From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CFA61C4451C for ; Sat, 18 Jul 2026 09:54:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D32296B00A0; Sat, 18 Jul 2026 05:54:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D08CF6B00A2; Sat, 18 Jul 2026 05:54:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C1F8A6B00A3; Sat, 18 Jul 2026 05:54:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 9E8406B00A0 for ; Sat, 18 Jul 2026 05:54:37 -0400 (EDT) Received: from smtpin05.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 31F5E1A0379 for ; Sat, 18 Jul 2026 09:54:37 +0000 (UTC) X-FDA: 85001437794.05.2B6AA8C Received: from out-187.mta1.migadu.com (out-187.mta1.migadu.com [95.215.58.187]) by imf01.hostedemail.com (Postfix) with ESMTP id 924B34000B for ; Sat, 18 Jul 2026 09:54:35 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=M7Vle5EV; spf=pass (imf01.hostedemail.com: domain of ridong.chen@linux.dev designates 95.215.58.187 as permitted sender) smtp.mailfrom=ridong.chen@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1784368475; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=lO66TrggiuQ7p/0nxBhsLlU4BVpMMd+j4O5LEqrNdrI=; b=f9UQFaTV7R9761OC28el8qRErnaTOx+K38gxeOCFD/GRXJ0r3azap5fNnRPnD00PH0s5sv fTC3+Canwg2QJyXGxB07B/cXkJOwnVhDIoI+4+eXzlcazZ/cupEOIRI8TihQbS1AehD7IV HOAZPvfGh10aUrBSzPfxjg78qQ/TcT8= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=M7Vle5EV; spf=pass (imf01.hostedemail.com: domain of ridong.chen@linux.dev designates 95.215.58.187 as permitted sender) smtp.mailfrom=ridong.chen@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1784368475; b=cTX/DbrX0null48gMks3dqo2nSqpZHKERFLP+STqDtywGHHMW92+NQsHUrpEisI3csecQI g0QBVAVweARtjdmuWZ9TaTPlM8A/gQYq0G+Dx5Emb+k7wiUmign+KsTPGrAYkgjqb1yxOV CfghfwPml5cdIzFyP9ceshGaGj335D8= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1784368474; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lO66TrggiuQ7p/0nxBhsLlU4BVpMMd+j4O5LEqrNdrI=; b=M7Vle5EV7fSyEDSoDc+ub+hZJ3XzmI8D08hPQ1s2AY4Zl02x7O6gHYGeqlsko18gRj5k9U IF4I4rqrl66FhbTOGVq5U8370Pr9XfmY3he+nMUypFBj2+o3+CBSqGulu8qQpPwkZtbEnk rdM+9yOjIv+BB9DYU2Xmz9HTphMUJgQ= From: Ridong Chen To: akpm@linux-foundation.org Cc: hannes@cmpxchg.org, david@kernel.org, mhocko@kernel.org, qi.zheng@linux.dev, shakeel.butt@linux.dev, ljs@kernel.org, kasong@tencent.com, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, hezhongkun.hzk@bytedance.com, muchun.song@linux.dev, dave@stgolabs.net, roman.gushchin@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, ridong.chen@linux.dev, Ridong Chen Subject: [PATCH v2 4/4] mm/mglru: fix anon-only reclaim evicting file pages when swappiness=max Date: Sat, 18 Jul 2026 17:52:51 +0800 Message-ID: <20260718095251.82937-5-ridong.chen@linux.dev> In-Reply-To: <20260718095251.82937-1-ridong.chen@linux.dev> References: <20260718095251.82937-1-ridong.chen@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 924B34000B X-Stat-Signature: gby4eqs5tw54howexgi43xraongu95pw X-HE-Tag: 1784368475-721416 X-HE-Meta: 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 VIe1xQqe Bou6548mjLpFbQl86Ucjr6tLV4DGOyUil9xERL24U1G71pz+6HbTwG8+kfnticZmeen3hGtF+mm0fHW07pk6SKcV3EfYyeOR3W6YzXjj8kYe40bkOWQTFHfaI51EW8UqCLDFiyH0zZEA+OhdrshfsPwP+QwCLP1ysvTm1sjwmdK7GLcQNeXhFH67i00okgcelPhB+Rva3D0k7L804Y1PXSWUrazUPEMM6sROGw02gw45zXHdZdPwZ3SaUz5l9AWy3nndcGa/18MbIcvvQENZyzeG9QJxmi8QPEkg8 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Ridong Chen The previous patch fixes this issue for the traditional LRU, which also exists in MGLRU [1]. Fix this by checking whether swappiness is SWAPPINESS_ANON_ONLY in get_swappiness() first, and returning 0 from get_nr_to_scan() when swappiness is SWAPPINESS_ANON_ONLY and anon pages cannot be reclaimed, to avoid useless work. The test result: Before fix: # cat /sys/kernel/mm/lru_gen/enabled 0x0007 # cat memory.stat anon 204800 file 67108864 ... pgsteal_proactive 0 pgscan_proactive 0 # echo "64M swappiness=max" > memory.reclaim # cat memory.stat anon 208896 file 0 ... pgsteal_proactive 16384 pgscan_proactive 16384 After fix: # cat memory.stat anon 188416 file 67215360 kernel 1970176 ... pgsteal_proactive 0 pgscan_proactive 0 # echo "64M swappiness=max" > memory.reclaim -bash: echo: write error: Resource temporarily unavailable # cat memory.stat anon 204800 file 67215360 ... pgsteal_proactive 0 pgscan_proactive 0 [1] https://sashiko.dev/#/patchset/20260717113300.214717-1-ridong.chen@linux.dev Fixes: 68a1436bde00 ("mm: add swappiness=max arg to memory.reclaim for only anon reclaim") Signed-off-by: Ridong Chen --- mm/vmscan.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index e1ef6350a300..240b04f0a21a 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2702,6 +2702,10 @@ static int get_swappiness(struct lruvec *lruvec, struct scan_control *sc) { struct mem_cgroup *memcg = lruvec_memcg(lruvec); struct pglist_data *pgdat = lruvec_pgdat(lruvec); + int swappiness = sc_swappiness(sc, memcg); + + if (swappiness == SWAPPINESS_ANON_ONLY) + return swappiness; if (!sc->may_swap) return 0; @@ -2710,7 +2714,7 @@ static int get_swappiness(struct lruvec *lruvec, struct scan_control *sc) mem_cgroup_get_nr_swap_pages(memcg) < MIN_LRU_BATCH) return 0; - return sc_swappiness(sc, memcg); + return swappiness; } static int get_nr_gens(struct lruvec *lruvec, int type) @@ -4915,6 +4919,14 @@ static long get_nr_to_scan(struct lruvec *lruvec, struct scan_control *sc, struct mem_cgroup *memcg, int swappiness) { unsigned long nr_to_scan, evictable; + struct pglist_data *pgdat = lruvec_pgdat(lruvec); + + /* Proactive reclaim: anon-only requested but anon is not reclaimable */ + if (swappiness == SWAPPINESS_ANON_ONLY && + !can_reclaim_anon_pages(memcg, pgdat->node_id, sc)) { + WARN_ON_ONCE(!sc->proactive); + return 0; + } evictable = lruvec_evictable_size(lruvec, swappiness); -- 2.43.0