void *
frame_evict() {
ASSERT(lock_held_by_current_thread(&vm_lock));
uint32_t e_ptr = frametable.evict_ptr;
while(1) {
if (frametable.frametable[frametable.evict_ptr].pin == false &&
frametable.frametable[frametable.evict_ptr].pte != (void*) 0xFFFFFFFF) {
struct pagetable_entry* old_pte = frametable.frametable[frametable.evict_ptr].pte;
struct thread *t = thread_from_tid(frametable.frametable[frametable.evict_ptr].tid);
if (old_pte->accessed) {
pagedir_set_accessed(t->pagedir,
pg_no_to_addr(frametable.frametable[frametable.evict_ptr].virt_address), false);
continue;
}
// First we MUST mark the page as not present so that no
// further accesses and modifications of the page content
// are possible
pagedir_set_not_present(t->pagedir,
pg_no_to_addr(frametable.frametable[frametable.evict_ptr].virt_address));
if (old_pte->writable) {
struct spage_table_entry ecmp, *e;
struct hash_elem *elem;
ecmp.vaddr = pg_no_to_addr(frametable.frametable[frametable.evict_ptr].virt_address);
elem = hash_find(&t->sup_pagetable, &ecmp.elem);
if (elem == NULL) {
//swap
struct swaptable_entry * st_e =
create_swaptable_entry(pagenum_to_page(frametable.evict_ptr));
swap_add(st_e);
spage_map_swap(pg_no_to_addr(
frametable.frametable[frametable.evict_ptr].virt_address), st_e, t);
}
else {
e = hash_entry(elem, struct spage_table_entry, elem);
if (e->flags & SPTE_MMAP && old_pte->dirty) {
//flush
spage_flush_mmap(e, pagenum_to_page(frametable.evict_ptr));
//reset dirty bit
pagedir_set_dirty(t->pagedir, e->vaddr, false);
}
else if (!(e->flags & SPTE_MMAP)) {
//file backed writable entry
PANIC("SWAP of page with spage entry!");
}
}
}
frametable.frametable[frametable.evict_ptr].pte = (void*) 0xFFFFFFFF;
void* tmp = pagenum_to_page(frametable.evict_ptr);
log_debug("### Evict page at 0x%08x ###\n", (uint32_t) tmp);
frametable.evict_ptr = (frametable.evict_ptr + 1) % frametable.size;
return tmp;
}
// jump to next position
frametable.evict_ptr = (frametable.evict_ptr + 1) % frametable.size;
if (e_ptr == frametable.evict_ptr)
PANIC("Nothing to evict and nothing swappable");
}
}
int caller(){
int arg1 = 222;
int arg2 = 333;
int sum = swap_add(&arg1, &arg2);
int diff = arg1 - arg2;
return sum*diff;
}
int caller() {
int arg1 = 534;
int arg2 = 1057;
int sum = swap_add(&arg1, &arg2);
int diff = arg1 - arg2;
return sum * diff;
}
