int
swap_out(struct mm_struct *mm, int n, int in_tick)
{
int i;
for (i = 0; i != n; ++ i)
{
uintptr_t v;
//struct Page **ptr_page=NULL;
struct Page *page;
// cprintf("i %d, SWAP: call swap_out_victim\n",i);
int r = sm->swap_out_victim(mm, &page, in_tick);
if (r != 0) {
cprintf("i %d, swap_out: call swap_out_victim failed\n",i);
break;
}
//assert(!PageReserved(page));
//cprintf("SWAP: choose victim page 0x%08x\n", page);
v=page->pra_vaddr;
pte_t *ptep = get_pte(mm->pgdir, v, 0);
assert((*ptep & PTE_P) != 0);
//Lab3_X: 2013011509
//Only write back if dirty
if (page->need_write_back) {
if (swapfs_write((page->pra_vaddr / PGSIZE + 1) << 8, page) !=
0) {
cprintf("SWAP: failed to save\n");
sm->map_swappable(mm, v, page, 0);
continue;
} else {
cprintf(
"swap_out: i %d, store page in vaddr 0x%x to disk swap "
"entry %d\n",
i, v, page->pra_vaddr / PGSIZE + 1);
*ptep = (page->pra_vaddr / PGSIZE + 1) << 8;
free_page(page);
page->has_backup = 1;
}
} else {
*ptep = (page->pra_vaddr / PGSIZE + 1) << 8;
free_page(page);
}
tlb_invalidate(mm->pgdir, v);
}
return i;
}
// page_launder - try to move page to swap_active_list OR swap_inactive_list,
// - and call swap_fs_write to swap out pages in swap_inactive_list
int
page_launder(void) {
size_t maxscan = nr_inactive_pages, free_count = 0;
list_entry_t *list = &(inactive_list.swap_list), *le = list_next(list);
while (maxscan -- > 0 && le != list) {
struct Page *page = le2page(le, swap_link);
le = list_next(le);
if (!(PageSwap(page) && !PageActive(page))) {
panic("inactive: wrong swap list.\n");
}
swap_list_del(page);
if (page_ref(page) != 0) {
swap_active_list_add(page);
continue ;
}
swap_entry_t entry = page->index;
if (!try_free_swap_entry(entry)) {
if (PageDirty(page)) {
ClearPageDirty(page);
swap_duplicate(entry);
if (swapfs_write(entry, page) != 0) {
SetPageDirty(page);
}
mem_map[swap_offset(entry)] --;
if (page_ref(page) != 0) {
swap_active_list_add(page);
continue ;
}
if (PageDirty(page)) {
swap_inactive_list_add(page);
continue ;
}
try_free_swap_entry(entry);
}
}
free_count ++;
swap_free_page(page);
}
return free_count;
}
