diff --git a/include/jemalloc/internal/extent.h b/include/jemalloc/internal/extent.h
index acc67f00..33f5932c 100644
--- a/include/jemalloc/internal/extent.h
+++ b/include/jemalloc/internal/extent.h
@@ -18,6 +18,9 @@ struct extent_s {
 	/* Total region size. */
 	size_t			e_size;
 
+	/* True if extent is active (in use). */
+	bool			e_active;
+
 	/*
 	 * The zeroed flag is used by chunk recycling code to track whether
 	 * memory is zero-filled.
@@ -73,6 +76,7 @@ rb_proto(, extent_tree_ad_, extent_tree_t, extent_t)
 arena_t	*extent_arena_get(const extent_t *extent);
 void	*extent_addr_get(const extent_t *extent);
 size_t	extent_size_get(const extent_t *extent);
+bool	extent_active_get(const extent_t *extent);
 bool	extent_zeroed_get(const extent_t *extent);
 bool	extent_committed_get(const extent_t *extent);
 bool	extent_achunk_get(const extent_t *extent);
@@ -80,13 +84,13 @@ prof_tctx_t	*extent_prof_tctx_get(const extent_t *extent);
 void	extent_arena_set(extent_t *extent, arena_t *arena);
 void	extent_addr_set(extent_t *extent, void *addr);
 void	extent_size_set(extent_t *extent, size_t size);
+void	extent_active_set(extent_t *extent, bool active);
 void	extent_zeroed_set(extent_t *extent, bool zeroed);
 void	extent_committed_set(extent_t *extent, bool committed);
 void	extent_achunk_set(extent_t *extent, bool achunk);
 void	extent_prof_tctx_set(extent_t *extent, prof_tctx_t *tctx);
 void	extent_init(extent_t *extent, arena_t *arena, void *addr,
-    size_t size, bool zeroed, bool committed);
-void	extent_dirty_linkage_init(extent_t *extent);
+    size_t size, bool active, bool zeroed, bool committed);
 void	extent_dirty_insert(extent_t *extent,
     arena_runs_dirty_link_t *runs_dirty, extent_t *chunks_dirty);
 void	extent_dirty_remove(extent_t *extent);
@@ -114,6 +118,13 @@ extent_size_get(const extent_t *extent)
 	return (extent->e_size);
 }
 
+JEMALLOC_INLINE bool
+extent_active_get(const extent_t *extent)
+{
+
+	return (extent->e_active);
+}
+
 JEMALLOC_INLINE bool
 extent_zeroed_get(const extent_t *extent)
 {
@@ -164,6 +175,13 @@ extent_size_set(extent_t *extent, size_t size)
 	extent->e_size = size;
 }
 
+JEMALLOC_INLINE void
+extent_active_set(extent_t *extent, bool active)
+{
+
+	extent->e_active = active;
+}
+
 JEMALLOC_INLINE void
 extent_zeroed_set(extent_t *extent, bool zeroed)
 {
@@ -194,23 +212,18 @@ extent_prof_tctx_set(extent_t *extent, prof_tctx_t *tctx)
 
 JEMALLOC_INLINE void
 extent_init(extent_t *extent, arena_t *arena, void *addr, size_t size,
-    bool zeroed, bool committed)
+    bool active, bool zeroed, bool committed)
 {
 
