int core_kickvictim(int *ret)
{
int victim = coremap_get_rr_victim();
int vpn = frame_to_vpn(victim);
struct page_entry *pe;
int result = get_page_entry_victim(&pe, victim);
if(result)
{
return result;
}
//kprintf("%d %x\n", coremap_ptr[victim].pid, coremap_ptr[victim].id);
swap_to_disk(vpn, pe);
*ret = victim;
return 0;
}
void*
frame_evict (void* uaddr)
{
/* 1. Choose a frame to evict, using your page replacement algorithm.
The "accessed" and "dirty" bits in the page table, described below,
will come in handy. */
struct frame_table_entry *fte = NULL;
switch (PAGE_EVICTION_ALGORITHM)
{
/* First in first out */
case PAGE_EVICTION_FIFO:
fte = frame_evict_choose_fifo ();
break;
/* Second chance */
case PAGE_EVICTION_SECONDCHANCE:
fte = frame_evict_choose_secondchance ();
break;
default:
PANIC ("Invalid eviction algorithm choice.");
}
ASSERT (fte != NULL);
/* 2. Remove references to the frame from any page table that refers to it.
Unless you have implemented sharing, only a single page should refer to
a frame at any given time. */
pagedir_clear_page (fte->owner->pagedir, pg_round_down (fte->uaddr));
/* 3. If necessary, write the page to the file system or to swap.
The evicted frame may then be used to store a different page. */
struct page *p_evict =
page_lookup (fte->owner->pages, pg_round_down (fte->uaddr));
if (p_evict == NULL)
PANIC ("Failed to get supp page for existing page.");
/* Page to be evicted is in swap */
if (p_evict->page_location_option == FILESYS)
{
if (p_evict->writable)
{
file_write_at (p_evict->file, fte->kaddr, p_evict->page_read_bytes,
p_evict->ofs);
}
}
else if (p_evict->page_location_option == ALLZERO)
{
// All zero, so can just be overwritten
}
else
{
// From stack
int index = swap_to_disk (pg_round_down (fte->uaddr));
/* Creates a supp page and insert it into pages. */
struct page *p = page_create ();
if (p == NULL)
PANIC ("Failed to get supp page for swap slot.");
p->addr = fte->uaddr;
p->page_location_option = SWAPSLOT;
p->swap_index = index;
page_insert (fte->owner->pages, &p->hash_elem);
}
/* Replace virtual address with new virtual address */
fte->owner = thread_current ();
fte->uaddr = uaddr;
/* Reinsert the frame table entry into the frame table */
lock_acquire (&frame_table_lock);
list_remove (&fte->elem);
list_push_front (&frame_table, &fte->elem);
lock_release (&frame_table_lock);
return fte->kaddr;
}
