diff --git a/sysutils/lsof/Makefile b/sysutils/lsof/Makefile
index af50e60e4e36..2e7f7b397e2d 100644
--- a/sysutils/lsof/Makefile
+++ b/sysutils/lsof/Makefile
@@ -1,8 +1,8 @@
-# $NetBSD: Makefile,v 1.140 2021/11/11 00:49:34 gutteridge Exp $
+# $NetBSD: Makefile,v 1.141 2022/05/25 09:33:37 tnn Exp $
 
 DISTNAME=		lsof_4.91
 PKGNAME=		${DISTNAME:S/_/-/}
-PKGREVISION=		5
+PKGREVISION=		6
 CATEGORIES=		sysutils
 MASTER_SITES=		ftp://ftp.mirrorservice.org/sites/lsof.itap.purdue.edu/pub/tools/unix/lsof/
 MASTER_SITES+=		ftp://ftp.mirrorservice.org/sites/lsof.itap.purdue.edu/pub/tools/unix/lsof/OLD/
@@ -74,6 +74,7 @@ post-extract:
 	fi ; \
 	${TOOLS_PATH.bsdtar} -xf ${SRCBALL_NAME}.tar
 	cd ${WRKSRC} ; ${ECHO} "y" | ./Inventory || exit 1
+	${CP} ${FILESDIR}/rnmt.c ${WRKSRC}/lib/rnmt.c
 
 SPECIAL_PERMS+=		${PREFIX}/sbin/lsof ${REAL_ROOT_USER} ${REAL_GROUP} 2755
 
diff --git a/sysutils/lsof/distinfo b/sysutils/lsof/distinfo
index c36906e7b935..e9dbdefb9f97 100644
--- a/sysutils/lsof/distinfo
+++ b/sysutils/lsof/distinfo
@@ -1,14 +1,15 @@
-$NetBSD: distinfo,v 1.101 2022/02/27 02:13:44 gutteridge Exp $
+$NetBSD: distinfo,v 1.102 2022/05/25 09:33:37 tnn Exp $
 
