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[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> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: A833D40010 X-Stat-Signature: aqnk956x31s46c669tad9c68bt5637wq X-Rspam-User: X-HE-Tag: 1784576123-33107 X-HE-Meta: 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 kOivdcFa cK05BTBl6zkR8r3KdYUFXLguIuBbaVpVuOINVcXq4mPFtCKDCui+z0SHuoVm+81OvIhjBtApWhdzFcXcUerDEZ7UY96APKDdzu++JwfnsiWh7PWxHqVI1VlmE/h9F43dglqrb6j+ZIPxBLMnNRZSkwXnw2CXZkQvlul6pYID+mXzzCJJ9jI2vKSRIgBywRdzzth6T7yVktmxpamIhwQzlWeWqfs2wNvq1yr5SqDszQktbksewhdbZixVlLAiK0z8jbLra60r1eSVA8fALZb/fLaX3nalhOwWyqAIcFOywJFB2gRRRwSjDaSejJpLQtGzUpPRCzqYPPzQ5kZLp0ml5YF9QdIARtWD2LMb5Wuw0GWz8yEAOWMdcsJ6wt3iBOKOw55Wa Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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