/*
* Returns remaining count of pages to be swapped out by followup call.
*/
static inline int swap_out_mm(struct mm_struct * mm, int count, int * mmcounter, zone_t * classzone)
{
unsigned long address;
struct vm_area_struct* vma;
/*
* Find the proper vm-area after freezing the vma chain
* and ptes.
*/
spin_lock(&mm->page_table_lock);
continue_scan:
address = mm->swap_address;
if (address == TASK_SIZE || swap_mm != mm) {
/* We raced: don't count this mm but try again */
++*mmcounter;
goto out_unlock;
}
vma = find_vma(mm, address);
if (vma) {
if (address < vma->vm_start)
address = vma->vm_start;
for (;;) {
count = swap_out_vma(mm, vma, address, count, classzone);
vma = vma->vm_next;
if (!vma)
break;
/* we reach this with a lock depth of 1 and 2 */
#if 0
if (conditional_schedule_needed()) {
break_spin_lock(&mm->page_table_lock);
goto continue_scan;
}
#endif
if (!count)
goto out_unlock;
address = vma->vm_start;
}
}
/* Indicate that we reached the end of address space */
mm->swap_address = TASK_SIZE;
out_unlock:
spin_unlock(&mm->page_table_lock);
return count;
}
static int swap_out_mm(struct mm_struct * mm, int gfp_mask)
{
unsigned long address;
struct vm_area_struct* vma;
/*
* Go through process' page directory.
*/
address = mm->swap_address;
/*
* Find the proper vm-area after freezing the vma chain
* and ptes.
*/
spin_lock(&mm->page_table_lock);
vma = find_vma(mm, address);
if (vma) {
if (address < vma->vm_start)
address = vma->vm_start;
for (;;) {
int result = swap_out_vma(mm, vma, address, gfp_mask);
if (result)
return result;
if (!mm->swap_cnt)
goto out_unlock;
vma = vma->vm_next;
if (!vma)
break;
address = vma->vm_start;
}
}
/* Reset to 0 when we reach the end of address space */
mm->swap_address = 0;
mm->swap_cnt = 0;
out_unlock:
spin_unlock(&mm->page_table_lock);
/* We didn't find anything for the process */
return 0;
}
// swap_out_mm - call swap_out_vma to try to unmap a set of vma ('require' NUM pages).
int
swap_out_mm(struct mm_struct *mm, size_t require) {
assert(mm != NULL);
if (require == 0 || mm->map_count == 0) {
return 0;
}
assert(!list_empty(&(mm->mmap_list)));
uintptr_t addr = mm->swap_address;
struct vma_struct *vma;
if ((vma = find_vma(mm, addr)) == NULL) {
addr = mm->swap_address = 0;
vma = le2vma(list_next(&(mm->mmap_list)), list_link);
}
assert(vma != NULL && addr <= vma->vm_end);
if (addr < vma->vm_start) {
addr = vma->vm_start;
}
int i;
size_t free_count = 0;
for (i = 0; i <= mm->map_count; i ++) {
int ret = swap_out_vma(mm, vma, addr, require);
free_count += ret, require -= ret;
if (require == 0) {
break;
}
list_entry_t *le = list_next(&(vma->list_link));
if (le == &(mm->mmap_list)) {
le = list_next(le);
}
vma = le2vma(le, list_link);
addr = vma->vm_start;
}
return free_count;
}