CHUNK_OVERHEAD    349 lj_alloc.c     #define MIN_REQUEST		(MIN_CHUNK_SIZE - CHUNK_OVERHEAD - SIZE_T_ONE)
CHUNK_OVERHEAD    353 lj_alloc.c        (((req) + CHUNK_OVERHEAD + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK)
CHUNK_OVERHEAD    404 lj_alloc.c      (is_direct(p)? DIRECT_CHUNK_OVERHEAD : CHUNK_OVERHEAD)
CHUNK_OVERHEAD    448 lj_alloc.c     #define MAX_SMALL_REQUEST  (MAX_SMALL_SIZE - CHUNK_ALIGN_MASK - CHUNK_OVERHEAD)