Index: sys/kern/kern_mbuf.c
===================================================================
--- sys/kern/kern_mbuf.c
+++ sys/kern/kern_mbuf.c
@@ -658,7 +658,8 @@
 	flags = (unsigned long)arg;
 
 	KASSERT((m->m_flags & M_NOFREE) == 0, ("%s: M_NOFREE set", __func__));
-	if (!(flags & MB_DTOR_SKIP) && (m->m_flags & M_PKTHDR) && !SLIST_EMPTY(&m->m_pkthdr.tags))
+	KASSERT(flags & 0x1, ("%s: obsolete MB_DTOR_SKIP passed", __func__));
+	if ((m->m_flags & M_PKTHDR) && !SLIST_EMPTY(&m->m_pkthdr.tags))
 		m_tag_delete_chain(m, NULL);
 }
 
Index: sys/sys/mbuf.h
===================================================================
--- sys/sys/mbuf.h
+++ sys/sys/mbuf.h
@@ -478,8 +478,6 @@
 #define	M_PROTO10	0x00400000 /* protocol-specific */
 #define	M_PROTO11	0x00800000 /* protocol-specific */
 
-#define MB_DTOR_SKIP	0x1	/* don't pollute the cache by touching a freed mbuf */
-
 /*
  * Flags to purge when crossing layers.
  */