There are some high performance NICs that count statistics in hardware,

and there are ifnets, that do that via counter(9). Provide a flag that
would skip cache line trashing '+=' operation in ether_input().

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
Reviewed by:	melifaro, adrian
Approved by:	re (marius)

5 files changed, 7 insertions, 3 deletions

diff --git a/sys/dev/cxgbe/t4_main.c b/sys/dev/cxgbe/t4_main.c
index d905cd5..c46ed5a0 100644
--- a/sys/dev/cxgbe/t4_main.c
+++ b/sys/dev/cxgbe/t4_main.c
@@ -950,7 +950,7 @@ cxgbe_probe(device_t dev)
 
 #define T4_CAP (IFCAP_VLAN_HWTAGGING | IFCAP_VLAN_MTU | IFCAP_HWCSUM | \
     IFCAP_VLAN_HWCSUM | IFCAP_TSO | IFCAP_JUMBO_MTU | IFCAP_LRO | \
-    IFCAP_VLAN_HWTSO | IFCAP_LINKSTATE | IFCAP_HWCSUM_IPV6)
+    IFCAP_VLAN_HWTSO | IFCAP_LINKSTATE | IFCAP_HWCSUM_IPV6 | IFCAP_HWSTATS)
 #define T4_CAP_ENABLE (T4_CAP)
 
 static int
diff --git a/sys/dev/ixgbe/ixgbe.c b/sys/dev/ixgbe/ixgbe.c
index 3434125..e913bd5 100644
--- a/sys/dev/ixgbe/ixgbe.c
+++ b/sys/dev/ixgbe/ixgbe.c
@@ -2662,7 +2662,8 @@ ixgbe_setup_interface(device_t dev, struct adapter *adapter)
 	ifp->if_capabilities |= IFCAP_LRO;
 	ifp->if_capabilities |= IFCAP_VLAN_HWTAGGING
 			     |  IFCAP_VLAN_HWTSO
-			     |  IFCAP_VLAN_MTU;
+			     |  IFCAP_VLAN_MTU
+			     |  IFCAP_HWSTATS;
 	ifp->if_capenable = ifp->if_capabilities;
 
 	/*
diff --git a/sys/net/if.h b/sys/net/if.h
index ab98ec0..80a7112 100644
--- a/sys/net/if.h
+++ b/sys/net/if.h
@@ -231,6 +231,7 @@ struct if_data {
 #define	IFCAP_NETMAP		0x100000 /* netmap mode supported/enabled */
 #define	IFCAP_RXCSUM_IPV6	0x200000  /* can offload checksum on IPv6 RX */
 #define	IFCAP_TXCSUM_IPV6	0x400000  /* can offload checksum on IPv6 TX */
+#define	IFCAP_HWSTATS		0x800000 /* manages counters internally */
 
 #define IFCAP_HWCSUM_IPV6	(IFCAP_RXCSUM_IPV6 | IFCAP_TXCSUM_IPV6)
 
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 638b364..d5c5521 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -528,7 +528,8 @@ ether_input_internal(struct ifnet *ifp, struct mbuf *m)
 		m->m_flags &= ~M_HASFCS;
 	}
 
-	ifp->if_ibytes += m->m_pkthdr.len;
+	if (!(ifp->if_capenable & IFCAP_HWSTATS))
+		ifp->if_ibytes += m->m_pkthdr.len;
 
 	/* Allow monitor mode to claim this frame, after stats are updated. */
 	if (ifp->if_flags & IFF_MONITOR) {
diff --git a/sys/net/if_lagg.c b/sys/net/if_lagg.c
index 27bab87..258c2f9 100644
--- a/sys/net/if_lagg.c
+++ b/sys/net/if_lagg.c
@@ -347,6 +347,7 @@ lagg_clone_create(struct if_clone *ifc, int unit, caddr_t params)
 	ifp->if_init = lagg_init;
 	ifp->if_ioctl = lagg_ioctl;
 	ifp->if_flags = IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST;
+	ifp->if_capenable = ifp->if_capabilities = IFCAP_HWSTATS;
 
 	/*
 	 * Attach as an ordinary ethernet device, children will be attached