svn commit: r301947 - stable/10/sys/dev/hyperv/netvsc

[Sepherosa Ziehau]

Author: sephe
Date: Thu Jun 16 03:16:43 2016
New Revision: 301947
URL: https://svnweb.freebsd.org/changeset/base/301947

Log:
  MFC 297180,297181,297182
  
  297180
      hyperv/hn: Reduce TCP segment aggregation limit for multiple RX rings
  
      This mainly used to improve ACK timeliness when multiple RX rings
      are enabled.
  
      This value gives the best performance in both Azure and Hyper-V
      environment, w/ both 10Ge and 40Ge using non-{INVARIANTS,WITNESS}
      kernel.
  
      MFC after:  1 week
      Sponsored by:       Microsoft OSTC
      Differential Revision:      https://reviews.freebsd.org/D5691
  
  297181
      hyperv/hn: Factor out hn_set_lro_lenlim()
  
      MFC after:  1 week
      Sponsored by:       Microsoft OSTC
      Differential Revision:      https://reviews.freebsd.org/D5692
  
  297182
      hyperv/hn: When short of mbufs on the RX path, don't spam the console.
  
      Instead, increase the IQDROPS counter.
  
      MFC after:  1 week
      Sponsored by:       Microsoft OSTC
      Differential Revision:      https://reviews.freebsd.org/D5693

Modified:
  stable/10/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
==============================================================================
--- stable/10/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c	Thu Jun 16 03:04:16 2016	(r301946)
+++ stable/10/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c	Thu Jun 16 03:16:43 2016	(r301947)
@@ -183,6 +183,7 @@ struct hn_txdesc {
 #define HN_CSUM_ASSIST_WIN8	(CSUM_IP | CSUM_TCP)
 #define HN_CSUM_ASSIST		(CSUM_IP | CSUM_UDP | CSUM_TCP)
 
+#define HN_LRO_LENLIM_MULTIRX_DEF	(12 * ETHERMTU)
 #define HN_LRO_LENLIM_DEF		(25 * ETHERMTU)
 /* YYY 2*MTU is a bit rough, but should be good enough. */
 #define HN_LRO_LENLIM_MIN(ifp)		(2 * (ifp)->if_mtu)
@@ -339,6 +340,17 @@ static void hn_xmit_txeof(struct hn_tx_r
 static void hn_xmit_taskfunc(void *, int);
 static void hn_xmit_txeof_taskfunc(void *, int);
 
+#if __FreeBSD_version >= 1100099
+static void
+hn_set_lro_lenlim(struct hn_softc *sc, int lenlim)
+{
+	int i;
+
+	for (i = 0; i < sc->hn_rx_ring_inuse; ++i)
+		sc->hn_rx_ring[i].hn_lro.lro_length_lim = lenlim;
+}
+#endif
+
 static int
 hn_ifmedia_upd(struct ifnet *ifp __unused)
 {
@@ -550,6 +562,16 @@ netvsc_attach(device_t dev)
 	device_printf(dev, "%d TX ring, %d RX ring\n",
 	    sc->hn_tx_ring_inuse, sc->hn_rx_ring_inuse);
 
+#if __FreeBSD_version >= 1100099
+	if (sc->hn_rx_ring_inuse > 1) {
+		/*
+		 * Reduce TCP segment aggregation limit for multiple
+		 * RX rings to increase ACK timeliness.
+		 */
+		hn_set_lro_lenlim(sc, HN_LRO_LENLIM_MULTIRX_DEF);
+	}
+#endif
+
 	if (device_info.link_state == 0) {
 		sc->hn_carrier = 1;
 	}
@@ -1258,8 +1280,10 @@ netvsc_recv(struct hv_vmbus_channel *cha
 		return (0);
 	} else if (packet->tot_data_buf_len <= MHLEN) {
 		m_new = m_gethdr(M_NOWAIT, MT_DATA);
-		if (m_new == NULL)
+		if (m_new == NULL) {
+			if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
 			return (0);
+		}
 		memcpy(mtod(m_new, void *), packet->data,
 		    packet->tot_data_buf_len);
 		m_new->m_pkthdr.len = m_new->m_len = packet->tot_data_buf_len;
@@ -1279,7 +1303,7 @@ netvsc_recv(struct hv_vmbus_channel *cha
 
 		m_new = m_getjcl(M_NOWAIT, MT_DATA, M_PKTHDR, size);
 		if (m_new == NULL) {
-			if_printf(ifp, "alloc mbuf failed.\n");
+			if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
 			return (0);
 		}
 
@@ -1469,13 +1493,8 @@ hn_ioctl(struct ifnet *ifp, u_long cmd, 
 		 */
 		NV_LOCK(sc);
 		if (sc->hn_rx_ring[0].hn_lro.lro_length_lim <
-		    HN_LRO_LENLIM_MIN(ifp)) {
-			int i;
-			for (i = 0; i < sc->hn_rx_ring_inuse; ++i) {
-				sc->hn_rx_ring[i].hn_lro.lro_length_lim =
-				    HN_LRO_LENLIM_MIN(ifp);
-			}
-		}
+		    HN_LRO_LENLIM_MIN(ifp))
+			hn_set_lro_lenlim(sc, HN_LRO_LENLIM_MIN(ifp));
 		NV_UNLOCK(sc);
 #endif
 
@@ -1808,7 +1827,7 @@ hn_lro_lenlim_sysctl(SYSCTL_HANDLER_ARGS
 {
 	struct hn_softc *sc = arg1;
 	unsigned int lenlim;
-	int error, i;
+	int error;
 
 	lenlim = sc->hn_rx_ring[0].hn_lro.lro_length_lim;
 	error = sysctl_handle_int(oidp, &lenlim, 0, req);
@@ -1820,8 +1839,7 @@ hn_lro_lenlim_sysctl(SYSCTL_HANDLER_ARGS
 		return EINVAL;
 
 	NV_LOCK(sc);
-	for (i = 0; i < sc->hn_rx_ring_inuse; ++i)
-		sc->hn_rx_ring[i].hn_lro.lro_length_lim = lenlim;
+	hn_set_lro_lenlim(sc, lenlim);
 	NV_UNLOCK(sc);
 	return 0;
 }