Index: head/sys/arm64/arm64/pmap.c
===================================================================
--- head/sys/arm64/arm64/pmap.c
+++ head/sys/arm64/arm64/pmap.c
@@ -1827,11 +1827,11 @@
 static vm_page_t
 reclaim_pv_chunk(pmap_t locked_pmap, struct rwlock **lockp)
 {
-	struct pch new_tail;
-	struct pv_chunk *pc;
+	struct pv_chunk *pc, *pc_marker, *pc_marker_end;
+	struct pv_chunk_header pc_marker_b, pc_marker_end_b;
 	struct md_page *pvh;
 	pd_entry_t *pde;
-	pmap_t pmap;
+	pmap_t next_pmap, pmap;
 	pt_entry_t *pte, tpte;
 	pv_entry_t pv;
 	vm_offset_t va;
@@ -1839,31 +1839,65 @@
 	struct spglist free;
 	uint64_t inuse;
 	int bit, field, freed, lvl;
+	static int active_reclaims = 0;
 
 	PMAP_LOCK_ASSERT(locked_pmap, MA_OWNED);
 	KASSERT(lockp != NULL, ("reclaim_pv_chunk: lockp is NULL"));
+
 	pmap = NULL;
 	m_pc = NULL;
 	SLIST_INIT(&free);
-	TAILQ_INIT(&new_tail);
+	bzero(&pc_marker_b, sizeof(pc_marker_b));
+	bzero(&pc_marker_end_b, sizeof(pc_marker_end_b));
+	pc_marker = (struct pv_chunk *)&pc_marker_b;
+	pc_marker_end = (struct pv_chunk *)&pc_marker_end_b;
+
 	mtx_lock(&pv_chunks_mutex);
-	while ((pc = TAILQ_FIRST(&pv_chunks)) != NULL && SLIST_EMPTY(&free)) {
-		TAILQ_REMOVE(&pv_chunks, pc, pc_lru);
+	active_reclaims++;
+	TAILQ_INSERT_HEAD(&pv_chunks, pc_marker, pc_lru);
+	TAILQ_INSERT_TAIL(&pv_chunks, pc_marker_end, pc_lru);
+	while ((pc = TAILQ_NEXT(pc_marker, pc_lru)) != pc_marker_end &&
+	    SLIST_EMPTY(&free)) {
+		next_pmap = pc->pc_pmap;
+		if (next_pmap == NULL) {
+			/*
+			 * The next chunk is a marker.  However, it is
+			 * not our marker, so active_reclaims must be
+			 * > 1.  Consequently, the next_chunk code
+			 * will not rotate the pv_chunks list.
+			 */
+			goto next_chunk;
+		}
 		mtx_unlock(&pv_chunks_mutex);
-		if (pmap != pc->pc_pmap) {
+
+		/*
+		 * A pv_chunk can only be removed from the pc_lru list
+		 * when both pv_chunks_mutex is owned and the
+		 * corresponding pmap is locked.
+		 */
+		if (pmap != next_pmap) {
 			if (pmap != NULL && pmap != locked_pmap)
 				PMAP_UNLOCK(pmap);
-			pmap = pc->pc_pmap;
+			pmap = next_pmap;
 			/* Avoid deadlock and lock recursion. */
 			if (pmap > locked_pmap) {
 				RELEASE_PV_LIST_LOCK(lockp);
 				PMAP_LOCK(pmap);
-			} else if (pmap != locked_pmap &&
-			    !PMAP_TRYLOCK(pmap)) {
-				pmap = NULL;
-				TAILQ_INSERT_TAIL(&new_tail, pc, pc_lru);
 				mtx_lock(&pv_chunks_mutex);
 				continue;
+			} else if (pmap != locked_pmap) {
+				if (PMAP_TRYLOCK(pmap)) {
+					mtx_lock(&pv_chunks_mutex);
+					continue;
+				} else {
+					pmap = NULL; /* pmap is not locked */
+					mtx_lock(&pv_chunks_mutex);
+					pc = TAILQ_NEXT(pc_marker, pc_lru);
+					if (pc == NULL ||
+					    pc->pc_pmap != next_pmap)
+						continue;
+					goto next_chunk;
+				}
 			}
 		}
 
