Commit 13ad59df authored by Vlastimil Babka's avatar Vlastimil Babka Committed by Linus Torvalds

mm, page_alloc: avoid page_to_pfn() when merging buddies

On architectures that allow memory holes, page_is_buddy() has to perform
page_to_pfn() to check for the memory hole.  After the previous patch,
we have the pfn already available in __free_one_page(), which is the
only caller of page_is_buddy(), so move the check there and avoid
page_to_pfn().

Link: http://lkml.kernel.org/r/20161216120009.20064-2-vbabka@suse.czSigned-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarMel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 76741e77
...@@ -714,7 +714,7 @@ static inline void rmv_page_order(struct page *page) ...@@ -714,7 +714,7 @@ static inline void rmv_page_order(struct page *page)
/* /*
* This function checks whether a page is free && is the buddy * This function checks whether a page is free && is the buddy
* we can do coalesce a page and its buddy if * we can do coalesce a page and its buddy if
* (a) the buddy is not in a hole && * (a) the buddy is not in a hole (check before calling!) &&
* (b) the buddy is in the buddy system && * (b) the buddy is in the buddy system &&
* (c) a page and its buddy have the same order && * (c) a page and its buddy have the same order &&
* (d) a page and its buddy are in the same zone. * (d) a page and its buddy are in the same zone.
...@@ -729,9 +729,6 @@ static inline void rmv_page_order(struct page *page) ...@@ -729,9 +729,6 @@ static inline void rmv_page_order(struct page *page)
static inline int page_is_buddy(struct page *page, struct page *buddy, static inline int page_is_buddy(struct page *page, struct page *buddy,
unsigned int order) unsigned int order)
{ {
if (!pfn_valid_within(page_to_pfn(buddy)))
return 0;
if (page_is_guard(buddy) && page_order(buddy) == order) { if (page_is_guard(buddy) && page_order(buddy) == order) {
if (page_zone_id(page) != page_zone_id(buddy)) if (page_zone_id(page) != page_zone_id(buddy))
return 0; return 0;
...@@ -808,6 +805,9 @@ static inline void __free_one_page(struct page *page, ...@@ -808,6 +805,9 @@ static inline void __free_one_page(struct page *page,
while (order < max_order - 1) { while (order < max_order - 1) {
buddy_pfn = __find_buddy_pfn(pfn, order); buddy_pfn = __find_buddy_pfn(pfn, order);
buddy = page + (buddy_pfn - pfn); buddy = page + (buddy_pfn - pfn);
if (!pfn_valid_within(buddy_pfn))
goto done_merging;
if (!page_is_buddy(page, buddy, order)) if (!page_is_buddy(page, buddy, order))
goto done_merging; goto done_merging;
/* /*
...@@ -862,7 +862,7 @@ static inline void __free_one_page(struct page *page, ...@@ -862,7 +862,7 @@ static inline void __free_one_page(struct page *page,
* so it's less likely to be used soon and more likely to be merged * so it's less likely to be used soon and more likely to be merged
* as a higher order page * as a higher order page
*/ */
if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) { if ((order < MAX_ORDER-2) && pfn_valid_within(buddy_pfn)) {
struct page *higher_page, *higher_buddy; struct page *higher_page, *higher_buddy;
combined_pfn = buddy_pfn & pfn; combined_pfn = buddy_pfn & pfn;
higher_page = page + (combined_pfn - pfn); higher_page = page + (combined_pfn - pfn);
......
...@@ -106,7 +106,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype) ...@@ -106,7 +106,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype)
buddy_pfn = __find_buddy_pfn(pfn, order); buddy_pfn = __find_buddy_pfn(pfn, order);
buddy = page + (buddy_pfn - pfn); buddy = page + (buddy_pfn - pfn);
if (pfn_valid_within(page_to_pfn(buddy)) && if (pfn_valid_within(buddy_pfn) &&
!is_migrate_isolate_page(buddy)) { !is_migrate_isolate_page(buddy)) {
__isolate_free_page(page, order); __isolate_free_page(page, order);
isolated_page = true; isolated_page = true;
......
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