[RFC] mm/compaction: ignore block suitable after check large free page

From: Yisheng Xie
Date: Thu Mar 09 2017 - 23:25:24 EST


If the migrate target is a large free page and we ignore suitable,
it may not good for defrag. So move the ignore block suitable after
check large free page.

Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
---
mm/compaction.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index 0fdfde0..4bf2a5d 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -991,9 +991,6 @@ static bool too_many_isolated(struct zone *zone)
static bool suitable_migration_target(struct compact_control *cc,
struct page *page)
{
- if (cc->ignore_block_suitable)
- return true;
-
/* If the page is a large free page, then disallow migration */
if (PageBuddy(page)) {
/*
@@ -1005,6 +1002,9 @@ static bool suitable_migration_target(struct compact_control *cc,
return false;
}

+ if (cc->ignore_block_suitable)
+ return true;
+
/* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */
if (migrate_async_suitable(get_pageblock_migratetype(page)))
return true;
--
1.7.12.4