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 8D24EC4452B for ; Thu, 23 Jul 2026 03:25:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 736166B00C6; Wed, 22 Jul 2026 23:25:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 70E126B00C7; Wed, 22 Jul 2026 23:25:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 600C36B00C8; Wed, 22 Jul 2026 23:25:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 33AAD6B00C6 for ; Wed, 22 Jul 2026 23:25:13 -0400 (EDT) Received: from smtpin19.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id A752F140361 for ; Thu, 23 Jul 2026 03:25:12 +0000 (UTC) X-FDA: 85018600464.19.BCA6B50 Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) by imf11.hostedemail.com (Postfix) with ESMTP id 0D15F40006 for ; Thu, 23 Jul 2026 03:25:10 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=dWO4NxvV; spf=pass (imf11.hostedemail.com: domain of ridong.chen@linux.dev designates 91.218.175.188 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=1784777111; 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=Z8OTpiatQBHFhVb1kcbCtXbO04T0mIjzVEpsj33f5I8=; b=C/S8TgJImI47JOm9EN1WabJEap8NyebYBAaUrrodoW/+tz3rS+zUtVkfslRVTXhIeN3Tr4 lXBlAj4nOD600qcErQK1oJj/WQUSXpNezGuAnC/ptyr86kKh0VAH9VUAd+Klnd9HAZVlAm 1V2dW2zAUnL0hmK6QjSc+sVS8hiNnlw= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=dWO4NxvV; spf=pass (imf11.hostedemail.com: domain of ridong.chen@linux.dev designates 91.218.175.188 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=1784777111; b=g4MaOWGb953bTIiGUqyhYten/8BPAwROkDSF7+6/2O7nxjUrZNAFCAXhaEdLdoF/Hc2/X0 K+ILFngsnhYHgazkflSrxijShNEqAKOR+gT0ETdLBaskDXMB5tJcJee7FSq4jWIChBJcjS 45ly4zYB766/QudgZkbjNn+A+GWr1wg= 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=1784777108; 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=Z8OTpiatQBHFhVb1kcbCtXbO04T0mIjzVEpsj33f5I8=; b=dWO4NxvVnnjKGuqo3qzfxKzhUKo3sdjpaWPlrGNi6aOGIcZXw0WenQYF3Vs1M4OTZnArqC 9lcjRkm8zXCLDuvZf21/B6QEXLG3RPuuStjDBl8rvOEnAtYypC/wemgFHFpjWvOOdV8Q2Q nNrovUKOq8dYSrn4gT/RZduAGdwZCZo= From: Ridong To: Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Andrew Morton , Chris Li , Kairui Song Cc: Muchun Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Youngjun Park , David Hildenbrand , Qi Zheng , Lorenzo Stoakes , Axel Rasmussen , Yuanchu Xie , Wei Xu , Davidlohr Bueso , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Song Hu , Ridong Chen , Ridong Chen , stable@vger.kernel.org Subject: [PATCH -v4 2/2] mm: vmscan: fix node reclaim ignoring swappiness parameter Date: Thu, 23 Jul 2026 11:24:34 +0800 Message-Id: <20260723032434.2016749-3-ridong.chen@linux.dev> In-Reply-To: <20260723032434.2016749-1-ridong.chen@linux.dev> References: <20260723032434.2016749-1-ridong.chen@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 0D15F40006 X-Stat-Signature: pai9r9nyh7qoko3x8qpanuy558yss7h7 X-HE-Tag: 1784777110-933444 X-HE-Meta: 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 jf3s//CO Sre/GF3YueCDA0iVrmgvs2K8YzyY14Xum8BSWZsbk0WGPprItnfCwVChpyPIZZZqb/jlpz9/1AEJYuhLa5CyRnKM1QXD7I45uIlc8jI0jGJ9PUmIc+9xGpSqtLc+ssyHlw39RlbqU0Ou+uCUF5yINbtG969cfnFWkfva5p8lTdqvoMioSxUPf48MjhPwsrpF8LBI6dC0azVo7StCGf+6cY4nW0M9KftwL8bR/KR32jrejP0oefAd0C1hD7F9RUrAjswG4uk0SSP+anOiI6BpNyS7Xn/RosMFH6UBRH8Nd8EBsuAtTv5HKiJ36OQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Ridong Chen sc_swappiness() had two separate definitions depending on CONFIG_MEMCG. The !CONFIG_MEMCG variant simply returned vm_swappiness, ignoring the proactive_swappiness value passed through scan_control. This caused the swappiness parameter written to /sys/devices/system/node/nodeX/reclaim to have no effect when CONFIG_MEMCG is disabled. Fix this by consolidating sc_swappiness() into a single definition that checks sc->proactive_swappiness first, then falls back to mem_cgroup_swappiness() which already handles both CONFIG_MEMCG and !CONFIG_MEMCG. Before fix (swappiness=max ignored, mostly file pages reclaimed): # cat /proc/sys/vm/swappiness 60 # cat /proc/vmstat | grep pgsteal pgsteal_kswapd 0 pgsteal_direct 0 pgsteal_khugepaged 0 pgsteal_proactive 1840 pgsteal_anon 25 pgsteal_file 1815 # echo "64M swappiness=max" > /sys/devices/system/node/node0/reclaim # cat /proc/vmstat | grep pgsteal pgsteal_kswapd 0 pgsteal_direct 0 pgsteal_khugepaged 0 pgsteal_proactive 18013 pgsteal_anon 337 pgsteal_file 17676 After fix (swappiness=max honored, anon pages reclaimed as expected): # cat /proc/vmstat | grep pgsteal pgsteal_kswapd 0 pgsteal_direct 0 pgsteal_khugepaged 0 pgsteal_proactive 0 pgsteal_anon 0 pgsteal_file 0 # echo "64M swappiness=max" > /sys/devices/system/node/node0/reclaim # cat /proc/vmstat | grep pgsteal pgsteal_kswapd 0 pgsteal_direct 0 pgsteal_khugepaged 0 pgsteal_proactive 16283 pgsteal_anon 16283 pgsteal_file 0 Cc: stable@vger.kernel.org # 6.17+ Fixes: b980077899ea ("mm: introduce per-node proactive reclaim interface") Acked-by: Johannes Weiner Reviewed-by: Barry Song Acked-by: Qi Zheng Tested-by: Song Hu Reviewed-by: Song Hu Signed-off-by: Ridong Chen --- mm/vmscan.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 06e103f9781e..155167b3614b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -199,6 +199,13 @@ struct scan_control { */ int vm_swappiness = 60; +static int sc_swappiness(struct scan_control *sc, struct mem_cgroup *memcg) +{ + if (sc->proactive && sc->proactive_swappiness) + return *sc->proactive_swappiness; + return mem_cgroup_swappiness(memcg); +} + #ifdef CONFIG_MEMCG /* Returns true for reclaim through cgroup limits or cgroup interfaces. */ @@ -239,13 +246,6 @@ static bool writeback_throttling_sane(struct scan_control *sc) #endif return false; } - -static int sc_swappiness(struct scan_control *sc, struct mem_cgroup *memcg) -{ - if (sc->proactive && sc->proactive_swappiness) - return *sc->proactive_swappiness; - return mem_cgroup_swappiness(memcg); -} #else static bool cgroup_reclaim(struct scan_control *sc) { @@ -261,11 +261,6 @@ static bool writeback_throttling_sane(struct scan_control *sc) { return true; } - -static int sc_swappiness(struct scan_control *sc, struct mem_cgroup *memcg) -{ - return READ_ONCE(vm_swappiness); -} #endif static void set_task_reclaim_state(struct task_struct *task, -- 2.34.1