mm/debug_pagealloc.c: clean-up guard page handling code

[cascardo/linux.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0c34633..e150ba9 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -637,17 +637,20 @@ static int __init debug_guardpage_minorder_setup(char *buf)
 }
 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
 
-static inline void set_page_guard(struct zone *zone, struct page *page,
+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;
+               return false;
+
+       if (order >= debug_guardpage_minorder())
+               return false;
 
        page_ext = lookup_page_ext(page);
        if (unlikely(!page_ext))
-               return;
+               return false;
 
        __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
 
@@ -655,6 +658,8 @@ static inline void set_page_guard(struct zone *zone, struct page *page,
        set_page_private(page, order);
        /* Guard pages are not available for any usage */
        __mod_zone_freepage_state(zone, -(1 << order), migratetype);
+
+       return true;
 }
 
 static inline void clear_page_guard(struct zone *zone, struct page *page,
@@ -677,8 +682,8 @@ static inline void clear_page_guard(struct zone *zone, struct page *page,
 }
 #else
 struct page_ext_operations debug_guardpage_ops = { NULL, };
-static inline void set_page_guard(struct zone *zone, struct page *page,
-                               unsigned int order, int migratetype) {}
+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,
                                unsigned int order, int migratetype) {}
 #endif
@@ -1622,18 +1627,15 @@ static inline void expand(struct zone *zone, struct page *page,
                size >>= 1;
                VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
 
-               if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
-                       debug_guardpage_enabled() &&
-                       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
-                        */
-                       set_page_guard(zone, &page[size], high, migratetype);
+               /*
+                * 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
+                */
+               if (set_page_guard(zone, &page[size], high, migratetype))
                        continue;
-               }
+
                list_add(&page[size].lru, &area->free_list[migratetype]);
                area->nr_free++;
                set_page_order(&page[size], high);