diff --git a/include/jemalloc/internal/arena.h b/include/jemalloc/internal/arena.h
index 3d79c627..42086ca1 100644
--- a/include/jemalloc/internal/arena.h
+++ b/include/jemalloc/internal/arena.h
@@ -399,6 +399,7 @@ void	arena_chunk_ralloc_huge_shrink(arena_t *arena, void *chunk,
     size_t oldsize, size_t usize);
 bool	arena_chunk_ralloc_huge_expand(arena_t *arena, void *chunk,
     size_t oldsize, size_t usize, bool *zero);
+void	arena_maybe_purge(arena_t *arena);
 void	arena_purge_all(arena_t *arena);
 void	arena_tcache_fill_small(arena_t *arena, tcache_bin_t *tbin,
     index_t binind, uint64_t prof_accumbytes);
diff --git a/include/jemalloc/internal/chunk.h b/include/jemalloc/internal/chunk.h
index bf6acbd1..1a968a58 100644
--- a/include/jemalloc/internal/chunk.h
+++ b/include/jemalloc/internal/chunk.h
@@ -39,16 +39,21 @@ extern size_t		chunk_npages;
 bool	chunk_register(const void *chunk, const extent_node_t *node);
 void	chunk_deregister(const void *chunk, const extent_node_t *node);
 void	*chunk_alloc_base(size_t size);
-void	*chunk_alloc_arena(chunk_alloc_t *chunk_alloc,
-    chunk_dalloc_t *chunk_dalloc, unsigned arena_ind, void *new_addr,
-    size_t size, size_t alignment, bool *zero);
+void	*chunk_alloc_cache(arena_t *arena, void *new_addr, size_t size,
+    size_t alignment, bool *zero, bool dalloc_node);
 void	*chunk_alloc_default(void *new_addr, size_t size, size_t alignment,
     bool *zero, unsigned arena_ind);
+void	*chunk_alloc_wrapper(arena_t *arena, chunk_alloc_t *chunk_alloc,
+    void *new_addr, size_t size, size_t alignment, bool *zero);
 void	chunk_record(arena_t *arena, extent_tree_t *chunks_szad,
     extent_tree_t *chunks_ad, bool cache, void *chunk, size_t size,
     bool zeroed);
+void	chunk_dalloc_cache(arena_t *arena, void *chunk, size_t size);
+void	chunk_dalloc_arena(arena_t *arena, void *chunk, size_t size,
+    bool zeroed);
 bool	chunk_dalloc_default(void *chunk, size_t size, unsigned arena_ind);
-void	chunk_unmap(arena_t *arena, void *chunk, size_t size, bool zeroed);
+void	chunk_dalloc_wrapper(arena_t *arena, chunk_dalloc_t *chunk_dalloc,
+    void *chunk, size_t size);
 bool	chunk_boot(void);
 void	chunk_prefork(void);
 void	chunk_postfork_parent(void);
diff --git a/include/jemalloc/internal/private_symbols.txt b/include/jemalloc/internal/private_symbols.txt
index dfe62ce5..7c217c74 100644
--- a/include/jemalloc/internal/private_symbols.txt
+++ b/include/jemalloc/internal/private_symbols.txt
@@ -53,6 +53,7 @@ arena_mapbitsp_read
 arena_mapbitsp_write
 arena_maxclass
 arena_maxrun
+arena_maybe_purge
 arena_metadata_allocated_add
 arena_metadata_allocated_get
 arena_metadata_allocated_sub
@@ -124,14 +125,18 @@ bootstrap_free
 bootstrap_malloc
 bt_init
 buferror
-chunk_alloc_arena
+chunk_alloc_cache
 chunk_alloc_base
 chunk_alloc_default
 chunk_alloc_dss
 chunk_alloc_mmap
+chunk_alloc_wrapper
 chunk_boot
+chunk_dalloc_arena
+chunk_dalloc_cache
 chunk_dalloc_default
 chunk_dalloc_mmap
+chunk_dalloc_wrapper
 chunk_deregister
 chunk_dss_boot
 chunk_dss_postfork_child
@@ -147,7 +152,6 @@ chunk_postfork_parent
 chunk_prefork
 chunk_record
 chunk_register
-chunk_unmap
 chunks_rtree
 chunksize
 chunksize_mask
diff --git a/src/arena.c b/src/arena.c
index 762b8182..78aa1ae0 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -20,7 +20,6 @@ unsigned	nhclasses; /* Number of huge size classes. */
  * definition.
  */
 
