From 73cb2f38f2b26b43b308e42cb29c86ebb3f7303e Mon Sep 17 00:00:00 2001
From: "Andrey V. Elsukov" <ae@FreeBSD.org>
Date: Fri, 16 Nov 2012 12:12:02 +0000
Subject: [PATCH] Reduce the overhead of locking, use IF_AFDATA_RLOCK() when we
 are doing simple lookups.

Sponsored by:	Yandex LLC
MFC after:	1 week
---
 sys/netinet6/icmp6.c     |  4 ++--
 sys/netinet6/in6_src.c   |  4 ++--
 sys/netinet6/ip6_input.c |  4 ++--
 sys/netinet6/nd6.c       | 12 ++++++------
 sys/netinet6/nd6_rtr.c   | 12 ++++++------
 5 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c
index 9c2daa776837..d9ea93e20a82 100644
--- a/sys/netinet6/icmp6.c
+++ b/sys/netinet6/icmp6.c
@@ -2677,9 +2677,9 @@ icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
 		struct nd_opt_hdr *nd_opt;
 		char *lladdr;
 
-		IF_AFDATA_LOCK(ifp);
+		IF_AFDATA_RLOCK(ifp);
 		ln = nd6_lookup(router_ll6, 0, ifp);
-		IF_AFDATA_UNLOCK(ifp);
+		IF_AFDATA_RUNLOCK(ifp);
 		if (ln == NULL)
 			goto nolladdropt;
 
diff --git a/sys/netinet6/in6_src.c b/sys/netinet6/in6_src.c
index e028517e0c89..fb7e6f02a793 100644
--- a/sys/netinet6/in6_src.c
+++ b/sys/netinet6/in6_src.c
@@ -609,9 +609,9 @@ selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
 
 		rt = ron->ro_rt;
 		ifp = rt->rt_ifp;
-		IF_AFDATA_LOCK(ifp);
+		IF_AFDATA_RLOCK(ifp);
 		la = lla_lookup(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6_next->sin6_addr);
-		IF_AFDATA_UNLOCK(ifp);
+		IF_AFDATA_RUNLOCK(ifp);
 		if (la != NULL) 
 			LLE_RUNLOCK(la);
 		else {
diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c
index 3b501438fd5e..1b90c75dc29c 100644
--- a/sys/netinet6/ip6_input.c
+++ b/sys/netinet6/ip6_input.c
@@ -686,10 +686,10 @@ ip6_input(struct mbuf *m)
 	dst6.sin6_len = sizeof(struct sockaddr_in6);
 	dst6.sin6_addr = ip6->ip6_dst;
 	ifp = m->m_pkthdr.rcvif;
-	IF_AFDATA_LOCK(ifp);
+	IF_AFDATA_RLOCK(ifp);
 	lle = lla_lookup(LLTABLE6(ifp), 0,
 	     (struct sockaddr *)&dst6);
-	IF_AFDATA_UNLOCK(ifp);
+	IF_AFDATA_RUNLOCK(ifp);
 	if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) {
 		struct ifaddr *ifa;
 		struct in6_ifaddr *ia6;
diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 0ce73788dd3b..9993c7731b9e 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -975,12 +975,12 @@ nd6_is_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp)
 	 * Even if the address matches none of our addresses, it might be
 	 * in the neighbor cache.
 	 */
-	IF_AFDATA_LOCK(ifp);
+	IF_AFDATA_RLOCK(ifp);
 	if ((lle = nd6_lookup(&addr->sin6_addr, 0, ifp)) != NULL) {
 		LLE_RUNLOCK(lle);
 		rc = 1;
 	}
-	IF_AFDATA_UNLOCK(ifp);
+	IF_AFDATA_RUNLOCK(ifp);
 	return (rc);
 }
 
@@ -1480,9 +1480,9 @@ nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
 		if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
 			return (error);
 
-		IF_AFDATA_LOCK(ifp);
+		IF_AFDATA_RLOCK(ifp);
 		ln = nd6_lookup(&nb_addr, 0, ifp);
-		IF_AFDATA_UNLOCK(ifp);
+		IF_AFDATA_RUNLOCK(ifp);
 
 		if (ln == NULL) {
 			error = EINVAL;
@@ -2198,9 +2198,9 @@ nd6_storelladdr(struct ifnet *ifp, struct mbuf *m,
 	/*
 	 * the entry should have been created in nd6_store_lladdr
 	 */
-	IF_AFDATA_LOCK(ifp);
+	IF_AFDATA_RLOCK(ifp);
 	ln = lla_lookup(LLTABLE6(ifp), 0, dst);
-	IF_AFDATA_UNLOCK(ifp);
+	IF_AFDATA_RUNLOCK(ifp);
 	if ((ln == NULL) || !(ln->la_flags & LLE_VALID)) {
 		if (ln != NULL)
 			LLE_RUNLOCK(ln);
diff --git a/sys/netinet6/nd6_rtr.c b/sys/netinet6/nd6_rtr.c
index f346cdba8a76..f6bae0c04c6f 100644
--- a/sys/netinet6/nd6_rtr.c
+++ b/sys/netinet6/nd6_rtr.c
@@ -637,13 +637,13 @@ defrouter_select(void)
 	 * the ordering rule of the list described in defrtrlist_update().
 	 */
 	TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
-		IF_AFDATA_LOCK(dr->ifp);
+		IF_AFDATA_RLOCK(dr->ifp);
 		if (selected_dr == NULL &&
 		    (ln = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
 		    ND6_IS_LLINFO_PROBREACH(ln)) {
 			selected_dr = dr;
 		}
-		IF_AFDATA_UNLOCK(dr->ifp);
+		IF_AFDATA_RUNLOCK(dr->ifp);
 		if (ln != NULL) {
 			LLE_RUNLOCK(ln);
 			ln = NULL;
@@ -671,13 +671,13 @@ defrouter_select(void)
 		else
 			selected_dr = TAILQ_NEXT(installed_dr, dr_entry);
 	} else if (installed_dr) {
-		IF_AFDATA_LOCK(installed_dr->ifp);
+		IF_AFDATA_RLOCK(installed_dr->ifp);
 		if ((ln = nd6_lookup(&installed_dr->rtaddr, 0, installed_dr->ifp)) &&
 		    ND6_IS_LLINFO_PROBREACH(ln) &&
 		    rtpref(selected_dr) <= rtpref(installed_dr)) {
 			selected_dr = installed_dr;
 		}
-		IF_AFDATA_UNLOCK(installed_dr->ifp);
+		IF_AFDATA_RUNLOCK(installed_dr->ifp);
 		if (ln != NULL)
 			LLE_RUNLOCK(ln);
 	}
@@ -1301,9 +1301,9 @@ find_pfxlist_reachable_router(struct nd_prefix *pr)
 	int canreach;
 
 	LIST_FOREACH(pfxrtr, &pr->ndpr_advrtrs, pfr_entry) {
-		IF_AFDATA_LOCK(pfxrtr->router->ifp);
+		IF_AFDATA_RLOCK(pfxrtr->router->ifp);
 		ln = nd6_lookup(&pfxrtr->router->rtaddr, 0, pfxrtr->router->ifp);
-		IF_AFDATA_UNLOCK(pfxrtr->router->ifp);
+		IF_AFDATA_RUNLOCK(pfxrtr->router->ifp);
 		if (ln == NULL)
 			continue;
 		canreach = ND6_IS_LLINFO_PROBREACH(ln);