pgtab              49 vm.c             pte_t *pgtab;
pgtab              53 vm.c               pgtab = (pte_t*)p2v(PTE_ADDR(*pde));
pgtab              55 vm.c               if(!alloc || (pgtab = (pte_t*)kalloc()) == 0)
pgtab              58 vm.c               memset(pgtab, 0, PGSIZE);
pgtab              62 vm.c               *pde = v2p(pgtab) | PTE_P | PTE_W | PTE_U;
pgtab              64 vm.c             return &pgtab[PTX(va)];