[PATCH] mm/madvise: pageout under plugging

[Minchan Kim]

Likewise shrink_lruvec[1], madvise_pageout could get the benefit
from per-task block plug.

[1] 3da367c3e5fc, vmscan: add block plug for page reclaim
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
 mm/vmscan.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index fb9584641ac7..cf11113f6adb 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2556,6 +2556,7 @@ unsigned long reclaim_pages(struct list_head *page_list)
 	struct reclaim_stat dummy_stat;
 	struct page *page;
 	unsigned int noreclaim_flag;
+	struct blk_plug plug;
 	struct scan_control sc = {
 		.gfp_mask = GFP_KERNEL,
 		.may_writepage = 1,
@@ -2564,6 +2565,7 @@ unsigned long reclaim_pages(struct list_head *page_list)
 		.no_demotion = 1,
 	};
 
+	blk_start_plug(&plug);
 	noreclaim_flag = memalloc_noreclaim_save();
 
 	while (!list_empty(page_list)) {
@@ -2603,6 +2605,8 @@ unsigned long reclaim_pages(struct list_head *page_list)
 	}
 
 	memalloc_noreclaim_restore(noreclaim_flag);
+	blk_finish_plug(&plug);
+
 
 	return nr_reclaimed;
 }
-- 
2.34.1.173.g76aa8bc2d0-goog