From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f170.google.com (mail-qk1-f170.google.com [209.85.222.170]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C50AC48035B for ; Mon, 20 Jul 2026 19:35:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784576127; cv=none; b=HdQzAaMDgoOghFkYOWcauu2zhJXALzz4E16wR84kvkRtJpkLJYfVsIdrjyv/0QY7EEaWLroTd1ag5D8B+Sum/cmXpRCOIOcRuScp17DMlWCKn982fludFyNu6M29yMBOE2C35DEH28yBYlo8KEL3V1dLDR/YI9sdWV1SQ8SUGvA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784576127; c=relaxed/simple; bh=AclVB29m5XEXwT6jfLm+y0Vje/ATQlFgKmkw+sbjY3Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SO4Zl/qJrYGbqbibQZ3SKJEM21YIjX8/vKqQe9EJxMoqE5e5AA/fpFAq90aLZsfnHr4PK87hxN3trxAPUtlrR2aemsRMCXjtoPwu4KYNM5ovaLad38KTkB/FyWRHb8vYA00eUPZonimDhLq7sfeDXi/0PvaJ8XoBGgA7mTfjd7w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net; spf=pass smtp.mailfrom=gourry.net; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b=KTYLBPs3; arc=none smtp.client-ip=209.85.222.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gourry.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b="KTYLBPs3" Received: by mail-qk1-f170.google.com with SMTP id af79cd13be357-92e533aacf2so395281185a.2 for ; Mon, 20 Jul 2026 12:35:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1784576123; x=1785180923; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=v2LDhxlVOpgNtSXDCdv8imM0ubGsvF9EJ4oiPoX2j2c=; b=KTYLBPs3dWcRB5tNY5Y315YJNYwSMrSW38ozrn7zBlvcl5Bgj0pNovXwYuhmdviEr6 vGvh5Tm6m6ydUQi82zIG49v7mWgnbI4X0h3X9mabjFu39jmqmc0ad6N6+0VTgyeMRySg U67Thqs1ToMZc0ZR+8TgO8LsSqcKGdmBEkEQHgfrraLsi0CXj8Ba77QZxDY5AKvlIRFi 6q/dihXzF+eQ9FAgtleDsSd4cK5HY0uc5r/y6rh1gmcA1PS8AAV7YHcb3xRC5QQMheCa vFx1oCPPO8nV4G83ZDlOcBlYxLNa8TfGyggXhkeXkCtRXY8EycNoBEI8uEixfJ4mDjdy lU1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784576123; x=1785180923; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=v2LDhxlVOpgNtSXDCdv8imM0ubGsvF9EJ4oiPoX2j2c=; b=jKGxGxXKV6xs3aDRWo8UB8I2NVbZLFaPBN/BHUKAul3Ta2XA3Unbl23hfw4ifRk+HK YtyWJASq6X42aXdwDHc5PJN8rSHFusFsVVEfxSEcNdIejNbicQ1spzNhT5AqMis2OVkK PbZ1nyeY6bHncomZNfU5DGx9DGg/5U2kof3eXptEydR/MJeJkugtl/Bmco6s/dA6Y6pO TQDSPhpk3clzBS27lrtaKfdaFFFG8l+NqUc2AdsWf7w6TjgtEbuBgQByzSfBopz/j8J7 zybgbf6p+iboy7l6XUhZVJyGVI0G3lRNEnpAl0Zl3HWkn43ygM8gGg/G1WUBmiefmtnn bb7w== X-Forwarded-Encrypted: i=1; AHgh+RpF2jH98CmMpUe3iqiM1eUmz3x7IexdXX0PIkntQ92W6kKkySiCymNVw4LA5yOJYFCYzCW/IGbBqvo=@vger.kernel.org X-Gm-Message-State: AOJu0Yz/WIP5F14IXB4OyTQtrpEfX/aSgsQw6xUh0dPJlXVVOYRmNcpG rd/h37FD0WrfSdllLv5gv9sXBVHDU3RTvYLNa6oK5QjWSZVSSgwTyU437nEHi+jJtXo= X-Gm-Gg: AfdE7clpwvqw2fIRgGhFMXjnJc2pRWP/8nXvU80knLSkYS/QnklfZ3WdqSDopuoqQGr HfHncJnjdP7az19S0y8a6XD2j0hBjnrPfuM1kNhXYXWM4IETzI6V882Fvl73SzFgtKLkCy3KvRs tHKFOMpfdH9Ug3lI8MixXg0O4kH9jNfuFZpdt0Wj7czN5722tDsFjUMbjpLSJBi6sVv9NZpGMoq eBNX46XTumvDW3GlvzHyj68AR6mSPw6Jnrr8BHB0sL0Xrimu2hND+Za26xgsfM9lxsozEJP+qzW r1iLcMibXsKB1+1xr4FYAyPorO+VRn3alPcZCJP3/gSRE3Llyk23CyrlTpG89T4eqbPtekZgNTf O6WSASjutfVDn91UZaGarSaBUbuKqy4SanZCkqqPaKTGaGt1LZedgqcRDsQE7d4ts5Z7pAmN5+d NC1WP452M0gA5apAsi49T1u9mit2xwkr3QalgIut4YroO9Hmbu6w8chrNnN5vi41kLkpx9oRkdV A== X-Received: by 2002:a05:620a:288a:b0:92e:f3ca:2ec8 with SMTP id af79cd13be357-930b3e4b8a0mr1508481385a.19.1784576122786; Mon, 20 Jul 2026 12:35:22 -0700 (PDT) Received: from gourry-fedora-PF4VCD3F.lan (pool-173-79-60-52.washdc.fios.verizon.net. [173.79.60.52]) by smtp.gmail.com with ESMTPSA id af79cd13be357-930b545e47bsm957792285a.35.2026.07.20.12.35.