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From:   Huangzhaoyang <huangzhaoyang@gmail.com>
To:     Andrew Morton <akpm@linux-foundation.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Zhaoyang Huang <zhaoyang.huang@unisoc.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] mm: skip current when memcg reclaim
Date:   Fri, 15 Oct 2021 14:15:29 +0800
Message-Id: <1634278529-16983-1-git-send-email-huangzhaoyang@gmail.com>
Precedence: bulk

From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>

Sibling thread of the same process could refault the reclaimed pages
in the same time, which would be typical in None global reclaim and
introduce thrashing.
---
 mm/vmscan.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5199b96..ebbdc37 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2841,6 +2841,11 @@ static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc)
 				sc->memcg_low_skipped = 1;
 				continue;
 			}
+			/*
+			 * Don't bother current when its memcg is below low
+			 */
+			if (get_mem_cgroup_from_mm(current->mm) == memcg)
+				continue;
 			memcg_memory_event(memcg, MEMCG_LOW);
 		}
 
-- 
1.9.1