Only start the if_slowtimo timer (which drives the if_watchdog methods of

network interfaces) if we have at least one interface with an if_watchdog
routine.

MFC after:	2 weeks

1 files changed, 25 insertions, 2 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index 070202c..2fb8e23 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -97,6 +97,8 @@ struct vnet_net vnet_net_0;
 #endif
 #endif
 
+static int slowtimo_started;
+
 SYSCTL_NODE(_net, PF_LINK, link, CTLFLAG_RW, 0, "Link layers");
 SYSCTL_NODE(_net_link, 0, generic, CTLFLAG_RW, 0, "Generic link-management");
 
@@ -124,6 +126,7 @@ static int	ifconf(u_long, caddr_t);
 static void	if_freemulti(struct ifmultiaddr *);
 static void	if_grow(void);
 static void	if_init(void *);
+static void	if_check(void *);
 static void	if_qflush(struct ifnet *);
 static void	if_route(struct ifnet *, int flag, int fam);
 static int	if_setflag(struct ifnet *, int, int, int *, int);
@@ -185,7 +188,7 @@ VNET_MOD_DECLARE(NET, net, vnet_net_iattach, vnet_net_idetach,
  * System initialization
  */
 SYSINIT(interfaces, SI_SUB_INIT_IF, SI_ORDER_FIRST, if_init, NULL);
-SYSINIT(interface_check, SI_SUB_PROTO_IF, SI_ORDER_FIRST, if_slowtimo, NULL);
+SYSINIT(interface_check, SI_SUB_PROTO_IF, SI_ORDER_FIRST, if_check, NULL);
 
 MALLOC_DEFINE(M_IFNET, "ifnet", "interface internals");
 MALLOC_DEFINE(M_IFADDR, "ifaddr", "interface address");
@@ -425,6 +428,18 @@ if_grow(void)
 	V_ifindex_table = e;
 }
 
+static void
+if_check(void *dummy __unused)
+{
+
+	/*
+	 * If at least one interface added during boot uses
+	 * if_watchdog then start the timer.
+	 */
+	if (slowtimo_started)
+		if_slowtimo(0);
+}
+
 /*
  * Allocate a struct ifnet and an index for an interface.  A layer 2
  * common structure will also be allocated if an allocation routine is
@@ -647,9 +662,17 @@ if_attach(struct ifnet *ifp)
 	/* Announce the interface. */
 	rt_ifannouncemsg(ifp, IFAN_ARRIVAL);
 
-	if (ifp->if_watchdog != NULL)
+	if (ifp->if_watchdog != NULL) {
 		if_printf(ifp,
 		    "WARNING: using obsoleted if_watchdog interface\n");
+	      
+		/*
+		 * Note that we need if_slowtimo().  If this happens after
+		 * boot, then call if_slowtimo() directly.
+		 */
+		if (atomic_cmpset_int(&slowtimo_started, 0, 1) && !cold)
+			if_slowtimo(0);
+	}
 	if (ifp->if_flags & IFF_NEEDSGIANT)
 		if_printf(ifp,
 		    "WARNING: using obsoleted IFF_NEEDSGIANT flag\n");