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b=lwcGsVlGmcwleSUa+A8hLzj+NGdzH6Y2I1/rOJSzYRIIYezzYMYMPVrPRQ48p6ryN HCeIPZwTqvHv4bxVit2bpZ55mELXNbC8DnshsrQFi3O/nr5a1TOjfhBl4rzNPpYYaG s0IkZTPen5kAJlYWNL6QNcraZhJlNtSCVnW82hygriTiFyfQFrJGRiImoU9gcgIftg 91+c3VMiEF2pVllwdflj8jRMREiydmr57VoaewxsYyrDnc7iwxHs4M43/J1C00L5J2 Kx+/vvUqLJwW10wZhEOwJC5uuoRDHWjXZ1iIR3iQuiqlWCA/7XQkBrG6AWazz4oE5y DAyh7BgcnFbIA== From: Pratyush Yadav To: Shyam Saini Cc: linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, rppt@kernel.org, akpm@linux-foundation.org, kees@kernel.org, tony.luck@intel.com, gpiccoli@igalia.com, bp@alien8.de, rdunlap@infradead.org, peterz@infradead.org, feng.tang@linux.alibaba.com, dapeng1.mi@linux.intel.com, elver@google.com, enelsonmoore@gmail.com, kuba@kernel.org, lirongqing@baidu.com, ebiggers@kernel.org Subject: Re: [RFC PATCH] reserve_mem: add support for static memory In-Reply-To: <20260618224018.117978-1-shyamsaini@linux.microsoft.com> (Shyam Saini's message of "Thu, 18 Jun 2026 15:40:18 -0700") References: <20260618224018.117978-1-shyamsaini@linux.microsoft.com> Date: Tue, 23 Jun 2026 15:10:32 +0200 Message-ID: <2vxzpl1hmmgn.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Stat-Signature: x1hky5cauqz3pwnwyk8ty58r4exq1h4m X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: EE30840013 X-HE-Tag: 1782220237-292162 X-HE-Meta: U2FsdGVkX19YKCeDZ9OTNgNCk4fDV5SDUx+XmSeMviANGE+0QaEWB48YJdtuZo3FxM5xHPj2ATiGlRC5S94xUCZ/5u6gLhBz3QFULcB18TAwTdQlh6S+E84+OA9b0CSc8L0jPp6nZqYwPHez7URjfHVdiyLaRD9xxlo2NpmgxIfvkVIX1/W0laRcdNeDDKsyzs+4sPxWLvTLWJRkEzGGCS7P6aBb+nEEJEE4wRF9FOVUCri1dfYMp24/6K0WUgiikD5sEc04Uz8dPgYNnksNoON7xgyDvzyFEKDoYnFyaayAi+gYjyuYquvmMW0TQ4897w6IW0Y5PSNTNVdMxg3dHZ3jr68thMBsMaaAxthbaDieCXysoBz3kk+k0BQTMndQ71v7zqpVL5D3cRs3h2pg2R4LyuIEAoIjK6WXYQKrpbVupk5SzBOI7SiNhHbzeZ5/FwRVDPAGB8FbJDenVlVPhrUEYUMcyNAREzGt69jBk7qkN7NyQahX+iB7SQVkBgx8MuWCTz/8jdp14eetzhwi63hHxDuac9R0bo3cvl4pZvdxOvnICjU3gEu54ImGf/0AvDm3GSjQm1WRp16ahKscsqgpAWv0BIuoL1Selzvq/3LDV7fZQGUoEB0/S+6Qd5BXH3Usmb1xGU/N550KJ6XMHos6tVzQpp1otI0TmEj5+ghohEQyJsF+ecR3fL8pUoUupIdbxPk8aWRmxmDuwQtGT5pSjyqedPho1LTKyoDOY2QvzazSAyD4JfWYCbTEzYzJUxH2a9iUEBC+YD/2WRHv6hDnpeGJwmOsCwWQyQiADN3chbdPLpcKrakowCgZ6vB9A2cxoqNZQHs5O7vOxYtPhRI8Ly1T9FOy7PFAjxxPelXGihQmVhkDbfO/2ToiSAATmMlThdftalLua7mAVSMxufEQnehk4tkUNXy6LxfjrEjsGmisANjNELTFVsEZjEgBmSi0FNp3/Gck84mqprL AIMsA7rc se0e5hmAakhuWiFsXB7iq5CtoppOaoaWXKrfAuWPc4b8B7X6RbdedcrDwQ1Cia015tEC9U51GE4PhdvSrYOL9bGD7WSYjGpDbXhOnY4/gheVDRmfB+yBkuS8+hHNLtyIzgQJFQeMBoTOV/BFDMF5Ln3MQViA2hqlG/daAoF8Qm4JICsHjiPG23GT3nt7zgB0lJ9LcFe9tfAv/nw7LWbaPo7Ju7Mc9gW2PkWico6mfEzl9qxDlRCNk6942yiEhEtNTf8Ekg94KOrXX5spwrj1XkUS+PAAnspQz4GugZfvsaRLAAb4SDqvjMvLOYQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Jun 18 2026, Shyam Saini wrote: > reserve_mem relies on dynamic memory allocation, this limits the > usecase where memory and its address is required to be preserved > across the boots. Eg: ramoops memory reservation on ACPI platforms > > So add support to pass a pre-determined static address and reserve > memory at this specified address. This enables use case like ramoops > on ACPI platforms to reliably access ramoops region across the boots. Doesn't memmap= do exactly this? How is this different? I always thought the point of reserve_mem was that you _don't_ have to provide an explicit address, one is chosen for your machine automatically. > > Also skip parsing of "align" parameter when static address is passed. > > Example syntax for static address > reserve_mem=4M@0x1E0000000:oops ramoops.mem_name=oops > > Signed-off-by: Shyam Saini [...] -- Regards, Pratyush Yadav