pgtab              39 vm.c             pte_t *pgtab;
pgtab              43 vm.c               pgtab = (pte_t*)P2V(PTE_ADDR(*pde));
pgtab              45 vm.c               if(!alloc || (pgtab = (pte_t*)kalloc()) == 0)
pgtab              48 vm.c               memset(pgtab, 0, PGSIZE);
pgtab              52 vm.c               *pde = V2P(pgtab) | PTE_P | PTE_W | PTE_U;
pgtab              54 vm.c             return &pgtab[PTX(va)];