net: introduce netdevice gso_min_segs attribute

Some TSO engines might have a too heavy setup cost, that impacts
performance on hosts sending small bursts (2 MSS per packet).

This patch adds a device gso_min_segs, allowing drivers to set
a minimum segment size for TSO packets, according to the NIC
performance.

Tested on a mlx4 NIC, this allows to get a ~110% increase of
throughput when sending 2 MSS per packet.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2014-10-05 10:11:27 -07:00
committed by David S. Miller
parent 9d31a7b9f9
commit fcbeb976d7
2 changed files with 9 additions and 4 deletions

View File

@@ -1416,6 +1416,8 @@ enum netdev_priv_flags {
* @gso_max_size: Maximum size of generic segmentation offload
* @gso_max_segs: Maximum number of segments that can be passed to the
* NIC for GSO
* @gso_min_segs: Minimum number of segments that can be passed to the
* NIC for GSO
*
* @dcbnl_ops: Data Center Bridging netlink ops
* @num_tc: Number of traffic classes in the net device
@@ -1666,7 +1668,7 @@ struct net_device {
unsigned int gso_max_size;
#define GSO_MAX_SEGS 65535
u16 gso_max_segs;
u16 gso_min_segs;
#ifdef CONFIG_DCB
const struct dcbnl_rtnl_ops *dcbnl_ops;
#endif