mm: rename page_order() to buddy_order()

The current page_order() can only be called on pages in the buddy
allocator.  For compound pages, you have to use compound_order().  This is
confusing and led to a bug, so rename page_order() to buddy_order().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20201001152259.14932-2-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2020-10-15 20:10:15 -07:00 committed by Linus Torvalds
parent 1f0f8c0de0
commit ab130f9108
7 changed files with 29 additions and 29 deletions

View file

@ -625,7 +625,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
}
/* Found a free page, will break it into order-0 pages */
order = page_order(page);
order = buddy_order(page);
isolated = __isolate_free_page(page, order);
if (!isolated)
break;
@ -898,7 +898,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
* potential isolation targets.
*/
if (PageBuddy(page)) {
unsigned long freepage_order = page_order_unsafe(page);
unsigned long freepage_order = buddy_order_unsafe(page);
/*
* Without lock, we cannot be sure that what we got is
@ -1172,7 +1172,7 @@ static bool suitable_migration_target(struct compact_control *cc,
* the only small danger is that we skip a potentially suitable
* pageblock, so it's not worth to check order for valid range.
*/
if (page_order_unsafe(page) >= pageblock_order)
if (buddy_order_unsafe(page) >= pageblock_order)
return false;
}

View file

@ -270,16 +270,16 @@ int find_suitable_fallback(struct free_area *area, unsigned int order,
* page from being allocated in parallel and returning garbage as the order.
* If a caller does not hold page_zone(page)->lock, it must guarantee that the
* page cannot be allocated or merged in parallel. Alternatively, it must
* handle invalid values gracefully, and use page_order_unsafe() below.
* handle invalid values gracefully, and use buddy_order_unsafe() below.
*/
static inline unsigned int page_order(struct page *page)
static inline unsigned int buddy_order(struct page *page)
{
/* PageBuddy() must be checked by the caller */
return page_private(page);
}
/*
* Like page_order(), but for callers who cannot afford to hold the zone lock.
* Like buddy_order(), but for callers who cannot afford to hold the zone lock.
* PageBuddy() should be checked first by the caller to minimize race window,
* and invalid values must be handled gracefully.
*
@ -289,7 +289,7 @@ static inline unsigned int page_order(struct page *page)
* times, potentially observing different values in the tests and the actual
* use of the result.
*/
#define page_order_unsafe(page) READ_ONCE(page_private(page))
#define buddy_order_unsafe(page) READ_ONCE(page_private(page))
static inline bool is_cow_mapping(vm_flags_t flags)
{

