[PATCH 11/22] mm: page allocator: Shrink the magazine to the migratetypes in use

Mel Gorman
2013-05-08T16:08:38Z

A full free_area is larger than required. Shrink it.

Signed-off-by: Mel Gorman <mgorman@suse.de>
---
include/linux/mmzone.h | 9 +++++++--
mm/page_alloc.c | 23 +++++++++++++++++++----
2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index a6f84f1..ca04853 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -85,6 +85,11 @@ struct free_area {
unsigned long nr_free;
};

+struct free_area_magazine {
+ struct list_head free_list[MIGRATE_PCPTYPES];
+ unsigned long nr_free;
+};
+
struct pglist_data;

/*
@@ -365,8 +370,8 @@ struct zone {
* Keep some order-0 pages on a separate free list
* protected by an irq-unsafe lock
*/
- spinlock_t magazine_lock;
- struct free_area noirq_magazine;
+ spinlock_t magazine_lock;
+ struct free_area_magazine noirq_magazine;

#ifndef CONFIG_SPARSEMEM
/*
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9426174..79dfda7 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1100,7 +1100,7 @@ static
struct page *__rmqueue_magazine(struct zone *zone, int migratetype)
{
struct page *page;
- struct free_area *area = &(zone->noirq_magazine);
+ struct free_area_magazine *area = &(zone->noirq_magazine);

if (list_empty(&area->free_list[migratetype]))
return NULL;
@@ -1116,7 +1116,7 @@ struct page *__rmqueue_magazine(struct zone *zone, int migratetype)

static void magazine_drain(struct zone *zone, int migratetype)
{
- struct free_area *area = &(zone->noirq_magazine);
+ struct free_area_magazine *area = &(zone->noirq_magazine);
struct list_head *list;
struct page *page;
unsigned int batch_free = 0;
@@ -1183,12 +1183,27 @@ void free_hot_cold_page(struct page *page, bool cold)
{
struct zone *zone = page_zone(page);
int migratetype;
- struct free_area *area;
+ struct free_area_magazine *area;

if (!free_pages_prepare(page, 0))
return;

migratetype = get_pageblock_migratetype(page);
+
+ /*
+ * We only track unmovable, reclaimable and movable on magazines.
+ * 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
+ * excessively into the page allocator
+ */
+ if (migratetype >= MIGRATE_PCPTYPES) {
+ if (unlikely(is_migrate_isolate(migratetype))) {
+ free_one_page(zone, page, 0, migratetype);
+ return;
+ }
+ migratetype = MIGRATE_MOVABLE;
+ }
set_freepage_migratetype(page, migratetype);

/* magazine_lock is not safe against IRQs */
@@ -1334,7 +1349,7 @@ struct page *rmqueue_magazine(struct zone *zone, int migratetype)
if (!page) {
LIST_HEAD(alloc_list);
unsigned long flags;
- struct free_area *area = &(zone->noirq_magazine);
+ struct free_area_magazine *area = &(zone->noirq_magazine);
unsigned int i;
unsigned int nr_alloced = 0;

--
1.8.1.4