@@ -35,13 +35,37 @@
*/
#define PAGE_ALLOC_COSTLY_ORDER 3
-#define MIGRATE_UNMOVABLE 0
-#define MIGRATE_RECLAIMABLE 1
-#define MIGRATE_MOVABLE 2
-#define MIGRATE_PCPTYPES 3 /* the number of types on the pcp lists */
-#define MIGRATE_RESERVE 3
-#define MIGRATE_ISOLATE 4 /* can't allocate from here */
-#define MIGRATE_TYPES 5
+enum {
+ MIGRATE_UNMOVABLE,
+ MIGRATE_RECLAIMABLE,
+ MIGRATE_MOVABLE,
+ MIGRATE_PCPTYPES, /* the number of types on the pcp lists */
+ MIGRATE_RESERVE = MIGRATE_PCPTYPES,
+#ifdef CONFIG_MIGRATE_CMA
+ /*
+ * MIGRATE_CMA migration type is designed to mimic the way
+ * ZONE_MOVABLE works. Only movable pages can be allocated
+ * from MIGRATE_CMA pageblocks and page allocator never
+ * implicitly change migration type of MIGRATE_CMA pageblock.
+ *
+ * The way to use it is to change migratetype of a range of
+ * pageblocks to MIGRATE_CMA which can be done by
+ * __free_pageblock_cma() function. What is important though
+ * is that a range of pageblocks must be aligned to
+ * MAX_ORDER_NR_PAGES should biggest page be bigger then
+ * a single pageblock.
+ */
+ MIGRATE_CMA,
+#endif
+ MIGRATE_ISOLATE, /* can't allocate from here */
+ MIGRATE_TYPES
+};
+
+#ifdef CONFIG_MIGRATE_CMA
+# define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
+#else
+# define is_migrate_cma(migratetype) false
+#endif
#define for_each_migratetype_order(order, type) \
for (order = 0; order < MAX_ORDER; order++) \
@@ -54,6 +78,11 @@ static inline int get_pageblock_migratetype(struct page *page)
return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end);
}
+static inline bool is_pageblock_cma(struct page *page)
+{
+ return is_migrate_cma(get_pageblock_migratetype(page));
+}
+
struct free_area {
struct list_head free_list[MIGRATE_TYPES];
unsigned long nr_free;
@@ -343,6 +343,20 @@ config CMA
For more information see <include/linux/cma.h>. If unsure, say "n".
+config MIGRATE_CMA
+ bool "Use MIGRATE_CMA migratetype"
+ depends on CMA
+ default y
+ help
+ This enables the use the MIGRATE_CMA migrate type in the CMA.
+ MIGRATE_CMA lets CMA work on almost arbitrary memory range and
+ not only inside ZONE_MOVABLE.
+
+ This option can also be selected by code that uses MIGRATE_CMA
+ even if CMA is not present.
+
+ If unsure, say "y".
+
config CMA_DEBUG
bool "CMA debug messages (DEVELOPEMENT)"
depends on CMA
@@ -113,6 +113,16 @@ static bool suitable_migration_target(struct page *page)
if (migratetype == MIGRATE_ISOLATE || migratetype == MIGRATE_RESERVE)
return false;
+ /* Keep MIGRATE_CMA alone as well. */
+ /*
+ * XXX Revisit. We currently cannot let compaction touch CMA
+ * pages since compaction insists on changing their migration
+ * type to MIGRATE_MOVABLE (see split_free_page() called from
+ * isolate_freepages_block() above).
+ */
+ if (is_migrate_cma(migratetype))
+ return false;
+
/* If the page is a large free page, then allow migration */
if (PageBuddy(page) && page_order(page) >= pageblock_order)
return true;
@@ -49,6 +49,9 @@ extern void putback_lru_page(struct page *page);
* in mm/page_alloc.c
*/
extern void __free_pages_bootmem(struct page *page, unsigned int order);
+#ifdef CONFIG_MIGRATE_CMA
+extern void __free_pageblock_cma(struct page *page);
+#endif
extern void prep_compound_page(struct page *page, unsigned long order);
#ifdef CONFIG_MEMORY_FAILURE
extern bool is_free_buddy_page(struct page *page);
@@ -717,6 +717,30 @@ void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
}
}
+#ifdef CONFIG_MIGRATE_CMA
+
+/*
+ * Free whole pageblock and set it's migration type to MIGRATE_CMA.
+ */
+void __init __free_pageblock_cma(struct page *page)
+{
+ struct page *p = page;
+ unsigned i = pageblock_nr_pages;
+
+ prefetchw(p);
+ do {
+ if (--i)
+ prefetchw(p + 1);
+ __ClearPageReserved(p);
+ set_page_count(p, 0);
+ } while (++p, i);
+
+ set_page_refcounted(page);
+ set_pageblock_migratetype(page, MIGRATE_CMA);
+ __free_pages(page, pageblock_order);
+}
+
+#endif
/*
* The order of subdivision here is critical for the IO subsystem.
