[RFC PATCH 5/7] vmscan: memcg: sleep when flushing stats during reclaim

[Yosry Ahmed]

Memory reclaim should be a sleepable context. Allow sleeping when
flushing memcg stats to avoid unnecessarily performing a lot of work
without sleeping. This can slow down reclaim code if flushing stats is
taking too long, but there is already multiple cond_resched()'s in
reclaim code.

Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
---
 mm/vmscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 59d1830d08ac..bae35cfb33c8 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2845,7 +2845,7 @@ static void prepare_scan_count(pg_data_t *pgdat, struct scan_control *sc)
 	 * Flush the memory cgroup stats, so that we read accurate per-memcg
 	 * lruvec stats for heuristics.
 	 */
-	mem_cgroup_flush_stats(false);
+	mem_cgroup_flush_stats(true);
 
 	/*
 	 * Determine the scan balance between anon and file LRUs.
-- 
2.40.0.rc1.284.g88254d51c5-goog