[PATCH RFC 1/4] mm/page_alloc: convert "report" flag of __free_one_page() to a proper flag

[David Hildenbrand]

Let's prepare for additional flags and avoid long parameter lists of bools.
Follow-up patches will also make use of the flags in __free_pages_ok(),
however, I wasn't able to come up with a better name for the type - should
be good enough for internal purposes.

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
 mm/page_alloc.c | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6b699d273d6e..91cefb8157dd 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -77,6 +77,18 @@
 #include "shuffle.h"
 #include "page_reporting.h"
 
+/* Free One Page flags: for internal, non-pcp variants of free_pages(). */
+typedef int __bitwise fop_t;
+
+/* No special request */
+#define FOP_NONE		((__force fop_t)0)
+
+/*
+ * Skip free page reporting notification after buddy merging (will *not* mark
+ * the page reported, only skip the notification).
+ */
+#define FOP_SKIP_REPORT_NOTIFY	((__force fop_t)BIT(0))
+
 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
 static DEFINE_MUTEX(pcp_batch_high_lock);
 #define MIN_PERCPU_PAGELIST_FRACTION	(8)
@@ -948,10 +960,9 @@ buddy_merge_likely(unsigned long pfn, unsigned long buddy_pfn,
  * -- nyc
  */
 
-static inline void __free_one_page(struct page *page,
-		unsigned long pfn,
-		struct zone *zone, unsigned int order,
-		int migratetype, bool report)
+static inline void __free_one_page(struct page *page, unsigned long pfn,
+				   struct zone *zone, unsigned int order,
+				   int migratetype, fop_t fop_flags)
 {
 	struct capture_control *capc = task_capc(zone);
 	unsigned long buddy_pfn;
@@ -1038,7 +1049,7 @@ static inline void __free_one_page(struct page *page,
 		add_to_free_list(page, zone, order, migratetype);
 
 	/* Notify page reporting subsystem of freed page */
-	if (report)
+	if (!(fop_flags & FOP_SKIP_REPORT_NOTIFY))
 		page_reporting_notify_free(order);
 }
 
@@ -1368,7 +1379,7 @@ static void free_pcppages_bulk(struct zone *zone, int count,
 		if (unlikely(isolated_pageblocks))
 			mt = get_pageblock_migratetype(page);
 
-		__free_one_page(page, page_to_pfn(page), zone, 0, mt, true);
+		__free_one_page(page, page_to_pfn(page), zone, 0, mt, FOP_NONE);
 		trace_mm_page_pcpu_drain(page, 0, mt);
 	}
 	spin_unlock(&zone->lock);
@@ -1384,7 +1395,7 @@ static void free_one_page(struct zone *zone,
 		is_migrate_isolate(migratetype))) {
 		migratetype = get_pfnblock_migratetype(page, pfn);
 	}
-	__free_one_page(page, pfn, zone, order, migratetype, true);
+	__free_one_page(page, pfn, zone, order, migratetype, FOP_NONE);
 	spin_unlock(&zone->lock);
 }
 
@@ -3277,7 +3288,8 @@ void __putback_isolated_page(struct page *page, unsigned int order, int mt)
 	lockdep_assert_held(&zone->lock);
 
 	/* Return isolated page to tail of freelist. */
-	__free_one_page(page, page_to_pfn(page), zone, order, mt, false);
+	__free_one_page(page, page_to_pfn(page), zone, order, mt,
+			FOP_SKIP_REPORT_NOTIFY);
 }
 
 /*
-- 
2.26.2