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Jul 2026 12:35:22 -0700 (PDT) From: Gregory Price To: linux-mm@kvack.org Cc: Zhigang.Luo@amd.com, arun.george@samsung.com, balbirs@nvidia.com, brendan.jackman@linux.dev, yuzenghui@huawei.com, apopple@nvidia.com, alucerop@amd.com, matthew.brost@intel.com, akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, corbet@lwn.net, skhan@linuxfoundation.org, gregkh@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org, djbw@kernel.org, vishal.l.verma@intel.com, dave.jiang@intel.com, alison.schofield@intel.com, osandov@osandov.com, jannh@google.com, pfalcato@suse.de, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com, pbonzini@redhat.com, osalvador@suse.de, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, gourry@gourry.net, ying.huang@linux.alibaba.com, kasong@tencent.com, qi.zheng@linux.dev, shakeel.butt@linux.dev, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, yury.norov@gmail.com, linux@rasmusvillemoes.dk, longman@redhat.com, ridong.chen@linux.dev, tj@kernel.org, mkoutny@suse.com, sj@kernel.org, jgg@ziepe.ca, jhubbard@nvidia.com, peterx@redhat.com, baolin.wang@linux.alibaba.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, lance.yang@linux.dev, usama.arif@linux.dev, xu.xin16@zte.com.cn, chengming.zhou@linux.dev, roman.gushchin@linux.dev, muchun.song@linux.dev, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, driver-core@lists.linux.dev, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-debuggers@vger.kernel.org, linux-fsdevel@vger.kernel.org, kvm@vger.kernel.org, cgroups@vger.kernel.org, damon@lists.linux.dev, linux-kselftest@vger.kernel.org, kernel-team@meta.com Subject: [PATCH v5 17/36] mm/vmscan: disallow reclaim of private node memory Date: Mon, 20 Jul 2026 15:34:11 -0400 Message-ID: <20260720193431.3841992-18-gourry@gourry.net> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260720193431.3841992-1-gourry@gourry.net> References: <20260720193431.3841992-1-gourry@gourry.net> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Private nodes do not support reclaim by default, so prevent all reclaimers from operating on private nodes. shrink_node() is the common chokepoint for most reclaimers (direct, kswapd, proactive, mglru, etc), so it's the best place to filter. DAMON's proactive pageout bypasses shrink_node() entirely, so we disable DAMON in a separate commit as its own discrete service. Other reclaim entry points are already covered - e.g. MGLRU's debugfs interface rejects nids that are not N_MEMORY (N_MEMORY_PRIVATE is mutually exclusive), and madvise pageout/cold skips private nodes. Signed-off-by: Gregory Price --- mm/vmscan.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/vmscan.c b/mm/vmscan.c index e26c6931f5fde..86b2334c23b98 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -6141,6 +6141,13 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc) struct lruvec *target_lruvec; bool reclaimable = false; + /* + * Private nodes do not support reclaim by default, filtering here + * captures all normal reclaim paths that may attempt eviction. + */ + if (node_is_private(pgdat->node_id)) + return; + if ((lru_gen_enabled() || lru_gen_switching()) && root_reclaim(sc)) { memset(&sc->nr, 0, sizeof(sc->nr)); lru_gen_shrink_node(pgdat, sc); -- 2.53.0-Meta