View file

@ -792,7 +792,7 @@ static inline void clear_page_guard(struct zone *zone, struct page *page,
unsigned int order, int migratetype) {}
#endif
static inline void set_page_order(struct page *page, unsigned int order)
static inline void set_buddy_order(struct page *page, unsigned int order)
{
set_page_private(page, order);
__SetPageBuddy(page);
@ -817,7 +817,7 @@ static inline bool page_is_buddy(struct page *page, struct page *buddy,
if (!page_is_guard(buddy) && !PageBuddy(buddy))
return false;
if (page_order(buddy) != order)
if (buddy_order(buddy) != order)
return false;
/*
@ -1059,7 +1059,7 @@ static inline void __free_one_page(struct page *page,
}
done_merging:
set_page_order(page, order);
set_buddy_order(page, order);
if (fpi_flags & FPI_TO_TAIL)
to_tail = true;
@ -2178,7 +2178,7 @@ static inline void expand(struct zone *zone, struct page *page,
continue;
add_to_free_list(&page[size], zone, high, migratetype);
set_page_order(&page[size], high);
set_buddy_order(&page[size], high);
}
}
@ -2392,7 +2392,7 @@ static int move_freepages(struct zone *zone,
VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
VM_BUG_ON_PAGE(page_zone(page) != zone, page);
order = page_order(page);
order = buddy_order(page);
move_to_free_list(page, zone, order, migratetype);
page += 1 << order;
pages_moved += 1 << order;
@ -2516,7 +2516,7 @@ static inline void boost_watermark(struct zone *zone)
static void steal_suitable_fallback(struct zone *zone, struct page *page,
unsigned int alloc_flags, int start_type, bool whole_block)
{
unsigned int current_order = page_order(page);
unsigned int current_order = buddy_order(page);
int free_pages, movable_pages, alike_pages;
int old_block_type;
@ -8344,7 +8344,7 @@ struct page *has_unmovable_pages(struct zone *zone, struct page *page,
*/
if (!page_ref_count(page)) {
if (PageBuddy(page))
iter += (1 << page_order(page)) - 1;
iter += (1 << buddy_order(page)) - 1;
continue;
}
@ -8557,7 +8557,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
}
if (outer_start != start) {
order = page_order(pfn_to_page(outer_start));
order = buddy_order(pfn_to_page(outer_start));
/*
* outer_start page could be small order buddy page and
@ -8782,7 +8782,7 @@ void __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
BUG_ON(page_count(page));
BUG_ON(!PageBuddy(page));
order = page_order(page);
order = buddy_order(page);
del_page_from_free_list(page, zone, order);
pfn += (1 << order);
}
@ -8801,7 +8801,7 @@ bool is_free_buddy_page(struct page *page)
for (order = 0; order < MAX_ORDER; order++) {
struct page *page_head = page - (pfn & ((1 << order) - 1));
if (PageBuddy(page_head) && page_order(page_head) >= order)
if (PageBuddy(page_head) && buddy_order(page_head) >= order)
break;
}
spin_unlock_irqrestore(&zone->lock, flags);
@ -8838,7 +8838,7 @@ static void break_down_buddy_pages(struct zone *zone, struct page *page,
if (current_buddy != target) {
add_to_free_list(current_buddy, zone, high, migratetype);
set_page_order(current_buddy, high);
set_buddy_order(current_buddy, high);
page = next_page;
}
}
@ -8858,16 +8858,16 @@ bool take_page_off_buddy(struct page *page)
spin_lock_irqsave(&zone->lock, flags);
for (order = 0; order < MAX_ORDER; order++) {
struct page *page_head = page - (pfn & ((1 << order) - 1));
int buddy_order = page_order(page_head);
int page_order = buddy_order(page_head);
if (PageBuddy(page_head) && buddy_order >= order) {
if (PageBuddy(page_head) && page_order >= order) {
unsigned long pfn_head = page_to_pfn(page_head);
int migratetype = get_pfnblock_migratetype(page_head,
pfn_head);
del_page_from_free_list(page_head, zone, buddy_order);
del_page_from_free_list(page_head, zone, page_order);
break_down_buddy_pages(zone, page_head, page, 0,
buddy_order, migratetype);
page_order, migratetype);
ret = true;
break;
}

View file

@ -88,7 +88,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype)
* these pages to be merged.
*/
if (PageBuddy(page)) {
order = page_order(page);
order = buddy_order(page);
if (order >= pageblock_order) {
pfn = page_to_pfn(page);
buddy_pfn = __find_buddy_pfn(pfn, order);
@ -261,7 +261,7 @@ __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn,
* the correct MIGRATE_ISOLATE freelist. There is no
* simple way to verify that as VM_BUG_ON(), though.
*/
pfn += 1 << page_order(page);
pfn += 1 << buddy_order(page);
else if ((flags & MEMORY_OFFLINE) && PageHWPoison(page))
/* A HWPoisoned page cannot be also PageBuddy */
pfn++;

View file

@ -295,7 +295,7 @@ void pagetypeinfo_showmixedcount_print(struct seq_file *m,
if (PageBuddy(page)) {
unsigned long freepage_order;
freepage_order = page_order_unsafe(page);
freepage_order = buddy_order_unsafe(page);
if (freepage_order < MAX_ORDER)
pfn += (1UL << freepage_order) - 1;
continue;
@ -490,7 +490,7 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos)
page = pfn_to_page(pfn);
if (PageBuddy(page)) {
unsigned long freepage_order = page_order_unsafe(page);
unsigned long freepage_order = buddy_order_unsafe(page);
if (freepage_order < MAX_ORDER)
pfn += (1UL << freepage_order) - 1;
@ -584,7 +584,7 @@ static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
* heavy lock contention.
*/
if (PageBuddy(page)) {
unsigned long order = page_order_unsafe(page);
unsigned long order = buddy_order_unsafe(page);
if (order > 0 && order < MAX_ORDER)
pfn += (1UL << order) - 1;

View file

@ -92,7 +92,7 @@ page_reporting_drain(struct page_reporting_dev_info *prdev,
* report on the new larger page when we make our way
* up to that higher order.
*/
if (PageBuddy(page) && page_order(page) == order)
if (PageBuddy(page) && buddy_order(page) == order)
__SetPageReported(page);
} while ((sg = sg_next(sg)));

View file

@ -60,7 +60,7 @@ static struct page * __meminit shuffle_valid_page(struct zone *zone,
* ...is the page on the same list as the page we will
* shuffle it with?
*/
if (page_order(page) != order)
if (buddy_order(page) != order)
return NULL;
return page;