From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794439644; b=5UtLzx2jCQB7IW1UVCwceQTy1To2JtdKWkboFYosCj3m9T1bxnHWZBknj9DR8ZBb+gdY bJEzX/UsUIOdNVgGSLKDJbg+NCq7XLDcsPk846yO6rJHJItGKLaHy1H3OsfMn6R2QkmsL hb7bcJVEe323peDGP8QLxK3A/n+67t+nQgipIe+1eWN1czqNfvzZ9bEIByaKKB8LbB6d2 r8veDiEqTAi79QDTKpj/j+XzOtec+YKPr1BAK3i/qCH5Z63pWlo+KIvykePUCmd9bngC+ 1HiF3u0d1glGax/VxPiCGk+XkS9rtr9ukVnZVRqYa+4/lLEF/M8l4l6avykvZ0NIhNQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794439644; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-Id:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=zlKFVUc+Cq7/iu4xyn5/uvDHqyvVKC45Z+ABVWfXn4I=; b=ixkHoBtzAI5Q1U3f52cP4aQjFK3kY/t2ey+j93olVGnfKvL59bPEL9JmWkoAPCh/4vRe PjoIZbmxWPhxeZv+UM2XojujR6jNO4vx/7dbbXf9QHIloBWbdsz6ndLtQ1guxGW6h1KsA euH3KIKGDPksbrusS8OH0oX6ULAZcKCEH+ZMeo4HOt0/hPl9uR9YYaVNVbT+oVWEdO9Sq A/DkFFdj8Ex2+qGXBYHyALWSMbtX79t79jFwIO8rnuNfKOmfE8BRW/5dC5FXs4TUwHFy9 7yp9WWaPwoT+zVnUpzFjipS62zR7GzyLclI+ccpTZcdV8mirig33umtQLaUN3qDpKTA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=JLi7dqh2; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 34F76606A332 for ; Wed, 11 Nov 2026 23:27:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=JLi7dqh2 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E3CD1F00A0B; Wed, 11 Nov 2026 23:27:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794439643; bh=zlKFVUc+Cq7/iu4xyn5/uvDHqyvVKC45Z+ABVWfXn4I=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JLi7dqh2JUvmWCHop4iEUWFNVgNnoLK6MUvtG2HxGhHLlK9eEjD2Ut/St51XS2ahX nUwltJLf3OmxE4+hXOl8YdKOa1Q7kkG4/eTPiMgfIVgWXWXyMP3ZXU18CLMG2WDtiC Sgl15FpuSMZfxH98ybz+j+yCYdsQeHjzGFOt473Q5nmHfDmKXAqLADmJ/SrzSX/INg roUjPVMTyXTyuEiKDhHvuCw7ygoDiFrngZKKucD29PfF1sOy7B/6diQRoThndGm9TP yXJ4gKmhkZ4kfNyXvoKeImIfNROgXEuKd1yarcBKRcRDKD16YQvGk7t56RIy6yYM2R CCkUJYcX++T8w== From: "Barry Song (Xiaomi)" To: akpm@linux-foundation.org Cc: axelrasmussen@google.com, baolin.wang@linux.alibaba.com, baoquan.he@linux.dev, hannes@cmpxchg.org, hui.zhu@linux.dev, kasong@tencent.com, kunwu.chan@gmail.com, liam@infradead.org, lianux.mm@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, liuxiang.277@bytedance.com, lyugaofei@xiaomi.com, mhocko@kernel.org, mhocko@suse.com, qi.zheng@linux.dev, ridong.chen@linux.dev, rppt@kernel.org, ryncsn@gmail.com, shakeel.butt@linux.dev, surenb@google.com, wangzicheng@honor.com, weixugc@google.com, yuanchu@google.com, zhangbo56@xiaomi.com, zhuhui@kylinos.cn, sidchintamaneni@gmail.com, Barry Song Subject: [PATCH v7 14/16] mm/mglru: Avoid prolonged anon reclaim with swappiness=200 Date: Thu, 12 Nov 2026 07:26:01 +0800 Message-Id: <20261111232603.9934-15-baohua@kernel.org> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20261111232603.9934-1-baohua@kernel.org> References: <20261111232603.9934-1-baohua@kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: lyugaofei It has been observed that swappiness=200 can significantly slow down reclaim on some machines, with some workloads running 3x slower under MGLRU than under CLRU. This is because swappiness=200 currently results in file_factor=0. Give file reclaim a small factor at lower priorities, for example, when sc->priority < DEF_PRIORITY / 2. Signed-off-by: lyugaofei Co-developed-by: Barry Song (Xiaomi) Signed-off-by: Barry Song (Xiaomi) --- mm/vmscan.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 6315edf50376..3872305bac2a 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4888,8 +4888,8 @@ static int get_tier_idx(struct lruvec *lruvec, int type) * We don't calculate the scan cost, MGLRU uses lazy promotion, which will * cancel the scan budget natually. */ -static void lru_gen_balance_scan(struct lruvec *lruvec, int swappiness, - unsigned long total_scan, unsigned long nr[]) +static void lru_gen_balance_scan(struct lruvec *lruvec, struct scan_control *sc, + int swappiness, unsigned long total_scan, unsigned long nr[]) { struct lru_gen_folio *lrugen = &lruvec->lrugen; u64 refault_rate[ANON_AND_FILE], anon_factor, file_factor; @@ -4946,7 +4946,12 @@ static void lru_gen_balance_scan(struct lruvec *lruvec, int swappiness, file_weight = nr[LRU_GEN_FILE] + nr[LRU_GEN_ANON] / size_bias; anon_factor = (u64)swappiness * refault_rate[LRU_GEN_FILE] * anon_weight; - file_factor = (u64)(MAX_SWAPPINESS - swappiness) * refault_rate[LRU_GEN_ANON] * file_weight; + if (swappiness == MAX_SWAPPINESS) + file_factor = sc->priority < DEF_PRIORITY / 2 ? + refault_rate[LRU_GEN_ANON] * file_weight : 0; + else + file_factor = (u64)(MAX_SWAPPINESS - swappiness) * + refault_rate[LRU_GEN_ANON] * file_weight; /* Cross-multiply the ratio above. */ anon_scan = mul_u64_u64_div_u64(total_scan, anon_factor, anon_factor + file_factor); @@ -5143,7 +5148,7 @@ static void lru_gen_prepare_scan(struct lruvec *lruvec, struct scan_control *sc, total = apply_proportional_protection(memcg, sc, total); total >>= sc->priority; - lru_gen_balance_scan(lruvec, swappiness, total, nr_to_scan); + lru_gen_balance_scan(lruvec, sc, swappiness, total, nr_to_scan); } static bool should_abort_scan(struct lruvec *lruvec, struct scan_control *sc) @@ -5890,7 +5895,7 @@ static int run_eviction(struct lruvec *lruvec, unsigned long seq, struct scan_co return 0; lruvec_evictable_size(lruvec, sc, swappiness, nr_to_scan); - lru_gen_balance_scan(lruvec, swappiness, + lru_gen_balance_scan(lruvec, sc, swappiness, nr_to_reclaim - sc->nr_reclaimed, nr_to_scan); if (!evict_folio_lists(nr_to_scan, lruvec, sc, swappiness, MAX_LRU_BATCH)) -- 2.34.1