On 11/07/2014 08:35 AM, Joonsoo Kim wrote:
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>
Acked-by: Vlastimil Babka <vbabka@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);
--
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