mm: page_alloc: use get_freepage_migratetype() instead of page_private()

The page allocator uses set_page_private and page_private for handling
migratetype when it frees page.  Let's replace them with [set|get]
_freepage_migratetype to make it more clear.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 16 insertions, 4 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0d5f823ce3fc..4ed5c7367b9b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -237,6 +237,18 @@ struct inode;
 #define page_private(page)              ((page)->private)
 #define set_page_private(page, v)       ((page)->private = (v))
 
+/* It's valid only if the page is free path or free_list */
+static inline void set_freepage_migratetype(struct page *page, int migratetype)
+{
+        set_page_private(page, migratetype);
+}
+
+/* It's valid only if the page is free path or free_list */
+static inline int get_freepage_migratetype(struct page *page)
+{
+        return page_private(page);
+}
+
 /*
  * FIXME: take this include out, include page-flags.h in
  * files which need it (119 of them)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f2c7cc6a3039..6aa0a8e89c5d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -674,7 +674,7 @@ static void free_pcppages_bulk(struct zone *zone, int count,
                         page = list_entry(list->prev, struct page, lru);
                         /* must delete as __free_one_page list manipulates */
                         list_del(&page->lru);
-                        mt = page_private(page);
+                        mt = get_freepage_migratetype(page);
                         /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
                         __free_one_page(page, zone, 0, mt);
                         trace_mm_page_pcpu_drain(page, 0, mt);
@@ -1143,7 +1143,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
                         if (!is_migrate_cma(mt) && mt != MIGRATE_ISOLATE)
                                 mt = migratetype;
                 }
-                set_page_private(page, mt);
+                set_freepage_migratetype(page, mt);
                 list = &page->lru;
                 if (is_migrate_cma(mt))
                         __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
@@ -1313,7 +1313,7 @@ void free_hot_cold_page(struct page *page, int cold)
                 return;
 
         migratetype = get_pageblock_migratetype(page);
-        set_page_private(page, migratetype);
+        set_freepage_migratetype(page, migratetype);
         local_irq_save(flags);
         if (unlikely(wasMlocked))
                 free_page_mlock(page);
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 345643b85bd4..9c03dca8c2ad 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -203,7 +203,7 @@ __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn)
                 if (PageBuddy(page))
                         pfn += 1 << page_order(page);
                 else if (page_count(page) == 0 &&
-                                page_private(page) == MIGRATE_ISOLATE)
+                        get_freepage_migratetype(page) == MIGRATE_ISOLATE)
                         pfn += 1;
                 else
                         break;