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[96.255.20.138]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-89491823cf0sm23001816d6.8.2026.01.23.11.12.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Jan 2026 11:12:25 -0800 (PST) Date: Fri, 23 Jan 2026 14:12:24 -0500 From: Gregory Price To: Jonathan Cameron Cc: "David Hildenbrand (Red Hat)" , linux-mm@kvack.org, linux-cxl@vger.kernel.org, nvdimm@lists.linux.dev, linux-kernel@vger.kernel.org, virtualization@lists.linux.dev, kernel-team@meta.com, dan.j.williams@intel.com, vishal.l.verma@intel.com, dave.jiang@intel.com, mst@redhat.com, jasowang@redhat.com, xuanzhuo@linux.alibaba.com, eperezma@redhat.com, osalvador@suse.de, akpm@linux-foundation.org Subject: Re: [PATCH 3/8] mm/memory_hotplug: add APIs for explicit online type control Message-ID: References: <20260114085201.3222597-1-gourry@gourry.net> <20260114085201.3222597-4-gourry@gourry.net> <4520e7b0-8218-404d-8ede-e62d95c50825@kernel.org> <20260123182526.00005ee8@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260123182526.00005ee8@huawei.com> X-Rspam-User: X-Rspamd-Queue-Id: 6302C16000E X-Rspamd-Server: rspam07 X-Stat-Signature: 9oftid519rhjkijbohu9kxik6ytst4cz X-HE-Tag: 1769195547-174358 X-HE-Meta: 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 RUt1EDwo SGQZEO0ZVl5IwCQWiVwemAkXLZQPUiZDzvdxd6O8mcjeVSiV5qz0YsNE6DUrolVNlWzhsRJ8e0asyXVAwd68ZKFtrkxoZTuMKwpc3NI2/ef2dk9DsaHu99IXDfIUZyV8d5OYcBb59/ABtJnJQzHU1cItEG57jzEIuO2AmV76Yqvsl5FVcxGo8renOvhCsh0PQrkK+YKli4tXx29c59J6T41m+LmZDXJff0Tjxj8Lac79FYuB6NsnupBtfHKsDIOASgbx3JIW9MuYS3judEizerUHt/ZvDi6v874ID30DeoaopP3BOQBaMyqoUMiJBC4UUEQ6RqqaUujmGB3DDS4h9Qt+LTbd8xp+upTYLsjUm8GUJ084eV2I7BP+uE2YYRdeTPAnUOSpfjhoqbb54neGbXsdfZ5mucDJX7nSkDn78nKxXqUzovZefwG/Vxw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Jan 23, 2026 at 06:25:26PM +0000, Jonathan Cameron wrote: > On Thu, 22 Jan 2026 19:34:10 -0500 > Gregory Price wrote: > > > On Thu, Jan 22, 2026 at 11:41:24PM +0100, David Hildenbrand (Red Hat) wrote: > > > > > > Right, but I don't want any other OOT kernel module to be able to make use > > > of add_memory_driver_managed() to do arbitrary things, because we don't know > > > if it's really user space setting the policy for that memory then. > > > > > > > Ah, this was lost on me. > > > > > So either restrict add_memory_driver_managed() to kmem+virtio_mem > > > completely, or add another variant that will be kmem-only (or however that > > > dax/cxl module is called). > > > > unclear to me how to restrict a function to specific drivers, but i can > > add add_and_online_memory_driver_managed() trivially so no big issue. > > Is EXPORT_SYMBOL_GPL_FOR_MODULE() enough? > Is the issue just that add_memory_driver_manage is `extern`? If so yeah, i can just do the EXPORT_*_GPL path. If you prefer FOR_MODULE, then yes I can do this. ~Gregory