[PATCH v1 8/9] vmscan: memcg: sleep when flushing stats during reclaim

From: Yosry Ahmed <yosryahmed@google.com>
To: "Tejun Heo" <tj@kernel.org>, "Josef Bacik" <josef@toxicpanda.com>,
	"Jens Axboe" <axboe@kernel.dk>,
	"Zefan Li" <lizefan.x@bytedance.com>,
	"Johannes Weiner" <hannes@cmpxchg.org>,
	"Michal Hocko" <mhocko@kernel.org>,
	"Roman Gushchin" <roman.gushchin@linux.dev>,
	"Shakeel Butt" <shakeelb@google.com>,
	"Muchun Song" <muchun.song@linux.dev>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Michal Koutný" <mkoutny@suse.com>
Cc: Vasily Averin <vasily.averin@linux.dev>,
	cgroups@vger.kernel.org, linux-block@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	bpf@vger.kernel.org, Yosry Ahmed <yosryahmed@google.com>
Subject: [PATCH v1 8/9] vmscan: memcg: sleep when flushing stats during reclaim
Date: Tue, 28 Mar 2023 06:16:37 +0000	[thread overview]
Message-ID: <20230328061638.203420-9-yosryahmed@google.com> (raw)
In-Reply-To: <20230328061638.203420-1-yosryahmed@google.com>

Memory reclaim is 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@google.com>
---
 mm/vmscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index a9511ccb936f..9c1c5e8b24b8 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_atomic();
+	mem_cgroup_flush_stats();
 
 	/*
 	 * Determine the scan balance between anon and file LRUs.
-- 
2.40.0.348.gf938b09366-goog