@@ -1908,9 +1942,8 @@
 			}
 		}
 		if (freed == 0) {
-			TAILQ_INSERT_TAIL(&new_tail, pc, pc_lru);
 			mtx_lock(&pv_chunks_mutex);
-			continue;
+			goto next_chunk;
 		}
 		/* Every freed mapping is for a 4 KB page. */
 		pmap_resident_count_dec(pmap, freed);
@@ -1927,16 +1960,36 @@
 			m_pc = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((vm_offset_t)pc));
 			dump_drop_page(m_pc->phys_addr);
 			mtx_lock(&pv_chunks_mutex);
+			TAILQ_REMOVE(&pv_chunks, pc, pc_lru);
 			break;
 		}
 		TAILQ_INSERT_HEAD(&pmap->pm_pvchunk, pc, pc_list);
-		TAILQ_INSERT_TAIL(&new_tail, pc, pc_lru);
 		mtx_lock(&pv_chunks_mutex);
 		/* One freed pv entry in locked_pmap is sufficient. */
 		if (pmap == locked_pmap)
 			break;
+
+next_chunk:
+		TAILQ_REMOVE(&pv_chunks, pc_marker, pc_lru);
+		TAILQ_INSERT_AFTER(&pv_chunks, pc, pc_marker, pc_lru);
+		if (active_reclaims == 1 && pmap != NULL) {
+			/*
+			 * Rotate the pv chunks list so that we do not
+			 * scan the same pv chunks that could not be
+			 * freed (because they contained a wired
+			 * and/or superpage mapping) on every
+			 * invocation of reclaim_pv_chunk().
+			 */
+			while ((pc = TAILQ_FIRST(&pv_chunks)) != pc_marker) {
+				MPASS(pc->pc_pmap != NULL);
+				TAILQ_REMOVE(&pv_chunks, pc, pc_lru);
+				TAILQ_INSERT_TAIL(&pv_chunks, pc, pc_lru);
+			}
+		}
 	}
-	TAILQ_CONCAT(&pv_chunks, &new_tail, pc_lru);
+	TAILQ_REMOVE(&pv_chunks, pc_marker, pc_lru);
+	TAILQ_REMOVE(&pv_chunks, pc_marker_end, pc_lru);
+	active_reclaims--;
 	mtx_unlock(&pv_chunks_mutex);
 	if (pmap != NULL && pmap != locked_pmap)
 		PMAP_UNLOCK(pmap);
Index: head/sys/arm64/include/pmap.h
===================================================================
--- head/sys/arm64/include/pmap.h
+++ head/sys/arm64/include/pmap.h
@@ -84,6 +84,7 @@
 	TAILQ_HEAD(,pv_chunk)	pm_pvchunk;	/* list of mappings in pmap */
 	struct vm_radix		pm_root;	/* spare page table pages */
 };
+typedef struct pmap *pmap_t;
 
 typedef struct pv_entry {
 	vm_offset_t		pv_va;	/* virtual address for mapping */
@@ -96,15 +97,20 @@
  */
 #define	_NPCM	3
 #define	_NPCPV	168
-struct pv_chunk {
-	struct pmap *		pc_pmap;
-	TAILQ_ENTRY(pv_chunk)	pc_list;
-	uint64_t		pc_map[_NPCM];  /* bitmap; 1 = free */
+#define	PV_CHUNK_HEADER							\
+	pmap_t			pc_pmap;				\
+	TAILQ_ENTRY(pv_chunk)	pc_list;				\
+	uint64_t		pc_map[_NPCM];	/* bitmap; 1 = free */	\
 	TAILQ_ENTRY(pv_chunk)	pc_lru;
-	struct pv_entry		pc_pventry[_NPCPV];
+
+struct pv_chunk_header {
+	PV_CHUNK_HEADER
 };
 
-typedef struct pmap *pmap_t;
+struct pv_chunk {
+	PV_CHUNK_HEADER
+	struct pv_entry		pc_pventry[_NPCPV];
+};
 
 struct thread;