 BLAKE2s (lsof_4.91.tar.bz2) = 77109e036c36f7d1483e69f2aae2314830dc4d2bdc3bf88a4031832f17e6afef
 SHA512 (lsof_4.91.tar.bz2) = 49f811941dd6303f7cb0655fddb8b1177af5d1b18f2bd1edfab09d2c128aea73daecf09c7a5375979c66ba764c88a6e70c9086b55c3634e3be01ab1aa12e9f92
 Size (lsof_4.91.tar.bz2) = 791734 bytes
-SHA1 (patch-aa) = 4469a5fed540e3c5635b6082efedc477ea96a382
+SHA1 (patch-aa) = 76523a6d3bdff93a835dc442114f2bd4a018f95e
 SHA1 (patch-ab) = 1501d8b0e6fd2c61949ba0d447c7b726655725c4
-SHA1 (patch-ac) = dac0fcdfee97d42c8f23684a4321519b9f8698d9
+SHA1 (patch-ac) = ab1dc4540452f413493c58b729c7c6de83abfb6a
 SHA1 (patch-ad) = 7f639e8832c2da8e498c33a38ecbc7b3d3a7430a
 SHA1 (patch-ae) = 3f4a7ce54c0646941fd86400f91a2d17e9d2354a
 SHA1 (patch-af) = 88b3d2b42c05e20c189fa00fd65f1f412fe54038
 SHA1 (patch-ag) = 99ab1c616604e9775522dbc70bfd6a7294964d0a
 SHA1 (patch-ah) = 2de22b9a3733f958298af5e33b66c0653c320f59
 SHA1 (patch-dialects_n+obsd_dnode1.c) = dc8c766760aca4eb2e7d7af3944260dd49795c09
+SHA1 (patch-lib_Makefile.skel) = abfb9d50eef60c5d43cbf4978bf179de0ebe371e
diff --git a/sysutils/lsof/files/rnmt.c b/sysutils/lsof/files/rnmt.c
new file mode 100644
index 000000000000..682e1be53613
--- /dev/null
+++ b/sysutils/lsof/files/rnmt.c
@@ -0,0 +1,229 @@
+/*
+ * Copyright (C) 2022  Tobias Nygren <tnn@NetBSD.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "../machine.h"
+
+#if defined(HASNCACHE) && defined(USE_LIB_RNMT)
+#include <sys/rbtree.h>
+#include <sys/vnode_impl.h>
+#include <err.h>
+
+#include "../lsof.h"
+
+/*
+ * rnmt.c - read NetBSD=>10-style red-black tree kernel name cache
+ */
+
+static int lnc_compare_nodes(void *, const void *, const void *);
+static int lnc_compare_key(void *, const void *, const void *);
+
+static rb_tree_t lnc_rbtree;
+
+/* local name cache entry */
+struct lnc {
+	struct rb_node lnc_tree;	/* red-black tree */
+	KA_T lnc_vp;			/* vnode address */
+	KA_T lnc_pvp;			/* parent vnode address */
+	const struct lnc *lnc_plnc;	/* parent lnc address */
+	int lnc_nlen;			/* name length */
+	char lnc_name[NCHNAMLEN + 1];	/* name */
+};
+
+static const rb_tree_ops_t lnc_rbtree_ops = {
+	.rbto_compare_nodes = lnc_compare_nodes,
+	.rbto_compare_key = lnc_compare_key,
+	.rbto_node_offset = offsetof(struct lnc, lnc_tree),
+	.rbto_context = NULL
+};
+
+static int
+lnc_compare_nodes(void *context, const void *node1, const void *node2)
+{
+	const struct lnc *lnc1 = node1;
+	const struct lnc *lnc2 = node2;
+
+	if (lnc1->lnc_vp < lnc2->lnc_vp) {
+		return -1;
+	}
+	if (lnc1->lnc_vp > lnc2->lnc_vp) {
+		return 1;
+	}
+
+	return 0;
+}
+
+static int
+lnc_compare_key(void *context, const void *node, const void *key)
+{
+	const struct lnc *lnc = node;
+	const KA_T vp = (KA_T)key;
+
+	if (lnc->lnc_vp < vp) {
+		return -1;
+	}
+	if (lnc->lnc_vp > vp) {
+		return 1;
+	}
+
+	return 0;
+}
+
+static struct lnc *
+ncache_enter_local(KA_T vp, KA_T pvp, const struct lnc *plnc, const struct namecache *nc)
+{
+	struct lnc *lnc;
+
+	lnc = malloc(sizeof(*lnc));
+	if (!lnc) {
+		errx(1, "can't allocate local name cache entry\n");
+	}
+	lnc->lnc_vp = vp;
+	lnc->lnc_pvp = pvp;
+	lnc->lnc_plnc = plnc;