@@ -824,11 +848,15 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
* This array describes the order lists are fallen back to when
* the free lists for the desirable migrate type are depleted
*/
-static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
+static int fallbacks[MIGRATE_TYPES][4] = {
[MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
[MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
+#ifdef CONFIG_MIGRATE_CMA
+ [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_CMA , MIGRATE_RESERVE },
+#else
[MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
- [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */
+#endif
+ [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
};
/*
@@ -924,12 +952,12 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
/* Find the largest possible block of pages in the other list */
for (current_order = MAX_ORDER-1; current_order >= order;
--current_order) {
- for (i = 0; i < MIGRATE_TYPES - 1; i++) {
+ for (i = 0; i < ARRAY_SIZE(fallbacks[0]); i++) {
migratetype = fallbacks[start_migratetype][i];
/* MIGRATE_RESERVE handled later if necessary */
if (migratetype == MIGRATE_RESERVE)
- continue;
+ break;
area = &(zone->free_area[current_order]);
if (list_empty(&area->free_list[migratetype]))
@@ -944,19 +972,29 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
* pages to the preferred allocation list. If falling
* back for a reclaimable kernel allocation, be more
* agressive about taking ownership of free pages
+ *
+ * On the other hand, never change migration
+ * type of MIGRATE_CMA pageblocks nor move CMA
+ * pages on different free lists. We don't
+ * want unmovable pages to be allocated from
+ * MIGRATE_CMA areas.
*/
- if (unlikely(current_order >= (pageblock_order >> 1)) ||
- start_migratetype == MIGRATE_RECLAIMABLE ||
- page_group_by_mobility_disabled) {
- unsigned long pages;
+ if (!is_pageblock_cma(page) &&
+ (unlikely(current_order >= pageblock_order / 2) ||
+ start_migratetype == MIGRATE_RECLAIMABLE ||
+ page_group_by_mobility_disabled)) {
+ int pages;
pages = move_freepages_block(zone, page,
- start_migratetype);
+ start_migratetype);
- /* Claim the whole block if over half of it is free */
+ /*
+ * Claim the whole block if over half
+ * of it is free
+ */
if (pages >= (1 << (pageblock_order-1)) ||
- page_group_by_mobility_disabled)
+ page_group_by_mobility_disabled)
set_pageblock_migratetype(page,
- start_migratetype);
+ start_migratetype);
migratetype = start_migratetype;
}
@@ -966,11 +1004,14 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
rmv_page_order(page);
/* Take ownership for orders >= pageblock_order */
- if (current_order >= pageblock_order)
+ if (current_order >= pageblock_order &&
+ !is_pageblock_cma(page))
change_pageblock_range(page, current_order,
start_migratetype);
- expand(zone, page, order, current_order, area, migratetype);
+ expand(zone, page, order, current_order, area,
+ is_migrate_cma(start_migratetype)
+ ? start_migratetype : migratetype);
trace_mm_page_alloc_extfrag(page, order, current_order,
start_migratetype, migratetype);
@@ -1042,7 +1083,12 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
list_add(&page->lru, list);
else
list_add_tail(&page->lru, list);
- set_page_private(page, migratetype);
+#ifdef CONFIG_MIGRATE_CMA
+ if (is_pageblock_cma(page))
+ set_page_private(page, MIGRATE_CMA);
+ else
+#endif
+ set_page_private(page, migratetype);
list = &page->lru;
}
__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
@@ -1178,8 +1224,8 @@ void free_hot_cold_page(struct page *page, int cold)
/*
* We only track unmovable, reclaimable and movable on pcp lists.
* Free ISOLATE pages back to the allocator because they are being
- * offlined but treat RESERVE as movable pages so we can get those
- * areas back if necessary. Otherwise, we may have to free
+ * offlined but treat RESERVE and CMA as movable pages so we can get
+ * those areas back if necessary. Otherwise, we may have to free
* excessively into the page allocator
*/
if (migratetype >= MIGRATE_PCPTYPES) {
@@ -1272,7 +1318,9 @@ int split_free_page(struct page *page)
if (order >= pageblock_order - 1) {
struct page *endpage = page + (1 << order) - 1;
for (; page < endpage; page += pageblock_nr_pages)
- set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+ if (!is_pageblock_cma(page))
+ set_pageblock_migratetype(page,
+ MIGRATE_MOVABLE);
}
return 1 << order;
@@ -5309,7 +5357,8 @@ __count_immobile_pages(struct zone *zone, struct page *page, int count)
if (zone_idx(zone) == ZONE_MOVABLE)
return true;
- if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE)
+ if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE ||
+ is_pageblock_cma(page))
return true;
pfn = page_to_pfn(page);