-static void	arena_chunk_dalloc(arena_t *arena, arena_chunk_t *chunk);
 static void	arena_purge(arena_t *arena, bool all);
 static void	arena_run_dalloc(arena_t *arena, arena_run_t *run, bool dirty,
     bool cleaned);
@@ -427,27 +426,53 @@ arena_chunk_init_spare(arena_t *arena)
 	return (chunk);
 }
 
+static bool
+arena_chunk_register(arena_t *arena, arena_chunk_t *chunk, bool zero)
+{
+
+	extent_node_init(&chunk->node, arena, chunk, chunksize, zero);
+	extent_node_achunk_set(&chunk->node, true);
+	return (chunk_register(chunk, &chunk->node));
+}
+
+static arena_chunk_t *
+arena_chunk_alloc_internal_hard(arena_t *arena, bool *zero)
+{
+	arena_chunk_t *chunk;
+	chunk_alloc_t *chunk_alloc = arena->chunk_alloc;
+	chunk_dalloc_t *chunk_dalloc = arena->chunk_dalloc;
+
+	malloc_mutex_unlock(&arena->lock);
+	chunk = (arena_chunk_t *)chunk_alloc_wrapper(arena, chunk_alloc, NULL,
+	    chunksize, chunksize, zero);
+	if (chunk != NULL && arena_chunk_register(arena, chunk, *zero)) {
+		chunk_dalloc_wrapper(arena, chunk_dalloc, (void *)chunk,
+		    chunksize);
+		chunk = NULL;
+	}
+	malloc_mutex_lock(&arena->lock);
+
+	return (chunk);
+}
+
 static arena_chunk_t *
 arena_chunk_alloc_internal(arena_t *arena, bool *zero)
 {
 	arena_chunk_t *chunk;
-	chunk_alloc_t *chunk_alloc;
-	chunk_dalloc_t *chunk_dalloc;
 
-	chunk_alloc = arena->chunk_alloc;
-	chunk_dalloc = arena->chunk_dalloc;
-	malloc_mutex_unlock(&arena->lock);
-	chunk = (arena_chunk_t *)chunk_alloc_arena(chunk_alloc, chunk_dalloc,
-	    arena->ind, NULL, chunksize, chunksize, zero);
-	if (chunk != NULL) {
-		extent_node_init(&chunk->node, arena, chunk, chunksize, *zero);
-		extent_node_achunk_set(&chunk->node, true);
-		if (chunk_register(chunk, &chunk->node)) {
-			chunk_dalloc((void *)chunk, chunksize, arena->ind);
-			chunk = NULL;
+	if (likely(arena->chunk_alloc == chunk_alloc_default)) {
+		chunk = chunk_alloc_cache(arena, NULL, chunksize, chunksize,
+		    zero, true);
+		if (chunk != NULL && arena_chunk_register(arena, chunk,
+		    *zero)) {
+			chunk_dalloc_cache(arena, chunk, chunksize);
+			return (NULL);
 		}
-	}
-	malloc_mutex_lock(&arena->lock);
+	} else
+		chunk = NULL;
+	if (chunk == NULL)
+		chunk = arena_chunk_alloc_internal_hard(arena, zero);
+
 	if (config_stats && chunk != NULL) {
 		arena->stats.mapped += chunksize;
 		arena->stats.metadata_mapped += (map_bias << LG_PAGE);
@@ -553,11 +578,19 @@ arena_chunk_dalloc(arena_t *arena, arena_chunk_t *chunk)
 			arena_run_dirty_remove(arena, spare, map_bias,
 			    chunk_npages-map_bias);
 		}
-		chunk_dalloc = arena->chunk_dalloc;
-		malloc_mutex_unlock(&arena->lock);
+
 		chunk_deregister(spare, &spare->node);
-		chunk_dalloc((void *)spare, chunksize, arena->ind);
-		malloc_mutex_lock(&arena->lock);
+
+		chunk_dalloc = arena->chunk_dalloc;
+		if (likely(chunk_dalloc == chunk_dalloc_default))
+			chunk_dalloc_cache(arena, (void *)spare, chunksize);
+		else {
+			malloc_mutex_unlock(&arena->lock);
+			chunk_dalloc_wrapper(arena, chunk_dalloc, (void *)spare,
+			    chunksize);
+			malloc_mutex_lock(&arena->lock);
+		}
+
 		if (config_stats) {
 			arena->stats.mapped -= chunksize;
 			arena->stats.metadata_mapped -= (map_bias << LG_PAGE);
@@ -661,28 +694,14 @@ arena_node_dalloc(arena_t *arena, extent_node_t *node)
 	malloc_mutex_unlock(&arena->node_cache_mtx);
 }
 
