uvmdealloc        166 kernel/defs.h  uint64          uvmdealloc(pagetable_t, uint64, uint64);
uvmdealloc        271 kernel/proc.c      sz = uvmdealloc(p->pagetable, sz, sz + n);
uvmdealloc        245 kernel/vm.c          uvmdealloc(pagetable, a, oldsz);
uvmdealloc        251 kernel/vm.c          uvmdealloc(pagetable, a, oldsz);