NO_QUEUE, we can remove the lock contention without breaking
existing socket receive queue length logic.

Cc: Patrick McHardy <ka...@trash.net>
Cc: Vladislav Yasevich <vyase...@redhat.com>
Cc: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Jason Wang <jasow...@redhat.com>
---
 drivers/net/macvlan.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 47da435..09d8718 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -1056,7 +1056,7 @@ void macvlan_common_setup(struct net_device *dev)
 
        dev->priv_flags        &= ~IFF_TX_SKB_SHARING;
        netif_keep_dst(dev);
-       dev->priv_flags        |= IFF_UNICAST_FLT;
+       dev->priv_flags        |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
        dev->netdev_ops         = &macvlan_netdev_ops;
        dev->destructor         = free_netdev;
        dev->header_ops         = &macvlan_hard_header_ops;
@@ -1067,7 +1067,6 @@ EXPORT_SYMBOL_GPL(macvlan_common_setup);
 static void macvlan_setup(struct net_device *dev)
 {
        macvlan_common_setup(dev);
-       dev->tx_queue_len       = 0;
 }
 
 static int macvlan_port_create(struct net_device *dev)
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to