-void *
-arena_chunk_alloc_huge(arena_t *arena, size_t usize, size_t alignment,
-    bool *zero)
+static void *
+arena_chunk_alloc_huge_hard(arena_t *arena, chunk_alloc_t *chunk_alloc,
+    size_t usize, size_t alignment, bool *zero, size_t csize)
 {
 	void *ret;
-	chunk_alloc_t *chunk_alloc;
-	chunk_dalloc_t *chunk_dalloc;
-	size_t csize = CHUNK_CEILING(usize);
 
-	malloc_mutex_lock(&arena->lock);
-	chunk_alloc = arena->chunk_alloc;
-	chunk_dalloc = arena->chunk_dalloc;
-	if (config_stats) {
-		/* Optimistically update stats prior to unlocking. */
-		arena_huge_malloc_stats_update(arena, usize);
-		arena->stats.mapped += usize;
-	}
-	arena->nactive += (usize >> LG_PAGE);
-	malloc_mutex_unlock(&arena->lock);
-
-	ret = chunk_alloc_arena(chunk_alloc, chunk_dalloc, arena->ind, NULL,
-	    csize, alignment, zero);
+	ret = chunk_alloc_wrapper(arena, chunk_alloc, NULL, csize, alignment,
+	    zero);
 	if (ret == NULL) {
 		/* Revert optimistic stats updates. */
 		malloc_mutex_lock(&arena->lock);
@@ -692,12 +711,42 @@ arena_chunk_alloc_huge(arena_t *arena, size_t usize, size_t alignment,
 		}
 		arena->nactive -= (usize >> LG_PAGE);
 		malloc_mutex_unlock(&arena->lock);
-		return (NULL);
 	}
 
-	if (config_stats)
-		stats_cactive_add(usize);
+	return (ret);
+}
 
+void *
+arena_chunk_alloc_huge(arena_t *arena, size_t usize, size_t alignment,
+    bool *zero)
+{
+	void *ret;
+	chunk_alloc_t *chunk_alloc;
+	size_t csize = CHUNK_CEILING(usize);
+
+	malloc_mutex_lock(&arena->lock);
+
+	/* Optimistically update stats. */
+	if (config_stats) {
+		arena_huge_malloc_stats_update(arena, usize);
+		arena->stats.mapped += usize;
+	}
+	arena->nactive += (usize >> LG_PAGE);
+
+	chunk_alloc = arena->chunk_alloc;
+	if (likely(chunk_alloc == chunk_alloc_default)) {
+		ret = chunk_alloc_cache(arena, NULL, csize, alignment, zero,
+		    true);
+	} else
+		ret = NULL;
+	malloc_mutex_unlock(&arena->lock);
+	if (ret == NULL) {
+		ret = arena_chunk_alloc_huge_hard(arena, chunk_alloc, usize,
+		    alignment, zero, csize);
+	}
+
+	if (config_stats && ret != NULL)
+		stats_cactive_add(usize);
 	return (ret);
 }
 
@@ -705,7 +754,9 @@ void
 arena_chunk_dalloc_huge(arena_t *arena, void *chunk, size_t usize)
 {
 	chunk_dalloc_t *chunk_dalloc;
+	size_t csize;
 
