From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1214736F421; Fri, 4 Sep 2026 05:09:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788498563; cv=none; b=kXDIES2cq7hDoXFcH9eab2ja4ii2mBLqO4AecP8COHcvUj9JKgFoEAdFe6B1qfRmKK+E0ugZnyugdWgNw/81p9BMBU7vua/z5+IZUcWs5Z3g6HWnxzgEBXI7Yl7x8N2NqkLWibYty9nRiEjFrCYXsvBcdWA9nx7UseHFLwhZwSE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788498563; c=relaxed/simple; bh=7Jj3VFD6a0PbWEVzsiBQOm9aXlhr9aNOmjnq2W+1erA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=alt66vQJnrK6edJpqSp4p5JFRKKUHmGCfXFKOtgR2dAwCSOA6Vg+4HSA+GUJrOGJqKKf6gUFtRWp2QnZkTJNn7eCCjqP9aaRMKrYDqG6zfGcGThXUxkLDPOz4PBa8Gk47wJ/RnfTyMER0bjF0zoPlJdkNyyEi3BZ7kO8lgSPNFA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Mu3pRtU0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Mu3pRtU0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 482641F00A3D; Fri, 4 Sep 2026 05:09:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788498562; bh=07QlXB6cSqMnaaQ8yNdNQ3T+6g9fhuWwKMm91N8HjtM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Mu3pRtU0N0qss6O5TSF7l3vPAoReRURYqAHTtUVm2JYx8NjR24zYIDhDE2S6vfA+z YTU37YT+hIT8P0Y3Za02QSurx+IZ7axtaM73yTSBe0jlc0L41E9Z4f6/0nHDnOBDwa Zcel5sAsNpO/XvP1QGuZ2Jm6idD91iJsaNMoS+jY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ridong Chen , Johannes Weiner , Barry Song , Qi Zheng , Song Hu , Shakeel Butt , Axel Rasmussen , Baoquan He , Chris Li , David Hildenbrand , Davidlohr Bueso , Kairui Song , Kemeng Shi , Lorenzo Stoakes , Michal Hocko , Muchun Song , Nhat Pham , Roman Gushchin , Wei Xu , Yuanchu Xie , Andrew Morton Subject: [PATCH 7.2 080/713] mm: vmscan: fix node reclaim ignoring swappiness parameter Date: Fri, 4 Sep 2026 06:50:48 +0200 Message-ID: <20260904045805.633689406@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045803.810145556@linuxfoundation.org> References: <20260904045803.810145556@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ridong Chen commit 8a905195850d383c0465ab5bdd3c91d94269b242 upstream. 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 Link: https://lore.kernel.org/20260723032434.2016749-3-ridong.chen@linux.dev Fixes: b980077899ea ("mm: introduce per-node proactive reclaim interface") Signed-off-by: Ridong Chen Acked-by: Johannes Weiner Reviewed-by: Barry Song Acked-by: Qi Zheng Tested-by: Song Hu Reviewed-by: Song Hu Acked-by: Shakeel Butt Cc: Axel Rasmussen Cc: Baoquan He Cc: Chris Li Cc: David Hildenbrand Cc: Davidlohr Bueso Cc: Kairui Song Cc: Kemeng Shi Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Muchun Song Cc: Nhat Pham Cc: Roman Gushchin Cc: Wei Xu Cc: Yuanchu Xie Cc: [6.17+] Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/vmscan.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -198,6 +198,13 @@ 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. */ @@ -238,13 +245,6 @@ static bool writeback_throttling_sane(st #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) { @@ -260,11 +260,6 @@ static bool writeback_throttling_sane(st { 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,