static struct page * rmqueue(zone_t *zone, unsigned int order)
{
free_area_t * area = zone->free_area + order;
unsigned int curr_order = order;
struct list_head *head, *curr;
unsigned long flags;
struct page *page;
int i;
spin_lock_irqsave(&zone->lock, flags);
do {
head = &area->free_list;
curr = head->next;
if (curr != head) {
unsigned int index;
page = list_entry(curr, struct page, list);
if (BAD_RANGE(zone,page))
BUG();
list_del(curr);
index = page - zone->zone_mem_map;
if (curr_order != MAX_ORDER-1)
MARK_USED(index, curr_order, area);
zone->free_pages -= 1UL << order;
page = expand(zone, page, index, order, curr_order, area);
spin_unlock_irqrestore(&zone->lock, flags);
set_page_count(page, 1);
if (BAD_RANGE(zone,page))
BUG();
if (PageLRU(page))
BUG();
if (PageActive(page))
BUG();
/*
* we need to reference all the pages for this order,
* otherwise if anyone accesses one of the pages with
* (get/put) it * will be freed :-(
*/
for (i = 1; i < (1 << order); i++)
set_page_count(&page[i], 1);
return page;
}
curr_order++;
area++;
} while (curr_order < MAX_ORDER);
static inline struct page * expand (zone_t *zone, struct page *page,
unsigned long index, int low, int high, free_area_t * area)
{
unsigned long size = 1 << high;
while (high > low) {
if (BAD_RANGE(zone,page))
BUG();
area--;
high--;
size >>= 1;
list_add(&(page)->list, &(area)->free_list);
MARK_USED(index, high, area);
index += size;
page += size;
}
if (BAD_RANGE(zone,page))
BUG();
return page;
}
static struct page * rmqueue(zone_t *zone, unsigned int order)
{
free_area_t * area = zone->free_area + order;
unsigned int curr_order = order;
struct list_head *head, *curr;
unsigned long flags;
struct page *page;
spin_lock_irqsave(&zone->lock, flags);
do {
head = &area->free_list;
curr = head->next;
if (curr != head) {
unsigned int index;
page = list_entry(curr, struct page, list);
if (BAD_RANGE(zone,page))
BUG();
list_del(curr);
index = page - zone->zone_mem_map;
if (curr_order != MAX_ORDER-1)
MARK_USED(index, curr_order, area);
zone->free_pages -= 1UL << order;
page = expand(zone, page, index, order, curr_order, area);
spin_unlock_irqrestore(&zone->lock, flags);
set_page_count(page, 1);
if (BAD_RANGE(zone,page))
BUG();
if (PageLRU(page))
BUG();
if (PageActive(page))
BUG();
return page;
}
curr_order++;
area++;
} while (curr_order < MAX_ORDER);
static void __free_pages_ok (struct page *page, unsigned int order)
{
unsigned long index, page_idx, mask, flags;
free_area_t *area;
struct page *base;
zone_t *zone;
/*
* Yes, think what happens when other parts of the kernel take
* a reference to a page in order to pin it for io. -ben
*/
if (PageLRU(page)) {
if (unlikely(in_interrupt()))
BUG();
lru_cache_del(page);
}
if (page->buffers)
BUG();
if (page->mapping)
BUG();
if (!VALID_PAGE(page))
BUG();
if (PageLocked(page))
BUG();
if (PageActive(page))
BUG();
page->flags &= ~((1<<PG_referenced) | (1<<PG_dirty));
if (current->flags & PF_FREE_PAGES)
goto local_freelist;
back_local_freelist:
zone = page_zone(page);
mask = (~0UL) << order;
base = zone->zone_mem_map;
page_idx = page - base;
if (page_idx & ~mask)
BUG();
index = page_idx >> (1 + order);
area = zone->free_area + order;
spin_lock_irqsave(&zone->lock, flags);
zone->free_pages -= mask;
while (mask + (1 << (MAX_ORDER-1))) {
struct page *buddy1, *buddy2;
if (area >= zone->free_area + MAX_ORDER)
BUG();
if (!__test_and_change_bit(index, area->map))
/*
* the buddy page is still allocated.
*/
break;
/*
* Move the buddy up one level.