+	csize = CHUNK_CEILING(usize);
 	malloc_mutex_lock(&arena->lock);
 	chunk_dalloc = arena->chunk_dalloc;
 	if (config_stats) {
@@ -714,8 +765,14 @@ arena_chunk_dalloc_huge(arena_t *arena, void *chunk, size_t usize)
 		stats_cactive_sub(usize);
 	}
 	arena->nactive -= (usize >> LG_PAGE);
-	malloc_mutex_unlock(&arena->lock);
-	chunk_dalloc(chunk, CHUNK_CEILING(usize), arena->ind);
+
+	if (likely(chunk_dalloc == chunk_dalloc_default)) {
+		chunk_dalloc_cache(arena, chunk, csize);
+		malloc_mutex_unlock(&arena->lock);
+	} else {
+		malloc_mutex_unlock(&arena->lock);
+		chunk_dalloc_wrapper(arena, chunk_dalloc, chunk, csize);
+	}
 }
 
 void
@@ -747,12 +804,10 @@ void
 arena_chunk_ralloc_huge_shrink(arena_t *arena, void *chunk, size_t oldsize,
     size_t usize)
 {
-	chunk_dalloc_t *chunk_dalloc;
 	size_t udiff = oldsize - usize;
 	size_t cdiff = CHUNK_CEILING(oldsize) - CHUNK_CEILING(usize);
 
 	malloc_mutex_lock(&arena->lock);
-	chunk_dalloc = arena->chunk_dalloc;
 	if (config_stats) {
 		arena_huge_ralloc_stats_update(arena, oldsize, usize);
 		if (cdiff != 0) {
@@ -761,52 +816,81 @@ arena_chunk_ralloc_huge_shrink(arena_t *arena, void *chunk, size_t oldsize,
 		}
 	}
 	arena->nactive -= udiff >> LG_PAGE;
-	malloc_mutex_unlock(&arena->lock);
+
 	if (cdiff != 0) {
-		chunk_dalloc((void *)((uintptr_t)chunk + CHUNK_CEILING(usize)),
-		    cdiff, arena->ind);
+		chunk_dalloc_t *chunk_dalloc = arena->chunk_dalloc;
+		void *nchunk = (void *)((uintptr_t)chunk +
+		    CHUNK_CEILING(usize));
+
+		if (likely(chunk_dalloc == chunk_dalloc_default)) {
+			chunk_dalloc_cache(arena, nchunk, cdiff);
+			malloc_mutex_unlock(&arena->lock);
+		} else {
+			malloc_mutex_unlock(&arena->lock);
+			chunk_dalloc_wrapper(arena, chunk_dalloc, nchunk,
+			    cdiff);
+		}
+	} else
+		malloc_mutex_unlock(&arena->lock);
+}
+
+bool
+arena_chunk_ralloc_huge_expand_hard(arena_t *arena, chunk_alloc_t *chunk_alloc,
+    size_t oldsize, size_t usize, bool *zero, void *nchunk, size_t udiff,
+    size_t cdiff)
+{
+	bool err;
+
+	err = (chunk_alloc_wrapper(arena, chunk_alloc, nchunk, cdiff, chunksize,
+	    zero) == NULL);
+	if (err) {
+		/* Revert optimistic stats updates. */
+		malloc_mutex_lock(&arena->lock);
+		if (config_stats) {
+			arena_huge_ralloc_stats_update_undo(arena, oldsize,
+			    usize);
+			arena->stats.mapped -= cdiff;
+		}
+		arena->nactive -= (udiff >> LG_PAGE);
+		malloc_mutex_unlock(&arena->lock);
 	}
+	return (err);
 }
 
 bool
 arena_chunk_ralloc_huge_expand(arena_t *arena, void *chunk, size_t oldsize,
     size_t usize, bool *zero)
 {
+	bool err;
 	chunk_alloc_t *chunk_alloc;
-	chunk_dalloc_t *chunk_dalloc;
+	void *nchunk = (void *)((uintptr_t)chunk + CHUNK_CEILING(oldsize));
 	size_t udiff = usize - oldsize;
 	size_t cdiff = CHUNK_CEILING(usize) - CHUNK_CEILING(oldsize);
 
 	malloc_mutex_lock(&arena->lock);
-	chunk_alloc = arena->chunk_alloc;
-	chunk_dalloc = arena->chunk_dalloc;
+
+	/* Optimistically update stats. */
 	if (config_stats) {
-		/* Optimistically update stats prior to unlocking. */
 		arena_huge_ralloc_stats_update(arena, oldsize, usize);
 		arena->stats.mapped += cdiff;
 	}
 	arena->nactive += (udiff >> LG_PAGE);
-	malloc_mutex_unlock(&arena->lock);
 