+	lnc->lnc_nlen = nc->nc_nlen;
+	memcpy(lnc->lnc_name, nc->nc_name, lnc->lnc_nlen);
+	lnc->lnc_name[lnc->lnc_nlen] = 0;
+
+	rb_tree_insert_node(&lnc_rbtree, lnc);
+
+	return lnc;
+}
+
+static int
+sanity_check_vnode_impl(const struct vnode_impl *vi)
+{
+	if (vi->vi_vnode.v_type >= VBAD)
+		return -1;
+
+	return 0;
+}
+
+static int
+sanity_check_namecache(const struct namecache *nc)
+{
+	if (nc->nc_vp == NULL)
+		return -1;
+
+	if (nc->nc_nlen > NCHNAMLEN)
+		return -1;
+
+	if (nc->nc_nlen == 1 && nc->nc_name[0] == '.')
+		return -1;
+
+	if (nc->nc_nlen == 2 && nc->nc_name[0] == '.' && nc->nc_name[1] == '.')
+		return -1;
+
+	return 0;
+}
+
+static void
+ncache_walk(KA_T ncp, KA_T pvp, const struct lnc *plnc)
+{
+	struct l_nch *lc;
+	static struct vnode_impl vi;
+	static struct namecache nc;
+	struct lnc *lnc;
+	KA_T vp;
+	KA_T left, right;
+
+	if (kread(ncp, (char *)&nc, sizeof(nc))) {
+		return;
+	}
+	vp = (KA_T)nc.nc_vp;
+	if (kread(vp, (char *)&vi, sizeof(vi))) {
+		vi.vi_vnode.v_type = VBAD;
+	}
+	left = (KA_T)nc.nc_tree.rb_nodes[0];
+	right = (KA_T)nc.nc_tree.rb_nodes[1];
+	if (sanity_check_vnode_impl(&vi) == 0 && sanity_check_namecache(&nc) == 0) {
+		lnc = ncache_enter_local(vp, pvp, plnc, &nc);
+		if (vi.vi_vnode.v_type = VDIR && vi.vi_nc_tree.rbt_root != NULL) {
+			ncache_walk((KA_T)vi.vi_nc_tree.rbt_root, ncp, lnc);
+		}
+	}
+	if (left)
+		ncache_walk(left, pvp, plnc);
+	if (right)
+		ncache_walk(right, pvp, plnc);
+}
+
+void
+ncache_load()
+{
+	KA_T rootvnode_addr;
+	struct vnode_impl vi;
+
+	rootvnode_addr = (KA_T)0;
+	if (get_Nl_value("rootvnode", (struct drive_Nl *)NULL, &rootvnode_addr) < 0
+	    || !rootvnode_addr
+	    || kread((KA_T)rootvnode_addr, (char *)&rootvnode_addr, sizeof(rootvnode_addr))
+	    || kread((KA_T)rootvnode_addr, (char *)&vi, sizeof(vi))) {
+		errx(1, "can't read rootvnode\n");
+	}
+
+	rb_tree_init(&lnc_rbtree, &lnc_rbtree_ops);
+	ncache_walk((KA_T)vi.vi_nc_tree.rbt_root, 0, 0);
+}
+
+static void
+build_path(char **buf, size_t *remaining, const struct lnc *lnc)
+{
+	size_t len;
+
+	if (lnc == NULL)
+		return;
+
+	build_path(buf, remaining, lnc->lnc_plnc);
+	if (remaining == 0) {
+		return;
+	}
+	if (lnc->lnc_plnc != NULL) {
+		**buf = '/';
+		(*buf)++;
+	}
+	remaining--;
+	len = lnc->lnc_nlen;
+	if (*remaining < len)
+		len = *remaining;
+	memcpy(*buf, lnc->lnc_name, len);
+	*remaining -= len;
+	*buf += len;
+}
+
+char *
+ncache_lookup(char *buf, int blen, int *fp)
+{
+	const struct lnc *lnc;
+	char *p;
+	size_t remaining;
+
+	*fp = 0;
+	lnc = rb_tree_find_node(&lnc_rbtree, (void*)Lf->na);
+	if (lnc != NULL) {
+		p = buf;
+		remaining = blen;
+		build_path(&p, &remaining, lnc);
+		if (remaining == 0) {
+			buf[blen - 1] = 0;
+		} else {
+			*p = 0;
+		}
+		*fp = 1;
+		return buf;
+	}
+
+	return NULL;
+}
+#endif
diff --git a/sysutils/lsof/patches/patch-aa b/sysutils/lsof/patches/patch-aa
index 61f5628e9d57..1f9385d29857 100644
--- a/sysutils/lsof/patches/patch-aa
+++ b/sysutils/lsof/patches/patch-aa
@@ -1,7 +1,7 @@
-$NetBSD: patch-aa,v 1.28 2010/04/30 06:53:07 sbd Exp $
+$NetBSD: patch-aa,v 1.29 2022/05/25 09:33:37 tnn Exp $
 
