From 3972f6bb1c6ae1d32dcf2e4ff635d24b77f26dcb Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Thu, 11 Jul 2019 20:55:13 -0700 Subject: mm, debug_pagealloc: use a page type instead of page_ext flag When debug_pagealloc is enabled, we currently allocate the page_ext array to mark guard pages with the PAGE_EXT_DEBUG_GUARD flag. Now that we have the page_type field in struct page, we can use that instead, as guard pages are neither PageSlab nor mapped to userspace. This reduces memory overhead when debug_pagealloc is enabled and there are no other features requiring the page_ext array. Link: http://lkml.kernel.org/r/20190603143451.27353-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka Cc: Joonsoo Kim Cc: Matthew Wilcox Cc: "Kirill A. Shutemov" Cc: Mel Gorman Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 40 ++++++---------------------------------- 1 file changed, 6 insertions(+), 34 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 26b6ad8b065d..ae56e8feec0c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -50,7 +50,6 @@ #include #include #include -#include #include #include #include @@ -668,18 +667,6 @@ static int __init early_debug_pagealloc(char *buf) } early_param("debug_pagealloc", early_debug_pagealloc); -static bool need_debug_guardpage(void) -{ - /* If we don't use debug_pagealloc, we don't need guard page */ - if (!debug_pagealloc_enabled()) - return false; - - if (!debug_guardpage_minorder()) - return false; - - return true; -} - static void init_debug_guardpage(void) { if (!debug_pagealloc_enabled()) @@ -691,11 +678,6 @@ static void init_debug_guardpage(void) static_branch_enable(&_debug_guardpage_enabled); } -struct page_ext_operations debug_guardpage_ops = { - .need = need_debug_guardpage, - .init = init_debug_guardpage, -}; - static int __init debug_guardpage_minorder_setup(char *buf) { unsigned long res; @@ -713,20 +695,13 @@ early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup); static inline bool set_page_guard(struct zone *zone, struct page *page, unsigned int order, int migratetype) { - struct page_ext *page_ext; - if (!debug_guardpage_enabled()) return false; if (order >= debug_guardpage_minorder()) return false; - page_ext = lookup_page_ext(page); - if (unlikely(!page_ext)) - return false; - - __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); - + __SetPageGuard(page); INIT_LIST_HEAD(&page->lru); set_page_private(page, order); /* Guard pages are not available for any usage */ @@ -738,23 +713,16 @@ static inline bool set_page_guard(struct zone *zone, struct page *page, static inline void clear_page_guard(struct zone *zone, struct page *page, unsigned int order, int migratetype) { - struct page_ext *page_ext; - if (!debug_guardpage_enabled()) return; - page_ext = lookup_page_ext(page); - if (unlikely(!page_ext)) - return; - - __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); + __ClearPageGuard(page); set_page_private(page, 0); if (!is_migrate_isolate(migratetype)) __mod_zone_freepage_state(zone, (1 << order), migratetype); } #else -struct page_ext_operations debug_guardpage_ops; static inline bool set_page_guard(struct zone *zone, struct page *page, unsigned int order, int migratetype) { return false; } static inline void clear_page_guard(struct zone *zone, struct page *page, @@ -1930,6 +1898,10 @@ void __init page_alloc_init_late(void) for_each_populated_zone(zone) set_zone_contiguous(zone); + +#ifdef CONFIG_DEBUG_PAGEALLOC + init_debug_guardpage(); +#endif } #ifdef CONFIG_CMA -- cgit v1.2.3