-	if (chunk_alloc_arena(chunk_alloc, chunk_dalloc, arena->ind,
-	    (void *)((uintptr_t)chunk + CHUNK_CEILING(oldsize)), cdiff,
-	    chunksize, zero) == NULL) {
-		/* Revert optimistic stats updates. */
-		malloc_mutex_lock(&arena->lock);
-		if (config_stats) {
-			arena_huge_ralloc_stats_update_undo(arena,
-			    oldsize, usize);
-			arena->stats.mapped -= cdiff;
-		}
-		arena->nactive -= (udiff >> LG_PAGE);
-		malloc_mutex_unlock(&arena->lock);
-		return (true);
+	chunk_alloc = arena->chunk_alloc;
+	if (likely(chunk_alloc == chunk_alloc_default)) {
+		err = (chunk_alloc_cache(arena, nchunk, cdiff, chunksize, zero,
+		    true) == NULL);
+	} else
+		err = true;
+	malloc_mutex_unlock(&arena->lock);
+	if (err) {
+		err = arena_chunk_ralloc_huge_expand_hard(arena, chunk_alloc,
+		    oldsize, usize, zero, nchunk, udiff, cdiff);
 	}
 
-	if (config_stats)
+	if (config_stats && !err)
 		stats_cactive_add(udiff);
-
-	return (false);
+	return (err);
 }
 
 static arena_run_t *
@@ -909,7 +993,7 @@ arena_run_alloc_small(arena_t *arena, size_t size, index_t binind)
 	return (arena_run_alloc_small_helper(arena, size, binind));
 }
 
-JEMALLOC_INLINE_C void
+void
 arena_maybe_purge(arena_t *arena)
 {
 	size_t threshold;
@@ -999,39 +1083,25 @@ arena_stash_dirty(arena_t *arena, bool all, size_t npurge,
 		runselm_next = qr_next(runselm, rd_link);
 
 		if (runselm == &chunkselm->runs_dirty) {
-			extent_node_t *chunkselm_next, *tnode;
-			void *addr;
-			size_t size;
-			bool zeroed, zero;
+			extent_node_t *chunkselm_next;
+			bool zero;
 			UNUSED void *chunk;
 
 			chunkselm_next = qr_next(chunkselm, cc_link);
 			/*
-			 * Cache contents of chunkselm prior to it being
-			 * destroyed as a side effect of allocating the chunk.
+			 * Allocate.  chunkselm remains valid due to the
+			 * dalloc_node=false argument to chunk_alloc_cache().
 			 */
-			addr = extent_node_addr_get(chunkselm);
-			size = extent_node_size_get(chunkselm);
-			zeroed = extent_node_zeroed_get(chunkselm);
-			/* Allocate. */
 			zero = false;
-			chunk = arena->chunk_alloc(addr, size, chunksize, &zero,
-			    arena->ind);
-			assert(chunk == addr);
-			assert(zero == zeroed);
-			/*
-			 * Create a temporary node to link into the ring of
-			 * stashed allocations.  OOM shouldn't be possible
-			 * because chunk allocation just cached a node.
-			 */
-			tnode = arena_node_alloc(arena);
-			assert(tnode != NULL);
-			/* Stash. */
-			extent_node_init(tnode, arena, addr, size, zeroed);
-			extent_node_dirty_linkage_init(tnode);
-			extent_node_dirty_insert(tnode, purge_runs_sentinel,
+			chunk = chunk_alloc_cache(arena,
+			    extent_node_addr_get(chunkselm),
+			    extent_node_size_get(chunkselm), chunksize, &zero,
+			    false);
+			assert(chunk == extent_node_addr_get(chunkselm));
+			assert(zero == extent_node_zeroed_get(chunkselm));
+			extent_node_dirty_insert(chunkselm, purge_runs_sentinel,
 			    purge_chunks_sentinel);
-			npages = size >> LG_PAGE;
+			npages = extent_node_size_get(chunkselm) >> LG_PAGE;
 			chunkselm = chunkselm_next;
 		} else {
 			arena_chunk_t *chunk =
@@ -1170,7 +1240,7 @@ arena_unstash_purged(arena_t *arena,
 			extent_node_dirty_remove(chunkselm);
 			arena_node_dalloc(arena, chunkselm);
 			chunkselm = chunkselm_next;
-			chunk_unmap(arena, addr, size, zeroed);
+			chunk_dalloc_arena(arena, addr, size, zeroed);
 		} else {
 			arena_run_t *run = &runselm->run;
 			qr_remove(runselm, rd_link);
diff --git a/src/chunk.c b/src/chunk.c
index 264e4f27..08f21f6a 100644
--- a/src/chunk.c
+++ b/src/chunk.c
@@ -65,7 +65,7 @@ chunk_deregister(const void *chunk, const extent_node_t *node)
 static void *
 chunk_recycle(arena_t *arena, extent_tree_t *chunks_szad,
     extent_tree_t *chunks_ad, bool cache, void *new_addr, size_t size,
-    size_t alignment, bool *zero)
+    size_t alignment, bool *zero, bool dalloc_node)
 {
 	void *ret;
 	extent_node_t *node;
@@ -74,6 +74,7 @@ chunk_recycle(arena_t *arena, extent_tree_t *chunks_szad,
 	bool zeroed;
 
