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[173.79.60.52]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-52db62764f2sm1152051cf.30.2026.08.16.17.49.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 16 Aug 2026 17:49:27 -0700 (PDT) Date: Sun, 16 Aug 2026 20:49:24 -0400 From: Gregory Price To: Qiqi Li Cc: linux-mm@kvack.org, 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, 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: Re: [PATCH v5 25/36] mm/memory_hotplug: support N_MEMORY_PRIVATE node hotplug Message-ID: References: <20260720193431.3841992-1-gourry@gourry.net> <20260720193431.3841992-26-gourry@gourry.net> <6840c720-8cb7-46bb-a652-040c130a4427@huawei.com> Precedence: bulk X-Mailing-List: linux-debuggers@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6840c720-8cb7-46bb-a652-040c130a4427@huawei.com> On Thu, Aug 06, 2026 at 11:30:08AM +0800, Qiqi Li wrote: > Hi Gregory, > > On 7/21/2026 3:34 AM, Gregory Price wrote: > > > Add add_private_memory_driver_managed() to let modules hotplug > > memory onto an N_MEMORY_PRIVATE node they control. > > I am trying to understand how the nid passed to > add_private_memory_driver_managed() is expected to be provisioned. > > From what I can see, both node_private_register() and > __add_memory_resource() require the nid to already be present in > node_possible_map. My understanding is therefore that this patch > supports hotplugging private memory onto an existing possible node, > rather than creating a new possible node ID at runtime. > > For example, in the use case I am looking at, the device's private > node is not described by firmware. Would its nid need to be reserved > during early NUMA initialization, or is there another mechanism that > I may have missed? > It would need to be reserved, and you could use numa emulation but that's clunky. I have an RFC for exactly this issue - though i haven't pushed it further yet. https://lore.kernel.org/all/20260610014517.253609-1-gourry@gourry.net/ > Also, could you please Cc me on future revisions of this series? > I would appreciate it and would be happy to follow the work:) > > Thanks, > Qiqi