cma: fix counting of isolated pages

Isolated free pages shouldn't be accounted to NR_FREE_PAGES counter.  Fix
it by properly decreasing/increasing NR_FREE_PAGES counter in
set_migratetype_isolate()/unset_migratetype_isolate() and removing counter
adjustment for isolated pages from free_one_page() and split_free_page().

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a214abe436f9b5303e706c80e17e216afa5ed79e..2e403419a30c7b73a14ab90ba0022af906b9d475 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -690,7 +690,8 @@ static void free_one_page(struct zone *zone, struct page *page, int order,
        zone->pages_scanned = 0;
 
        __free_one_page(page, zone, order, migratetype);
-       __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
+       if (unlikely(migratetype != MIGRATE_ISOLATE))
+               __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
        spin_unlock(&zone->lock);
 }
 
@@ -1391,6 +1392,7 @@ int capture_free_page(struct page *page, int alloc_order, int migratetype)
        unsigned int order;
        unsigned long watermark;
        struct zone *zone;
+       int mt;
 
        BUG_ON(!PageBuddy(page));
 
@@ -1406,7 +1408,10 @@ int capture_free_page(struct page *page, int alloc_order, int migratetype)
        list_del(&page->lru);
        zone->free_area[order].nr_free--;
        rmv_page_order(page);
-       __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
+
+       mt = get_pageblock_migratetype(page);
+       if (unlikely(mt != MIGRATE_ISOLATE))
+               __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
 
        if (alloc_order != order)
                expand(zone, page, alloc_order, order,

diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 247d1f175739247718d087aee8bba3c810daaa46..3ca1716471bc5af48fef3560863b2c9e6bd15d60 100644 (file)
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -76,8 +76,12 @@ int set_migratetype_isolate(struct page *page)
 
 out:
        if (!ret) {
+               unsigned long nr_pages;
+
                set_pageblock_isolate(page);
-               move_freepages_block(zone, page, MIGRATE_ISOLATE);
+               nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE);
+
+               __mod_zone_page_state(zone, NR_FREE_PAGES, -nr_pages);
        }
 
        spin_unlock_irqrestore(&zone->lock, flags);
@@ -89,12 +93,14 @@ out:
 void unset_migratetype_isolate(struct page *page, unsigned migratetype)
 {
        struct zone *zone;
-       unsigned long flags;
+       unsigned long flags, nr_pages;
+
        zone = page_zone(page);
        spin_lock_irqsave(&zone->lock, flags);
        if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
                goto out;
-       move_freepages_block(zone, page, migratetype);
+       nr_pages = move_freepages_block(zone, page, migratetype);
+       __mod_zone_page_state(zone, NR_FREE_PAGES, nr_pages);
        restore_pageblock_isolate(page, migratetype);
 out:
        spin_unlock_irqrestore(&zone->lock, flags);