 	assert(new_addr == NULL || alignment == chunksize);
+	assert(dalloc_node || new_addr != NULL);
 
 	alloc_size = size + alignment - chunksize;
 	/* Beware size_t wrap-around. */
@@ -129,7 +130,8 @@ chunk_recycle(arena_t *arena, extent_tree_t *chunks_szad,
 	}
 	malloc_mutex_unlock(&arena->chunks_mtx);
 
-	if (node != NULL)
+	assert(!dalloc_node || node != NULL);
+	if (dalloc_node && node != NULL)
 		arena_node_dalloc(arena, node);
 	if (*zero) {
 		if (!zeroed)
@@ -153,8 +155,8 @@ chunk_alloc_core_dss(arena_t *arena, void *new_addr, size_t size,
 	void *ret;
 
 	if ((ret = chunk_recycle(arena, &arena->chunks_szad_dss,
-	    &arena->chunks_ad_dss, false, new_addr, size, alignment, zero)) !=
-	    NULL)
+	    &arena->chunks_ad_dss, false, new_addr, size, alignment, zero,
+	    true)) != NULL)
 		return (ret);
 	ret = chunk_alloc_dss(arena, new_addr, size, alignment, zero);
 	return (ret);
@@ -177,11 +179,6 @@ chunk_alloc_core(arena_t *arena, void *new_addr, size_t size, size_t alignment,
 	assert(alignment != 0);
 	assert((alignment & chunksize_mask) == 0);
 
-	/* cache. */
-	if ((ret = chunk_recycle(arena, &arena->chunks_szad_cache,
-	    &arena->chunks_ad_cache, true, new_addr, size, alignment, zero)) !=
-	    NULL)
-		return (ret);
 	/* "primary" dss. */
 	if (have_dss && dss_prec == dss_prec_primary && (ret =
 	    chunk_alloc_core_dss(arena, new_addr, size, alignment, zero)) !=
@@ -190,7 +187,7 @@ chunk_alloc_core(arena_t *arena, void *new_addr, size_t size, size_t alignment,
 	/* mmap. */
 	if (!config_munmap && (ret = chunk_recycle(arena,
 	    &arena->chunks_szad_mmap, &arena->chunks_ad_mmap, false, new_addr,
-	    size, alignment, zero)) != NULL)
+	    size, alignment, zero, true)) != NULL)
 		return (ret);
 	/*
 	 * Requesting an address is not implemented for chunk_alloc_mmap(), so
@@ -231,19 +228,18 @@ chunk_alloc_base(size_t size)
 }
 
 void *
-chunk_alloc_arena(chunk_alloc_t *chunk_alloc, chunk_dalloc_t *chunk_dalloc,
-    unsigned arena_ind, void *new_addr, size_t size, size_t alignment,
-    bool *zero)
+chunk_alloc_cache(arena_t *arena, void *new_addr, size_t size, size_t alignment,
+    bool *zero, bool dalloc_node)
 {
-	void *ret;
 
-	ret = chunk_alloc(new_addr, size, alignment, zero, arena_ind);
-	if (ret == NULL)
-		return (NULL);
-	if (config_valgrind)
-		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, size);
+	assert(size != 0);
+	assert((size & chunksize_mask) == 0);
+	assert(alignment != 0);
+	assert((alignment & chunksize_mask) == 0);
 
