[PATCH v4 2/4] mm: change PAGEREF_RECLAIM_CLEAN with PAGE_REFRECLAIM

[Minchan Kim]

The local variable references in shrink_page_list is PAGEREF_RECLAIM_CLEAN
as default. It is for preventing to reclaim dirty pages when CMA try to
migrate pages. Strictly speaking, we don't need it because CMA didn't allow
to write out by .may_writepage = 0 in reclaim_clean_pages_from_list.

Moreover, it has a problem to prevent anonymous pages's swap out even
though force_reclaim = true in shrink_page_list on upcoming patch.
So this patch makes references's default value to PAGEREF_RECLAIM and
rename force_reclaim with ignore_references to make it more clear.

This is a preparatory work for next patch.

* RFCv1
 * use ignore_referecnes as parameter name - hannes

Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
 mm/vmscan.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index a0301edd8d03..b4fa04d10ba6 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1119,7 +1119,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 				      struct scan_control *sc,
 				      enum ttu_flags ttu_flags,
 				      struct reclaim_stat *stat,
-				      bool force_reclaim)
+				      bool ignore_references)
 {
 	LIST_HEAD(ret_pages);
 	LIST_HEAD(free_pages);
@@ -1133,7 +1133,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 		struct address_space *mapping;
 		struct page *page;
 		int may_enter_fs;
-		enum page_references references = PAGEREF_RECLAIM_CLEAN;
+		enum page_references references = PAGEREF_RECLAIM;
 		bool dirty, writeback;
 		unsigned int nr_pages;
 
@@ -1264,7 +1264,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			}
 		}
 
-		if (!force_reclaim)
+		if (!ignore_references)
 			references = page_check_references(page, sc);
 
 		switch (references) {
-- 
2.22.0.410.gd8fdbe21b5-goog