Page guard is used by debug-pagealloc feature. Currently, it is open-coded, but, I think that more abstraction of it makes core page allocator code more readable. There is no functional difference. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> --- mm/page_alloc.c | 38 +++++++++++++++++++------------------- 1 file changed, 19 insertions(+), 19 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d673f64..c0dbede 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -440,18 +440,29 @@ static int __init debug_guardpage_minorder_setup(char *buf) } __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup); -static inline void set_page_guard_flag(struct page *page) +static inline void set_page_guard(struct zone *zone, struct page *page, + unsigned int order, int migratetype) { __set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags); + INIT_LIST_HEAD(&page->lru); + set_page_private(page, order); + /* Guard pages are not available for any usage */ + __mod_zone_freepage_state(zone, -(1 << order), migratetype); } -static inline void clear_page_guard_flag(struct page *page) +static inline void clear_page_guard(struct zone *zone, struct page *page, + unsigned int order, int migratetype) { __clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags); + set_page_private(page, 0); + if (!is_migrate_isolate(migratetype)) + __mod_zone_freepage_state(zone, (1 << order), migratetype); } #else -static inline void set_page_guard_flag(struct page *page) { } -static inline void clear_page_guard_flag(struct page *page) { } +static inline void set_page_guard(struct zone *zone, struct page *page, + unsigned int order, int migratetype) {} +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) @@ -582,12 +593,7 @@ static inline void __free_one_page(struct page *page, * merge with it and move up one order. */ if (page_is_guard(buddy)) { - clear_page_guard_flag(buddy); - set_page_private(buddy, 0); - if (!is_migrate_isolate(migratetype)) { - __mod_zone_freepage_state(zone, 1 << order, - migratetype); - } + clear_page_guard(zone, buddy, order, migratetype); } else { list_del(&buddy->lru); zone->free_area[order].nr_free--; @@ -862,23 +868,17 @@ static inline void expand(struct zone *zone, struct page *page, size >>= 1; VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]); -#ifdef CONFIG_DEBUG_PAGEALLOC - if (high < debug_guardpage_minorder()) { + if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) && + high < debug_guardpage_minorder()) { /* * Mark as guard pages (or page), that will allow to * merge back to allocator when buddy will be freed. * Corresponding page table entries will not be touched, * pages will stay not present in virtual address space */ - INIT_LIST_HEAD(&page[size].lru); - set_page_guard_flag(&page[size]); - set_page_private(&page[size], high); - /* Guard pages are not available for any usage */ - __mod_zone_freepage_state(zone, -(1 << high), - migratetype); + set_page_guard(zone, &page[size], high, migratetype); continue; } -#endif list_add(&page[size].lru, &area->free_list[migratetype]); area->nr_free++; set_page_order(&page[size], high); -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>