--- libmalloc/libmalloc-474.0.13/src/magazine_zone.h
+++ libmalloc/libmalloc-283.100.5/src/magazine_zone.h
@@ -132,11 +132,6 @@
  * their size in the block, and store it both after the 'next' pointer, and in
  * the last 2 bytes of the block.
  *
- * With zero-on-free, free blocks of two or more quanta are zeroed out after
- * their leading inline metadata.  This invariant is maintained when blocks are
- * split and coalesced, enabling calloc(3) to return free blocks as-is after
- * clearing the metadata.
- *
  * 1-quantum block
  * Offset (32-bit mode)	(64-bit mode)
  * 0x0          0x0      : previous
@@ -148,7 +143,6 @@
  * 0x0          0x0      : previous
  * 0x4          0x08     : next
  * 0x8          0x10     : size (in quantum counts)
- * 0xa          0x12     : start of zeroed body
  * end - 2      end - 2  : size (in quantum counts)
  * end          end
  *
@@ -231,11 +225,6 @@
 } region_free_blocks_t;
 
 typedef uint32_t region_cookie_t;
-
-OS_ENUM(rack_dispose_flags, uint32_t,
-	RACK_DISPOSE_DELAY = 0x1,
-	RACK_DISPOSE_NEEDED = 0x2,
-);
 
 typedef struct region_trailer {
 	struct region_trailer *prev;
@@ -245,8 +234,6 @@
 	mag_index_t mag_index;
 	volatile int32_t pinned_to_depot;
 	bool recirc_suitable;
-	// Locking: dispose_flags must be locked under the rack's region lock
-	rack_dispose_flags_t dispose_flags;
 } region_trailer_t;
 
 typedef struct tiny_region {
@@ -736,11 +723,7 @@
 typedef struct large_entry_s {
 	vm_address_t address;
 	vm_size_t size;
-#if CONFIG_DEFERRED_RECLAIM
-	uint64_t reclaim_index;
-#else
 	boolean_t did_madvise_reusable;
-#endif /* CONFIG_DEFERRED_RECLAIM */
 } large_entry_t;
 
 #if !CONFIG_LARGE_CACHE && DEBUG_MALLOC