* This code is taking advantage of the identity:
* -mask = 1+~mask
*/
buddy1 = base + (page_idx ^ -mask);
buddy2 = base + page_idx;
if (BAD_RANGE(zone,buddy1))
BUG();
if (BAD_RANGE(zone,buddy2))
BUG();
list_del(&buddy1->list);
mask <<= 1;
area++;
index >>= 1;
page_idx &= mask;
}
list_add(&(base + page_idx)->list, &area->free_list);
spin_unlock_irqrestore(&zone->lock, flags);
return;
local_freelist:
if (current->nr_local_pages)
goto back_local_freelist;
if (in_interrupt())
goto back_local_freelist;
list_add(&page->list, ¤t->local_pages);
page->index = order;
current->nr_local_pages++;
}
static void __free_pages_ok (struct page *page, unsigned int order)
{
unsigned long index, page_idx, mask, flags;
free_area_t *area;
struct page *base;
zone_t *zone;
if (PageLRU(page))
lru_cache_del(page);
if (page->buffers)
BUG();
if (page->mapping)
BUG();
if (!VALID_PAGE(page))
BUG();
if (PageSwapCache(page))
BUG();
if (PageLocked(page))
BUG();
if (PageLRU(page))
BUG();
if (PageActive(page))
BUG();
TRACE_MEMORY(TRACE_EV_MEMORY_PAGE_FREE, order);
page->flags &= ~((1<<PG_referenced) | (1<<PG_dirty));
if (current->flags & PF_FREE_PAGES)
goto local_freelist;
back_local_freelist:
zone = page->zone;
mask = (~0UL) << order;
base = zone->zone_mem_map;
page_idx = page - base;
if (page_idx & ~mask)
BUG();
index = page_idx >> (1 + order);
area = zone->free_area + order;
spin_lock_irqsave(&zone->lock, flags);
zone->free_pages -= mask;
while (mask + (1 << (MAX_ORDER-1))) {
struct page *buddy1, *buddy2;
if (area >= zone->free_area + MAX_ORDER)
BUG();
if (!__test_and_change_bit(index, area->map))
/*
* the buddy page is still allocated.
*/
break;
/*
* Move the buddy up one level.
*/
buddy1 = base + (page_idx ^ -mask);
buddy2 = base + page_idx;
if (BAD_RANGE(zone,buddy1))
BUG();
if (BAD_RANGE(zone,buddy2))
BUG();
memlist_del(&buddy1->list);
mask <<= 1;
area++;
index >>= 1;
page_idx &= mask;
}
memlist_add_head(&(base + page_idx)->list, &area->free_list);
spin_unlock_irqrestore(&zone->lock, flags);
return;
local_freelist:
if (current->nr_local_pages)
goto back_local_freelist;
if (in_interrupt())
goto back_local_freelist;
list_add(&page->list, ¤t->local_pages);
page->index = order;
current->nr_local_pages++;
}
static void __free_pages_ok (struct page *page, unsigned int order)
{
unsigned long index, page_idx, mask, flags;
free_area_t *area;
struct page *base;
zone_t *zone;
/*
* Subtle. We do not want to test this in the inlined part of
* __free_page() - it's a rare condition and just increases
* cache footprint unnecesserily. So we do an 'incorrect'
* decrement on page->count for reserved pages, but this part
* makes it safe.
*/
if (PageReserved(page))
return;
/*
* Yes, think what happens when other parts of the kernel take
* a reference to a page in order to pin it for io. -ben
*/
if (PageLRU(page)) {
if (unlikely(in_interrupt())) {
unsigned long flags;
spin_lock_irqsave(&free_pages_ok_no_irq_lock, flags);
page->next_hash = free_pages_ok_no_irq_head;
free_pages_ok_no_irq_head = page;
page->index = order;
spin_unlock_irqrestore(&free_pages_ok_no_irq_lock, flags);
schedule_task(&free_pages_ok_no_irq_task);
return;
}
lru_cache_del(page);
}
if (page->buffers)
BUG();
if (page->mapping)
BUG();
if (!VALID_PAGE(page))
BUG();
if (PageLocked(page))
BUG();
if (PageActive(page))
BUG();
ClearPageReferenced(page);
ClearPageDirty(page);
/* de-reference all the pages for this order */
for (page_idx = 1; page_idx < (1 << order); page_idx++)
set_page_count(&page[page_idx], 0);
if (current->flags & PF_FREE_PAGES)
goto local_freelist;
back_local_freelist:
zone = page_zone(page);
mask = (~0UL) << order;
base = zone->zone_mem_map;
page_idx = page - base;
if (page_idx & ~mask)
BUG();
index = page_idx >> (1 + order);
area = zone->free_area + order;
spin_lock_irqsave(&zone->lock, flags);
zone->free_pages -= mask;
while (mask + (1 << (MAX_ORDER-1))) {
struct page *buddy1, *buddy2;
if (area >= zone->free_area + MAX_ORDER)
BUG();
if (!__test_and_change_bit(index, area->map))
/*
* the buddy page is still allocated.
*/
break;
/*
* Move the buddy up one level.
* This code is taking advantage of the identity:
* -mask = 1+~mask
*/
buddy1 = base + (page_idx ^ -mask);
buddy2 = base + page_idx;
if (BAD_RANGE(zone,buddy1))
BUG();
if (BAD_RANGE(zone,buddy2))
BUG();
list_del(&buddy1->list);
mask <<= 1;
area++;
index >>= 1;
page_idx &= mask;
}
list_add(&(base + page_idx)->list, &area->free_list);
spin_unlock_irqrestore(&zone->lock, flags);
return;
local_freelist:
if (current->nr_local_pages)
goto back_local_freelist;
if (in_interrupt())
goto back_local_freelist;
list_add(&page->list, ¤t->local_pages);
page->index = order;
current->nr_local_pages++;
}
