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b=lbORS2221mW4UB7Lc78M075DHdbfBzuAOnIJOGnqtOVAb1UBVbld5xFTahgT2k+4y xyOEhvem8/S2x+iQxNzPgoRodqPGLzza1t781oLP2BVOdW8so6NHogSdOSZp4nOL9V aIzFDiQ8s0swPdHCwrDK9jiCJrAm7jeoXWKv42pOcvPGRACH1HX4BLqyro+ASH+LL8 mo9mDnsMMorr9I86BPO77e4aMCdK6YPxhZttnWgwTL8ETXBSzs5KCqFtVq9hFZp3XP d9+/vnbUvZWv91I7tfhhBFSKcihw4RepYQXh/3Aex++BEDr4q2uNSi5JLiMwybcI5n RzEMzYINQ/Fkw== Message-ID: <793fb531-1fda-4de4-b73f-fb46444ca613@kernel.org> Date: Wed, 28 Jan 2026 00:06:01 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/8] mm/memory_hotplug: add APIs for explicit online type control To: Gregory Price , Jonathan Cameron Cc: 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 References: <20260114085201.3222597-1-gourry@gourry.net> <20260114085201.3222597-4-gourry@gourry.net> <4520e7b0-8218-404d-8ede-e62d95c50825@kernel.org> <20260123182526.00005ee8@huawei.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: DBDF8140008 X-Stat-Signature: kmkwfeocwyg4jq8zma89cyeej6ngmsn3 X-Rspam-User: X-HE-Tag: 1769555168-261294 X-HE-Meta: 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 eojFTuS9 xddtX18J7mylJPGY/dDSb1vvsfYPcGz+5bCCt0vi7pvCh0h6cAROU4oXMrLUtmptT9zGrwfnEO4Rl3aJlg3yxobHLqGiWD3FwT8l7aGi1FrtBGcuOgjOOUgHIcA4F0E/Tzb6SULv2AnJbSDaUdhMWK4fH4+SlggNSUawpTHLMt5bFgE1GyVIPaXZYDMHbQncnQ75avW0PSALFI8Xv36hylq+qVCYlhC8UyAmdxjGmypzdascsQv/GYjTlXnOCGalDoPCVeNCbOYHMevaqGfHvQJU4zj4+uyX2bQT8s6W4jejDPc047g0qBhC51kFXyXcyKZAwAWpw/8XHyQfB1OyuQPNGGAWOEEvYQ8QYrYXP2iuGEQ0= 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 1/23/26 20:12, Gregory Price wrote: > 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: >> >>> >>> Ah, this was lost on me. >>> >>> >>> 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? It's also fine for me to just limit add_memory_driver_managed() to in-tree driver by using EXPORT_SYMBOL_FOR_MODULES. But it might make nvidia unhappy :) So maybe just adding a __add_memory_driver_managed() that gives us more control and using EXPORT_SYMBOL_FOR_MODULES is being a bit nicer for OOT modules. (I guess __add_memory_driver_managed is a better name than add_and_online_memory_driver_managed, thinking about it) >> > > Is the issue just that add_memory_driver_manage is `extern`? Heh, the "extern" is simply not necessary and can be dropped from all such functions. Not related to this. It's all about EXPORT_SYMBOL_GPL allowing anything that claims to be a GPL module to use this functionality. > If so > yeah, i can just do the EXPORT_*_GPL path. > > If you prefer FOR_MODULE, then yes I can do this. I'd go for EXPORT_SYMBOL_FOR_MODULES(__add_memory_driver_managed, "dax") (or would it be the kmem module?) -- Cheers David