[PATCH] mm: avoid the unnecessary waiting when force empty a cgroup
From: Li RongQing
Date: Tue Apr 03 2018 - 03:12:38 EST
The number of writeback and dirty page can be read out from memcg,
the unnecessary waiting can be avoided by these counts
Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx>
---
mm/memcontrol.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9ec024b862ac..5258651bd4ec 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2613,9 +2613,13 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
progress = try_to_free_mem_cgroup_pages(memcg, 1,
GFP_KERNEL, true);
if (!progress) {
+ unsigned long num;
+
+ num = memcg_page_state(memcg, NR_WRITEBACK) +
+ memcg_page_state(memcg, NR_FILE_DIRTY);
nr_retries--;
- /* maybe some writeback is necessary */
- congestion_wait(BLK_RW_ASYNC, HZ/10);
+ if (num)
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
}
}
--
2.11.0