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>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 22d54b9..2df86f5 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1416,6 +1416,8 @@
* @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 @@
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