 	extent_arena_set(extent, arena);
 	extent_addr_set(extent, addr);
 	extent_size_set(extent, size);
+	extent_active_set(extent, active);
 	extent_zeroed_set(extent, zeroed);
 	extent_committed_set(extent, committed);
 	extent_achunk_set(extent, false);
 	if (config_prof)
 		extent_prof_tctx_set(extent, NULL);
-}
-
-JEMALLOC_INLINE void
-extent_dirty_linkage_init(extent_t *extent)
-{
-
 	qr_new(&extent->rd, rd_link);
 	qr_new(extent, cc_link);
 }
diff --git a/include/jemalloc/internal/jemalloc_internal.h.in b/include/jemalloc/internal/jemalloc_internal.h.in
index c7d97371..a7f07818 100644
--- a/include/jemalloc/internal/jemalloc_internal.h.in
+++ b/include/jemalloc/internal/jemalloc_internal.h.in
@@ -1093,6 +1093,7 @@ ivsalloc(tsdn_t *tsdn, const void *ptr, bool demote)
 	extent = chunk_lookup(tsdn, ptr, false);
 	if (extent == NULL)
 		return (0);
+	assert(extent_active_get(extent));
 	/* Only arena chunks should be looked up via interior pointers. */
 	assert(extent_addr_get(extent) == ptr ||
 	    extent_achunk_get(extent));
diff --git a/include/jemalloc/internal/private_symbols.txt b/include/jemalloc/internal/private_symbols.txt
index 102f01c0..19402462 100644
--- a/include/jemalloc/internal/private_symbols.txt
+++ b/include/jemalloc/internal/private_symbols.txt
@@ -207,6 +207,8 @@ decay_ticker_get
 dss_prec_names
 extent_achunk_get
 extent_achunk_set
+extent_active_get
+extent_active_set
 extent_addr_get
 extent_addr_set
 extent_arena_get
@@ -214,7 +216,6 @@ extent_arena_set
 extent_committed_get
 extent_committed_set
 extent_dirty_insert
-extent_dirty_linkage_init
 extent_dirty_remove
 extent_init
 extent_prof_tctx_get
diff --git a/src/arena.c b/src/arena.c
index 8a93fca0..5a4605d0 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -225,7 +225,6 @@ arena_chunk_cache_maybe_insert(arena_t *arena, extent_t *extent, bool cache)
 {
 
 	if (cache) {
-		extent_dirty_linkage_init(extent);
 		extent_dirty_insert(extent, &arena->runs_dirty,
 		    &arena->chunks_cache);
 		arena->ndirty += arena_chunk_dirty_npages(extent);
@@ -526,7 +525,7 @@ arena_chunk_register(tsdn_t *tsdn, arena_t *arena, arena_chunk_t *chunk,
 	 * runs is tracked individually, and upon chunk deallocation the entire
 	 * chunk is in a consistent commit state.
 	 */
-	extent_init(&chunk->extent, arena, chunk, chunksize, zero, true);
+	extent_init(&chunk->extent, arena, chunk, chunksize, true, zero, true);
 	extent_achunk_set(&chunk->extent, true);
 	return (chunk_register(tsdn, chunk, &chunk->extent));
 }
@@ -1723,7 +1722,8 @@ arena_purge_to_limit(tsdn_t *tsdn, arena_t *arena, size_t ndirty_limit)
 	    arena->lg_dirty_mult) < arena->ndirty || ndirty_limit == 0);
 
 	qr_new(&purge_runs_sentinel, rd_link);
-	extent_dirty_linkage_init(&purge_chunks_sentinel);
+	extent_init(&purge_chunks_sentinel, arena, NULL, 0, false, false,
+	    false);
 
 	npurge = arena_stash_dirty(tsdn, arena, &chunk_hooks, ndirty_limit,
 	    &purge_runs_sentinel, &purge_chunks_sentinel);
diff --git a/src/base.c b/src/base.c
index a9ab279e..0176fb80 100644
--- a/src/base.c
+++ b/src/base.c
@@ -66,7 +66,7 @@ base_chunk_alloc(tsdn_t *tsdn, size_t minsize)
 			base_resident += PAGE_CEILING(nsize);
 		}
 	}
-	extent_init(extent, NULL, addr, csize, true, true);
+	extent_init(extent, NULL, addr, csize, true, true, true);
 	return (extent);
 }
 
