Introduce `rt_lock' rwlock(9) and use it instead of kernel lock to

serialize arpcache() and arpresolve(). In fact, net stack already has
sleep points, so the rwlock(9) is better here because we avoid
intersection with the rest of kernel locked paths. Also this new lock
assumed to use to route layer protection instead of netlock.

Hrvoje Popovski had tested this diff and found no visible performance
impact.

ok bluhm@

1 files changed, 8 insertions, 1 deletions

diff --git a/sys/net/route.h b/sys/net/route.h
index 2178e401731..4c0c38577dc 100644
--- a/sys/net/route.h
+++ b/sys/net/route.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: route.h,v 1.196 2022/06/28 10:01:13 bluhm Exp $	*/
+/*	$OpenBSD: route.h,v 1.197 2023/01/21 17:35:01 mvs Exp $	*/
 /*	$NetBSD: route.h,v 1.9 1996/02/13 22:00:49 christos Exp $	*/
 
 /*
@@ -383,6 +383,13 @@ struct rt_addrinfo {
 #ifdef _KERNEL
 
 #include <sys/percpu.h>
+#include <sys/rwlock.h>
+
+extern struct rwlock rt_lock;
+
+#define RT_LOCK() rw_enter_write(&rt_lock)
+#define RT_UNLOCK() rw_exit_write(&rt_lock)
+#define RT_ASSERT_LOCKED() rw_assert_wrlock(&rt_lock)
 
 enum rtstat_counters {
 	rts_badredirect,	/* bogus redirect calls */