Dblk
#define nextblk(p, size) ((Dblk) ((char *)(p) + (size)))
void insert(Dblk p, size_t len, Freehdr *tree);
insert(Dblk p, /* Ptr to the block to insert */
insert((Dblk) ptr, nbytes, &kmem_info.free_root);
Dblk p;
p = (Dblk) resalloc(type, nbytes, (caddr_t)0, 0);
Dblk block; /* Ptr to the data block */