@@ -90,7 +90,7 @@ base_alloc(tsdn_t *tsdn, size_t size)
 	csize = CACHELINE_CEILING(size);
 
 	usize = s2u(csize);
-	extent_init(&key, NULL, NULL, usize, false, false);
+	extent_init(&key, NULL, NULL, usize, false, false, false);
 	malloc_mutex_lock(tsdn, &base_mtx);
 	extent = extent_tree_szad_nsearch(&base_avail_szad, &key);
 	if (extent != NULL) {
diff --git a/src/chunk.c b/src/chunk.c
index beef41fe..055b4fcb 100644
--- a/src/chunk.c
+++ b/src/chunk.c
@@ -239,7 +239,7 @@ chunk_first_best_fit(arena_t *arena, extent_tree_t *chunks_szad,
 
 	assert(size == CHUNK_CEILING(size));
 
-	extent_init(&key, arena, NULL, size, false, false);
+	extent_init(&key, arena, NULL, size, false, false, false);
 	return (extent_tree_szad_nsearch(chunks_szad, &key));
 }
 
@@ -270,7 +270,8 @@ chunk_recycle(tsdn_t *tsdn, arena_t *arena, chunk_hooks_t *chunk_hooks,
 	chunk_hooks_assure_initialized_locked(tsdn, arena, chunk_hooks);
 	if (new_addr != NULL) {
 		extent_t key;
-		extent_init(&key, arena, new_addr, alloc_size, false, false);
+		extent_init(&key, arena, new_addr, alloc_size, false, false,
+		    false);
 		extent = extent_tree_ad_search(chunks_ad, &key);
 	} else {
 		extent = chunk_first_best_fit(arena, chunks_szad, chunks_ad,
@@ -336,7 +337,7 @@ chunk_recycle(tsdn_t *tsdn, arena_t *arena, chunk_hooks_t *chunk_hooks,
 			}
 		}
 		extent_init(extent, arena, (void *)((uintptr_t)(ret) + size),
-		    trailsize, zeroed, committed);
+		    trailsize, false, zeroed, committed);
 		extent_tree_szad_insert(chunks_szad, extent);
 		extent_tree_ad_insert(chunks_ad, extent);
 		arena_chunk_cache_maybe_insert(arena, extent, cache);
@@ -534,7 +535,7 @@ chunk_record(tsdn_t *tsdn, arena_t *arena, chunk_hooks_t *chunk_hooks,
 	malloc_mutex_lock(tsdn, &arena->chunks_mtx);
 	chunk_hooks_assure_initialized_locked(tsdn, arena, chunk_hooks);
 	extent_init(&key, arena, (void *)((uintptr_t)chunk + size), 0, false,
-	    false);
+	    false, false);
 	extent = extent_tree_ad_nsearch(chunks_ad, &key);
 	/* Try to coalesce forward. */
 	if (extent != NULL && extent_addr_get(extent) == extent_addr_get(&key)
@@ -570,7 +571,7 @@ chunk_record(tsdn_t *tsdn, arena_t *arena, chunk_hooks_t *chunk_hooks,
 			}
 			goto label_return;
 		}
-		extent_init(extent, arena, chunk, size, !unzeroed,
+		extent_init(extent, arena, chunk, size, false, !unzeroed,
 		    committed);
 		extent_tree_ad_insert(chunks_ad, extent);
 		extent_tree_szad_insert(chunks_szad, extent);
diff --git a/src/huge.c b/src/huge.c
index 0b91c369..b6ad4ba6 100644
--- a/src/huge.c
+++ b/src/huge.c
@@ -50,7 +50,7 @@ huge_palloc(tsdn_t *tsdn, arena_t *arena, size_t usize, size_t alignment,
 		return (NULL);
 	}
 
-	extent_init(extent, arena, ret, usize, is_zeroed, true);
+	extent_init(extent, arena, ret, usize, true, is_zeroed, true);
 
 	if (chunk_register(tsdn, ret, extent)) {
 		arena_chunk_dalloc_huge(tsdn, arena, ret, usize);