Run the ND6 expiry timer without kernel lock

Added in 2017 to
	Reduce contention on the NET_LOCK() by moving the nd6 address expiration
	task to the `softnettq`.

This should no longer be needed thanks to sys/net/if.c r1.652 in 2022:
	Activate parallel IP forwarding.  Start 4 softnet tasks.  Limit the
	usage to the number of CPUs.

Nothing in nd6_expire() or nd6_expire_timer_update() requires protection by
the kernel lock.

The interface list and per-interface address lists remain protected by the
net lock.

Tests by Hrvoje
OK mpi

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 4a6f4b4..e65eeb0 100644 (file)
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: nd6.c,v 1.248 2022/09/09 12:05:52 kn Exp $    */
+/*     $OpenBSD: nd6.c,v 1.249 2022/11/07 10:45:39 kn Exp $    */
 /*     $KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun Exp $   */
 
 /*
@@ -446,8 +446,6 @@ nd6_expire_timer_update(struct in6_ifaddr *ia6)
        time_t expire_time = INT64_MAX;
        int secs;
 
-       KERNEL_ASSERT_LOCKED();
-
        if (ia6->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME)
                expire_time = ia6->ia6_lifetime.ia6t_expire;
 
@@ -486,7 +484,6 @@ nd6_expire(void *unused)
 {
        struct ifnet *ifp;
 
-       KERNEL_LOCK();
        NET_LOCK();
 
        TAILQ_FOREACH(ifp, &ifnetlist, if_list) {
@@ -509,7 +506,6 @@ nd6_expire(void *unused)
        }
 
        NET_UNLOCK();
-       KERNEL_UNLOCK();
 }
 
 void