---- dialects/n+obsd/machine.h.orig	2006-03-28 16:54:17.000000000 -0500
-+++ dialects/n+obsd/machine.h	2008-05-17 18:53:29.000000000 -0400
+--- dialects/n+obsd/machine.h.orig	2010-07-29 16:02:55.000000000 +0000
++++ dialects/n+obsd/machine.h
 @@ -41,6 +41,10 @@
  
  #include <sys/types.h>
@@ -13,3 +13,14 @@ $NetBSD: patch-aa,v 1.28 2010/04/30 06:53:07 sbd Exp $
  
  
  /*
+@@ -577,7 +581,9 @@
+ /* #define	USE_LIB_READMNT			1	   rmnt.c */
+ /* #define	USE_LIB_REGEX			1	   regex.c */
+ 
+-# if	(defined(OPENBSDV) && OPENBSDV>=2010) || (defined(NETBSDV) && NETBSDV>=1002000)
++#if (defined(NETBSDV) && NETBSDV>=9099000)
++#define	USE_LIB_RNMT				1	/* rnmt.c */
++# elif	(defined(OPENBSDV) && OPENBSDV>=2010) || (defined(NETBSDV) && NETBSDV>=1002000)
+ #define	USE_LIB_RNMH				1	/* rnmh.c */
+ # else	/* (defined(OPENBSDV) && OPENBSDV<2010) && (defined(NETBSDV) && NETBSDV<1002000) */
+ #define	USE_LIB_RNAM				1	/* rnam.c */
diff --git a/sysutils/lsof/patches/patch-ac b/sysutils/lsof/patches/patch-ac
index ee9b0696f688..d588570ac42a 100644
--- a/sysutils/lsof/patches/patch-ac
+++ b/sysutils/lsof/patches/patch-ac
@@ -1,8 +1,19 @@
-$NetBSD: patch-ac,v 1.29 2008/05/17 23:53:29 christos Exp $
+$NetBSD: patch-ac,v 1.30 2022/05/25 09:33:37 tnn Exp $
 
---- dialects/n+obsd/dstore.c.orig	2004-12-30 13:42:32.000000000 -0500
-+++ dialects/n+obsd/dstore.c	2008-05-17 19:35:34.000000000 -0400
-@@ -119,6 +119,8 @@
+--- dialects/n+obsd/dstore.c.orig	2004-12-30 18:42:32.000000000 +0000
++++ dialects/n+obsd/dstore.c
+@@ -48,7 +48,9 @@ struct file *Cfp;		/* current file's fil
+  */
+ 
+ struct drive_Nl Drive_Nl[] = {
+-
++#if (defined(NETBSDV) && NETBSDV>=9099000)
++	{ "rootvnode",	"rootvnode",	},
++#endif
+ #if	(defined(OPENBSDV) && OPENBSDV>=2010) || (defined(NETBSDV) && NETBSDV>=1002000)
+ 	{ X_NCACHE,	"_nchashtbl",	},
+ 	{ X_NCSIZE,	"_nchash"	},
+@@ -119,6 +121,8 @@ struct pff_tab Pof_tab[] = {
  
  # if	defined(UF_EXCLOSE)
  	{ (long)UF_EXCLOSE,	POF_CLOEXEC	},
diff --git a/sysutils/lsof/patches/patch-lib_Makefile.skel b/sysutils/lsof/patches/patch-lib_Makefile.skel
new file mode 100644
index 000000000000..c94ad7f60e92
--- /dev/null
+++ b/sysutils/lsof/patches/patch-lib_Makefile.skel
@@ -0,0 +1,24 @@
+$NetBSD: patch-lib_Makefile.skel,v 1.1 2022/05/25 09:33:37 tnn Exp $
+
+--- lib/Makefile.skel.orig	2001-02-13 02:12:22.000000000 +0000
++++ lib/Makefile.skel
+@@ -13,10 +13,10 @@ INCL=	${DINC}
+ HDR=	../lsof.h ../proto.h ../dlsof.h ../dproto.h ../machine.h
+ 
+ SRC=	ckkv.c cvfs.c dvch.c fino.c isfn.c lkud.c pdvn.c prfp.c \
+-	ptti.c rdev.c regex.c rmnt.c rnam.c rnch.c rnmh.c snpf.c
++	ptti.c rdev.c regex.c rmnt.c rnam.c rnch.c rnmh.c rnmt.c snpf.c
+ 
+ OBJ=	ckkv.o cvfs.o dvch.o fino.o isfn.o lkud.o pdvn.o prfp.o \
+-	ptti.o rdev.o regex.o rmnt.o rnam.o rnch.o rnmh.o snpf.o
++	ptti.o rdev.o regex.o rmnt.o rnam.o rnch.o rnmh.o rnmt.o snpf.o
+ 
+ all:	${LIB}
+ 
+@@ -59,4 +59,6 @@ rnch.o: ${HDR} rnch.c
+ 
+ rnmh.o: ${HDR} rnmh.c
+ 
++rnmt.o: ${HDR} rnmt.c
++
+ snpf.o: ${HDR} snpf.c