[PATCH 09/14] lru/swap: uer per lruvec lock in pagevec_lru_move_fn

[Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>]

to replace pgdat lru_lock.

Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
Cc: Peng Fan <peng.fan@xxxxxxx>
Cc: Nikolay Borisov <nborisov@xxxxxxxx>
Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: cgroups@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
 mm/swap.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/mm/swap.c b/mm/swap.c
index d2dad08fcfd0..24a2b3456e10 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -192,26 +192,27 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,
 	void *arg)
 {
 	int i;
-	struct pglist_data *pgdat = NULL;
-	struct lruvec *lruvec;
+	struct lruvec *locked_lruvec = NULL;
 	unsigned long flags = 0;
 
 	for (i = 0; i < pagevec_count(pvec); i++) {
 		struct page *page = pvec->pages[i];
-		struct pglist_data *pagepgdat = page_pgdat(page);
-
-		if (pagepgdat != pgdat) {
-			if (pgdat)
-				spin_unlock_irqrestore(&pgdat->lruvec.lru_lock, flags);
-			pgdat = pagepgdat;
-			spin_lock_irqsave(&pgdat->lruvec.lru_lock, flags);
+		struct pglist_data *pgdat = page_pgdat(page);
+		struct lruvec *lruvec = mem_cgroup_page_lruvec(page, pgdat);
+
+		if (locked_lruvec != lruvec) {
+			if (locked_lruvec)
+				spin_unlock_irqrestore(&locked_lruvec->lru_lock, flags);
+			locked_lruvec = lruvec;
+			spin_lock_irqsave(&lruvec->lru_lock, flags);
+			sync_lruvec_pgdat(lruvec, pgdat);
 		}
 
-		lruvec = mem_cgroup_page_lruvec(page, pgdat);
 		(*move_fn)(page, lruvec, arg);
 	}
-	if (pgdat)
-		spin_unlock_irqrestore(&pgdat->lruvec.lru_lock, flags);
+	if (locked_lruvec)
+		spin_unlock_irqrestore(&locked_lruvec->lru_lock, flags);
+
 	release_pages(pvec->pages, pvec->nr);
 	pagevec_reinit(pvec);
 }
-- 
1.8.3.1