[RFC 1/4] mm, compaction: change migrate_async_suitable() to suitable_migration_source()

From: Vlastimil Babka
Date: Thu Sep 29 2016 - 17:06:40 EST


Preparation for making the decisions more complex and depending on
compact_control flags. No functional change.

Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
---
include/linux/mmzone.h | 5 +++++
mm/compaction.c | 19 +++++++++++--------
2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 454495cc00fe..9cd3ee58ab2b 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -72,6 +72,11 @@ extern char * const migratetype_names[MIGRATE_TYPES];
# define is_migrate_cma(migratetype) false
#endif

+static inline bool is_migrate_movable(int mt)
+{
+ return is_migrate_cma(mt) || mt == MIGRATE_MOVABLE;
+}
+
#define for_each_migratetype_order(order, type) \
for (order = 0; order < MAX_ORDER; order++) \
for (type = 0; type < MIGRATE_TYPES; type++)
diff --git a/mm/compaction.c b/mm/compaction.c
index 6e77b2016da1..673a81618534 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -88,11 +88,6 @@ static void map_pages(struct list_head *list)
list_splice(&tmp_list, list);
}

-static inline bool migrate_async_suitable(int migratetype)
-{
- return is_migrate_cma(migratetype) || migratetype == MIGRATE_MOVABLE;
-}
-
#ifdef CONFIG_COMPACTION

int PageMovable(struct page *page)
@@ -996,6 +991,15 @@ isolate_migratepages_range(struct compact_control *cc, unsigned long start_pfn,
#endif /* CONFIG_COMPACTION || CONFIG_CMA */
#ifdef CONFIG_COMPACTION

+static bool suitable_migration_source(struct compact_control *cc,
+ struct page *page)
+{
+ if (cc->mode != MIGRATE_ASYNC)
+ return true;
+
+ return is_migrate_movable(get_pageblock_migratetype(page));
+}
+
/* Returns true if the page is within a block suitable for migration to */
static bool suitable_migration_target(struct compact_control *cc,
struct page *page)
@@ -1015,7 +1019,7 @@ static bool suitable_migration_target(struct compact_control *cc,
}

/* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */
- if (migrate_async_suitable(get_pageblock_migratetype(page)))
+ if (is_migrate_movable(get_pageblock_migratetype(page)))
return true;

/* Otherwise skip the block */
@@ -1250,8 +1254,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
* Async compaction is optimistic to see if the minimum amount
* of work satisfies the allocation.
*/
- if (cc->mode == MIGRATE_ASYNC &&
- !migrate_async_suitable(get_pageblock_migratetype(page)))
+ if (!suitable_migration_source(cc, page))
continue;

/* Perform the isolation */
--
2.10.0