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=1794439654; b=e1ZwFN8VrvsTYblWqruZB29Xt8BIFX3oZzKYlljzQiXdMXNJEp1J50lmfPuOyHOn9cKj x6JnQX8XEm8W63Sb+4EDlsS6LR9+xI0+Snm0kpvvlLnShlIf7xO3DmGUbt5x/vzMoLxYK 705r+x15qnlS408qF0r2s+BRk1icp6ncJyZ4A8H1QAGCD/0/JmVmeEbEP2RLViybQVXS8 G2KNQQsUqB9bNKZF04CD/zmkgUajCKF8ZXlnjiEHx+bcktnnyWpCKc5E+ndnDY/gqeSkU L7XHlOgDJfu5sZcdq01BBP00PQy+3CWwt0MUJVSYWL8LuEv25beuLSLsKDik51kxUqQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794439654; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-Id:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=mzO4KiqZw719W+0CmuqrZxCm8Y3trZUlrMTybnCiAns=; b=L59bON8yVggvKU+kCdAuozP6Etvg82iv2lZUlnAYFZD90bxUnLX1ZMySUztPd7a3HBF7 ck5GFyLbn/2YImPAVN20vBDLDIUgfHJYNoA7Fo1+By1jrmVizbcrDXLEKtLcQ75e/RcRP jkb3cEQx7zkPo18cYr/bvAzRDkW4tI/GK8/DZXQ5s52y1qu9S/avHYr4X0Z8VVpZp2uOE P+8IOyyYPsPmiycP/oqriKpMMgJCEBFpqNoJ7JN6UuPP0VSHlnYBtaqURBdqXFBuPznS3 QaPMVJC5ad6t+hcqXd1/9bobGvzOUObkw/rU8ZcaF4owRBMqB/ZA4SiaahmwPWABR4Q== 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=Iq2EVakL; 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 A989E60A263B for ; Wed, 11 Nov 2026 23:27:34 +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=Iq2EVakL Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68EBC1F00A08; Wed, 11 Nov 2026 23:27:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794439654; bh=mzO4KiqZw719W+0CmuqrZxCm8Y3trZUlrMTybnCiAns=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Iq2EVakL0MhzMjJN/wPKDl5O+vbqbX16HeJU7+ZbRzhfWqhoFz5ZKXQZvz1w+T1Dh KF7kUlO4GnmYu/rJ9WBO037T2whfizPK9qfARINQmf/WU+uE6o0mdUJgDhsrdsk2BD +vHXCGDZnWUr0SHJUYqthnjYoc4qrGHzxTy7vAulu7g6xadWDlyp31AZdJmuGSmTE1 /VjiXN4BZwD5AbUWu/lxEOyAX8SquKAvnqDbEgXviM3t0XTihH2dIDWoxZh3hyUze/ NIQwLPCscGRMe4sfAGPYo/XEB9VF4W1tuxytr5WtLdmJ/FrEtnrRTwCRP37zrXP3VE x7W+68/cOUQcg== 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 , Kunwu Chan Subject: [PATCH v7 16/16] mm/mglru: Avoid scan anon while swapcache is low for GFP_NOIO allocation Date: Thu, 12 Nov 2026 07:26:03 +0800 Message-Id: <20261111232603.9934-17-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: Bo Zhang With GFP_NOIO, we cannot reclaim anon folios unless they are in the swap cache. CLRU skips anon reclaim when the swap cache is very low by commit 74d9aa0d8e98 ("mm: vmscan: avoid anon scanning for GFP_NOIO with low swapcache"). Apply the same logic to MGLRU. The new scan-budget-based mechanism makes this straightforward to implement. Thanks also to Xiang Liu, who previously attempted to fix this before we had the scan-budget-based model [1]. [1] https://lore.kernel.org/linux-mm/179248830836.1744016.8424217811286616919.noio-mglru-rfc-v2@bytedance.com/ Cc: Xiang Liu Signed-off-by: Bo Zhang Co-developed-by: Barry Song (Xiaomi) Signed-off-by: Barry Song (Xiaomi) Reviewed-by: Kunwu Chan --- mm/vmscan.c | 27 ++++++++++----------------- 1 file changed, 10 insertions(+), 17 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index d51303a5cb67..9f759d213614 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -272,13 +272,6 @@ static inline bool reclaimable_anon_is_low(struct mem_cgroup *memcg, if (!sc || (sc->gfp_mask & __GFP_IO)) return false; - /* - * FIXME: MGLRU doesn't fully respect can_reclaim_anon_pages() for the - * scanning type, so only apply this to the traditional LRU for now. - */ - if (lru_gen_enabled()) - return false; - if (memcg) { struct lruvec *lruvec = mem_cgroup_lruvec(memcg, pgdat); @@ -4212,6 +4205,8 @@ static void lruvec_evictable_size(struct lruvec *lruvec, struct scan_control *sc int type; unsigned long seq; struct lru_gen_folio *lrugen = &lruvec->lrugen; + struct mem_cgroup *memcg = lruvec_memcg(lruvec); + int nid = lruvec_pgdat(lruvec)->node_id; DEFINE_MAX_SEQ(lruvec); DEFINE_MIN_SEQ(lruvec); @@ -4219,6 +4214,8 @@ static void lruvec_evictable_size(struct lruvec *lruvec, struct scan_control *sc nr[LRU_GEN_FILE] = 0; for_each_evictable_type(type, swappiness) { + if (type == LRU_GEN_ANON && !can_reclaim_anon_pages(memcg, nid, sc)) + continue; for (seq = min_seq[type]; seq <= max_seq; seq++) nr[type] += lruvec_gen_size(lrugen, type, seq, sc->reclaim_idx + 1); } @@ -4893,23 +4890,19 @@ static void lru_gen_balance_scan(struct lruvec *lruvec, struct scan_control *sc, { struct lru_gen_folio *lrugen = &lruvec->lrugen; u64 refault_rate[ANON_AND_FILE], anon_factor, file_factor; - u64 anon_scan, file_scan, total; + u64 anon_scan, file_scan; u64 anon_weight, file_weight; int size_bias; - total = nr[LRU_GEN_ANON] + nr[LRU_GEN_FILE]; - if (!total) - return; - - if (swappiness <= MIN_SWAPPINESS) { + if (swappiness <= MIN_SWAPPINESS) nr[LRU_GEN_ANON] = 0; - nr[LRU_GEN_FILE] = min_t(u64, total_scan, nr[LRU_GEN_FILE]); - return; - } - if (swappiness == SWAPPINESS_ANON_ONLY) { + if (swappiness == SWAPPINESS_ANON_ONLY) nr[LRU_GEN_FILE] = 0; + + if (!nr[LRU_GEN_ANON] || !nr[LRU_GEN_FILE]) { nr[LRU_GEN_ANON] = min_t(u64, total_scan, nr[LRU_GEN_ANON]); + nr[LRU_GEN_FILE] = min_t(u64, total_scan, nr[LRU_GEN_FILE]); return; } -- 2.34.1