svn commit: r298563 - head/sys/dev/hyperv/netvsc

[Sepherosa Ziehau]

Author: sephe
Date: Mon Apr 25 03:48:28 2016
New Revision: 298563
URL: https://svnweb.freebsd.org/changeset/base/298563

Log:
  hyperv/hn: Allow users to configure ifq or bufring depth.
  
  MFC after:	1 week
  Sponsored by:	Microsoft OSTC

Modified:
  head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c

Modified: head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
==============================================================================
--- head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c	Mon Apr 25 03:24:48 2016	(r298562)
+++ head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c	Mon Apr 25 03:48:28 2016	(r298563)
@@ -291,6 +291,10 @@ static int hn_tx_ring_cnt = 0;
 SYSCTL_INT(_hw_hn, OID_AUTO, tx_ring_cnt, CTLFLAG_RDTUN,
     &hn_tx_ring_cnt, 0, "# of TX rings to use");
 
+static int hn_tx_swq_depth = 0;
+SYSCTL_INT(_hw_hn, OID_AUTO, tx_swq_depth, CTLFLAG_RDTUN,
+    &hn_tx_swq_depth, 0, "Depth of IFQ or BUFRING");
+
 static u_int hn_cpu_index;
 
 /*
@@ -348,6 +352,16 @@ hn_set_lro_lenlim(struct hn_softc *sc, i
 #endif
 
 static int
+hn_get_txswq_depth(const struct hn_tx_ring *txr)
+{
+
+	KASSERT(txr->hn_txdesc_cnt > 0, ("tx ring is not setup yet"));
+	if (hn_tx_swq_depth < txr->hn_txdesc_cnt)
+		return txr->hn_txdesc_cnt;
+	return hn_tx_swq_depth;
+}
+
+static int
 hn_ifmedia_upd(struct ifnet *ifp __unused)
 {
 
@@ -501,9 +515,11 @@ netvsc_attach(device_t dev)
 	/* needed by hv_rf_on_device_add() code */
 	ifp->if_mtu = ETHERMTU;
 	if (hn_use_if_start) {
+		int qdepth = hn_get_txswq_depth(&sc->hn_tx_ring[0]);
+
 		ifp->if_start = hn_start;
-		IFQ_SET_MAXLEN(&ifp->if_snd, 512);
-		ifp->if_snd.ifq_drv_maxlen = 511;
+		IFQ_SET_MAXLEN(&ifp->if_snd, qdepth);
+		ifp->if_snd.ifq_drv_maxlen = qdepth - 1;
 		IFQ_SET_READY(&ifp->if_snd);
 	} else {
 		ifp->if_transmit = hn_transmit;
@@ -2285,10 +2301,14 @@ hn_create_tx_ring(struct hn_softc *sc, i
 		TASK_INIT(&txr->hn_tx_task, 0, hn_start_taskfunc, txr);
 		TASK_INIT(&txr->hn_txeof_task, 0, hn_start_txeof_taskfunc, txr);
 	} else {
+		int br_depth;
+
 		txr->hn_txeof = hn_xmit_txeof;
 		TASK_INIT(&txr->hn_tx_task, 0, hn_xmit_taskfunc, txr);
 		TASK_INIT(&txr->hn_txeof_task, 0, hn_xmit_txeof_taskfunc, txr);
-		txr->hn_mbuf_br = buf_ring_alloc(txr->hn_txdesc_cnt, M_NETVSC,
+
+		br_depth = hn_get_txswq_depth(txr);
+		txr->hn_mbuf_br = buf_ring_alloc(br_depth, M_NETVSC,
 		    M_WAITOK, &txr->hn_tx_lock);
 	}