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Tue, 13 Jan 2026 00:15:23 -0800 (PST) Received: from localhost.localdomain ([240f:34:212d:1:180a:3788:c683:2f64]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-350ff05492dsm657199a91.3.2026.01.13.00.15.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Jan 2026 00:15:23 -0800 (PST) From: Akinobu Mita To: akinobu.mita@gmail.com Cc: linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, hannes@cmpxchg.org, david@kernel.org, mhocko@kernel.org, zhengqi.arch@bytedance.com, shakeel.butt@linux.dev, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, gourry@gourry.net, ying.huang@linux.alibaba.com, apopple@nvidia.com, bingjiao@google.com, jonathan.cameron@huawei.com, pratyush.brahma@oss.qualcomm.com Subject: [PATCH v4 0/3] mm: fix oom-killer not being invoked when demotion is enabled Date: Tue, 13 Jan 2026 17:14:50 +0900 Message-ID: <20260113081453.8293-1-akinobu.mita@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On systems with multiple memory-tiers consisting of DRAM and CXL memory, the OOM killer is not invoked properly. This patchset includes a fix for the issue and an enhancement that makes the issue reproducible with numa emulation. v4: - remove unnecessary include of linux/node.h, suggested by Jonathan Cameron - include linux/notifier.h for the notifier_block, suggested by Jonathan Cameron - typo in abstruct distance value in the commit log and document - add information about supported architectures in numa_emulation.rst - add a code comment in can_demote() v3: https://lore.kernel.org/linux-mm/20260108101535.50696-1-akinobu.mita@gmail.com/T - rebase to linux-next (next-20260108), where demotion target has changed from node id to node mask. v2: https://lore.kernel.org/linux-mm/20251222004834.10539-1-akinobu.mita@gmail.com/T - fix the explanation about cmdline parameter in the commit log - add document for NUMA emulation - describe reproducibility with !mglru in the commit log - removed unnecessary consideration for scan control when checking demotion_nid watermarks v1: https://lore.kernel.org/linux-mm/20251208094028.214949-1-akinobu.mita@gmail.com/T/ original report: - https://lore.kernel.org/lkml/20251022135735.246203-1-akinobu.mita@gmail.com/T Akinobu Mita (3): mm: memory-tiers, numa_emu: enable to create memory tiers using fake numa nodes mm: numa_emu: add document for NUMA emulation mm/vmscan: don't demote if there is not enough free memory in the lower memory tier Documentation/mm/index.rst | 1 + Documentation/mm/numa_emulation.rst | 31 +++++++++++++++++++++++++++++ mm/numa_emulation.c | 26 ++++++++++++++++++++++++ mm/vmscan.c | 17 +++++++++++++++- 4 files changed, 74 insertions(+), 1 deletion(-) create mode 100644 Documentation/mm/numa_emulation.rst -- 2.43.0