Arena chunk decommit cleanups and fixes.

Decommit arena chunk header during chunk deallocation if the rest of the
chunk is decommitted.

include/jemalloc/internal/arena.h

@@ -838,6 +838,7 @@ arena_mapbits_unzeroed_set(arena_chunk_t *chunk, size_t pageind,
 	size_t *mapbitsp = arena_mapbitsp_get(chunk, pageind);
 	size_t mapbits = arena_mapbitsp_read(mapbitsp);
 
+	assert((mapbits & CHUNK_MAP_DECOMMITTED) == 0 || !unzeroed);
 	arena_mapbitsp_write(mapbitsp, (mapbits & ~CHUNK_MAP_UNZEROED) |
 	    unzeroed);
 }

include/jemalloc/internal/chunk.h

@@ -61,7 +61,7 @@ void	*chunk_alloc_cache(arena_t *arena, chunk_hooks_t *chunk_hooks,
 void	*chunk_alloc_wrapper(arena_t *arena, chunk_hooks_t *chunk_hooks,
     void *new_addr, size_t size, size_t alignment, bool *zero, bool *commit);
 void	chunk_dalloc_cache(arena_t *arena, chunk_hooks_t *chunk_hooks,
-    void *chunk, size_t size);
+    void *chunk, size_t size, bool committed);
 void	chunk_dalloc_arena(arena_t *arena, chunk_hooks_t *chunk_hooks,
     void *chunk, size_t size, bool zeroed, bool committed);
 void	chunk_dalloc_wrapper(arena_t *arena, chunk_hooks_t *chunk_hooks,

include/jemalloc/internal/extent.h

@@ -27,7 +27,7 @@ struct extent_node_s {
 	/*
 	 * True if physical memory is committed to the extent, whether
 	 * explicitly or implicitly as on a system that overcommits and
-	 * satisfies physical mamory needs on demand via soft page faults.
+	 * satisfies physical memory needs on demand via soft page faults.
 	 */
 	bool			en_committed;
 
@@ -125,6 +125,7 @@ JEMALLOC_INLINE bool
 extent_node_committed_get(const extent_node_t *node)
 {
 
+	assert(!extent_node_achunk_get(node));
 	return (node->en_committed);
 }