-	return (ret);
+	return (chunk_recycle(arena, &arena->chunks_szad_cache,
+	    &arena->chunks_ad_cache, true, new_addr, size, alignment, zero,
+	    dalloc_node));
 }
 
 static arena_t *
@@ -262,7 +258,27 @@ chunk_arena_get(unsigned arena_ind)
 	return (arena);
 }
 
-/* Default arena chunk allocation routine in the absence of user override. */
+static void *
+chunk_alloc_arena(arena_t *arena, void *new_addr, size_t size, size_t alignment,
+    bool *zero)
+{
+	void *ret;
+
+	ret = chunk_alloc_core(arena, new_addr, size, alignment, zero,
+	    arena->dss_prec);
+	if (ret == NULL)
+		return (NULL);
+	if (config_valgrind)
+		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, size);
+
+	return (ret);
+}
+
+/*
+ * Default arena chunk allocation routine in the absence of user override.  This
+ * function isn't actually used by jemalloc, but it does the right thing if the
+ * application passes calls through to it during chunk allocation.
+ */
 void *
 chunk_alloc_default(void *new_addr, size_t size, size_t alignment, bool *zero,
     unsigned arena_ind)
@@ -270,8 +286,21 @@ chunk_alloc_default(void *new_addr, size_t size, size_t alignment, bool *zero,
 	arena_t *arena;
 
 	arena = chunk_arena_get(arena_ind);
-	return (chunk_alloc_core(arena, new_addr, size, alignment, zero,
-	    arena->dss_prec));
+	return (chunk_alloc_arena(arena, new_addr, size, alignment, zero));
+}
+
+void *
+chunk_alloc_wrapper(arena_t *arena, chunk_alloc_t *chunk_alloc, void *new_addr,
+    size_t size, size_t alignment, bool *zero)
+{
+	void *ret;
+
+	ret = chunk_alloc(new_addr, size, alignment, zero, arena->ind);
+	if (ret == NULL)
+		return (NULL);
+	if (config_valgrind && chunk_alloc != chunk_alloc_default)
+		JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(chunk, chunksize);
+	return (ret);
 }
 
 void
@@ -355,8 +384,8 @@ label_return:
 	malloc_mutex_unlock(&arena->chunks_mtx);
 }
 
-static void
-chunk_cache(arena_t *arena, void *chunk, size_t size)
+void
+chunk_dalloc_cache(arena_t *arena, void *chunk, size_t size)
 {
 
 	assert(chunk != NULL);
@@ -366,19 +395,11 @@ chunk_cache(arena_t *arena, void *chunk, size_t size)
 
 	chunk_record(arena, &arena->chunks_szad_cache, &arena->chunks_ad_cache,
 	    true, chunk, size, false);
-}
-
-/* Default arena chunk deallocation routine in the absence of user override. */
-bool
-chunk_dalloc_default(void *chunk, size_t size, unsigned arena_ind)
-{
-
-	chunk_cache(chunk_arena_get(arena_ind), chunk, size);
-	return (false);
+	arena_maybe_purge(arena);
 }
 
 void
-chunk_unmap(arena_t *arena, void *chunk, size_t size, bool zeroed)
+chunk_dalloc_arena(arena_t *arena, void *chunk, size_t size, bool zeroed)
 {
 
 	assert(chunk != NULL);
@@ -395,6 +416,29 @@ chunk_unmap(arena_t *arena, void *chunk, size_t size, bool zeroed)
 	}
 }
 
+/*
+ * Default arena chunk deallocation routine in the absence of user override.
+ * This function isn't actually used by jemalloc, but it does the right thing if
+ * the application passes calls through to it during chunk deallocation.
+ */
+bool
+chunk_dalloc_default(void *chunk, size_t size, unsigned arena_ind)
+{
+
+	chunk_dalloc_arena(chunk_arena_get(arena_ind), chunk, size, false);
+	return (false);
+}
+
+void
+chunk_dalloc_wrapper(arena_t *arena, chunk_dalloc_t *chunk_dalloc, void *chunk,
+    size_t size)
+{
+
+	chunk_dalloc(chunk, size, arena->ind);
+	if (config_valgrind && chunk_dalloc != chunk_dalloc_default)
+		JEMALLOC_VALGRIND_MAKE_MEM_NOACCESS(chunk, size);
+}
+
 static rtree_node_elm_t *
 chunks_rtree_node_alloc(size_t nelms)
 {