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Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r--mm/page_alloc.c70
1 files changed, 57 insertions, 13 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index dc523a1f270..97d6827c7d6 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -51,6 +51,7 @@ nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL;
EXPORT_SYMBOL(node_possible_map);
unsigned long totalram_pages __read_mostly;
unsigned long totalhigh_pages __read_mostly;
+unsigned long totalreserve_pages __read_mostly;
long nr_swap_pages;
int percpu_pagelist_fraction;
@@ -151,7 +152,8 @@ static void bad_page(struct page *page)
1 << PG_reclaim |
1 << PG_slab |
1 << PG_swapcache |
- 1 << PG_writeback );
+ 1 << PG_writeback |
+ 1 << PG_buddy );
set_page_count(page, 0);
reset_page_mapcount(page);
page->mapping = NULL;
@@ -236,12 +238,12 @@ static inline unsigned long page_order(struct page *page) {
static inline void set_page_order(struct page *page, int order) {
set_page_private(page, order);
- __SetPagePrivate(page);
+ __SetPageBuddy(page);
}
static inline void rmv_page_order(struct page *page)
{
- __ClearPagePrivate(page);
+ __ClearPageBuddy(page);
set_page_private(page, 0);
}
@@ -280,11 +282,13 @@ __find_combined_index(unsigned long page_idx, unsigned int order)
* This function checks whether a page is free && is the buddy
* we can do coalesce a page and its buddy if
* (a) the buddy is not in a hole &&
- * (b) the buddy is free &&
- * (c) the buddy is on the buddy system &&
- * (d) a page and its buddy have the same order.
- * for recording page's order, we use page_private(page) and PG_private.
+ * (b) the buddy is in the buddy system &&
+ * (c) a page and its buddy have the same order.
+ *
+ * For recording whether a page is in the buddy system, we use PG_buddy.
+ * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
*
+ * For recording page's order, we use page_private(page).
*/
static inline int page_is_buddy(struct page *page, int order)
{
@@ -293,10 +297,10 @@ static inline int page_is_buddy(struct page *page, int order)
return 0;
#endif
- if (PagePrivate(page) &&
- (page_order(page) == order) &&
- page_count(page) == 0)
+ if (PageBuddy(page) && page_order(page) == order) {
+ BUG_ON(page_count(page) != 0);
return 1;
+ }
return 0;
}
@@ -313,7 +317,7 @@ static inline int page_is_buddy(struct page *page, int order)
* as necessary, plus some accounting needed to play nicely with other
* parts of the VM system.
* At each level, we keep a list of pages, which are heads of continuous
- * free pages of length of (1 << order) and marked with PG_Private.Page's
+ * free pages of length of (1 << order) and marked with PG_buddy. Page's
* order is recorded in page_private(page) field.
* So when we are allocating or freeing one, we can derive the state of the
* other. That is, if we allocate a small block, and both were
@@ -376,7 +380,8 @@ static inline int free_pages_check(struct page *page)
1 << PG_slab |
1 << PG_swapcache |
1 << PG_writeback |
- 1 << PG_reserved ))))
+ 1 << PG_reserved |
+ 1 << PG_buddy ))))
bad_page(page);
if (PageDirty(page))
__ClearPageDirty(page);
@@ -524,7 +529,8 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
1 << PG_slab |
1 << PG_swapcache |
1 << PG_writeback |
- 1 << PG_reserved ))))
+ 1 << PG_reserved |
+ 1 << PG_buddy ))))
bad_page(page);
/*
@@ -2472,6 +2478,38 @@ void __init page_alloc_init(void)
}
/*
+ * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
+ * or min_free_kbytes changes.
+ */
+static void calculate_totalreserve_pages(void)
+{
+ struct pglist_data *pgdat;
+ unsigned long reserve_pages = 0;
+ int i, j;
+
+ for_each_online_pgdat(pgdat) {
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ struct zone *zone = pgdat->node_zones + i;
+ unsigned long max = 0;
+
+ /* Find valid and maximum lowmem_reserve in the zone */
+ for (j = i; j < MAX_NR_ZONES; j++) {
+ if (zone->lowmem_reserve[j] > max)
+ max = zone->lowmem_reserve[j];
+ }
+
+ /* we treat pages_high as reserved pages. */
+ max += zone->pages_high;
+
+ if (max > zone->present_pages)
+ max = zone->present_pages;
+ reserve_pages += max;
+ }
+ }
+ totalreserve_pages = reserve_pages;
+}
+
+/*
* setup_per_zone_lowmem_reserve - called whenever
* sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
* has a correct pages reserved value, so an adequate number of
@@ -2502,6 +2540,9 @@ static void setup_per_zone_lowmem_reserve(void)
}
}
}
+
+ /* update totalreserve_pages */
+ calculate_totalreserve_pages();
}
/*
@@ -2556,6 +2597,9 @@ void setup_per_zone_pages_min(void)
zone->pages_high = zone->pages_min + tmp / 2;
spin_unlock_irqrestore(&zone->lru_lock, flags);
}
+
+ /* update totalreserve_pages */
+ calculate_totalreserve_pages();
}
/*