NTB: MFV 9891417d: Increase transport MTU to 64k from 16k

Benchmarking showed a significant performance increase with the MTU size
to 64k instead of 16k.  Change the driver default to 64k.

Authored by:	Dave Jiang
Obtained from:	Linux (Dual BSD/GPL driver)
Sponsored by:	EMC / Isilon Storage Division

diff --git a/sys/dev/ntb/if_ntb/if_ntb.c b/sys/dev/ntb/if_ntb/if_ntb.c
index 3f33628b4bbf8ea77f2be13e0787a5dded1e2b61..7e6fe2272513201af6a30ab1c8dd81bca6e7c4d6 100644 (file)
--- a/sys/dev/ntb/if_ntb/if_ntb.c
+++ b/sys/dev/ntb/if_ntb/if_ntb.c
@@ -90,7 +90,7 @@ enum ntb_link_event {
        NTB_LINK_UP,
 };
 
-static unsigned int transport_mtu = 0x4000 + ETHER_HDR_LEN + ETHER_CRC_LEN;
+static unsigned int transport_mtu = 0x10000 + ETHER_HDR_LEN + ETHER_CRC_LEN;
 
 static uint64_t max_mw_size;
 SYSCTL_UQUAD(_hw_ntb, OID_AUTO, max_mw_size, CTLFLAG_RDTUN, &max_mw_size, 0,