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charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:AQAAfwAHX+yrLndpaKIWAA--.39254S2 X-CM-SenderInfo: pfxlux1drrlkut6sx5pwlxzhxfrphubq/1tbiAQAHAGl2eO0EOAAAsw X-Coremail-Antispam: 1Uk129KBjvJXoW7WF1DKrWUXr4rXF13CF48JFb_yoW8Zw48pa yrKrZYyFnrKFyS9wn29w4DWr15ZFs5CayUCryUuFyxZF4q9F1ftr48tan09a9rJr1xC3W0 qFsFqr93uF95Z3JanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj DUYxn0WfASr-VFAU7a7-sFnT9fnUUIcSsGvfJ3UbIYCTnIWIevJa73UjIFyTuYvj4RJUUU UUUUU X-Rspamd-Server: rspam11 X-Stat-Signature: zu8fufyoudj6uon7xnan9tsnrssz5r58 X-Rspam-User: X-Rspamd-Queue-Id: 1B7B818000D X-HE-Tag: 1769418426-642564 X-HE-Meta: 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 NlUYorEg Imt2GJoC0c6r3451Oz+ZC1mNwSaUwnXdDZNcAZUzS+y5uSgBU8t3TZtb1D5tonPp9LU7iC1bJ4bBX6CQwVVDcehiSi86cMu4h8wjkM8R7y6y+sox6trupAzf0yeljrPRqDFz7 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 1/24/2026 12:46 AM, Gregory Price wrote: > On Thu, Jan 22, 2026 at 04:03:49PM +0800, Cui Chao wrote: >> 2.Why a Kernel Update is Recommended Over a Firmware Update: >> >> In the scenario of dynamic CXL region creation, the association between the >> memory's HPA range and its corresponding NUMA node is established when the >> kernel driver performs the commit operation. This is a runtime, OS-managed >> operation where the platform firmware cannot intervene to provide a fix. >> > This is not accurate > > The memory-to-node association for CXL memory is built by acpi logic: > > linux/drivers/acpi/numa/srat.c > > Specifically: > > acpi_parse_memory_affinity() /* if SRAT entry exists */ > -> numa_add_memblk(node, start, end) > > acpi_parse_cfmws() /* if no SRAT entry exists */ > -> numa_add_reserved_memblk(node, start, end) > > > This patch implies the latter is occurring - as it queries the reserved > block associations - meaning your platform is not shipping SRAT tables > for CXL memory regions. Sorry，my previous statement was ambiguous. What I intended to convey is that the moment when CXL memory is actually assigned to a dedicated NUMA node and becomes ready for use by applications is precisely during the creation of the region. > We have only seen this in QEMU - and this is correctable in firmware. > > But if this is shipped hardware, letting us know the platform lets us > know whether we should backport it. > > --- > > All that said, this does look harmless, and seems reasonable - but the > changelog should reflect what the hardware is doing above. This issue was discovered on the QEMU platform. I need to apologize for my earlier imprecise statement (claiming it was hardware instead of QEMU). My core point at the time was to emphasize that this is a problem in the general code path when facing this scenario, not a QEMU-specific emulation issue, and therefore it could theoretically affect real hardware as well. I apologize for any confusion this may have caused. > > ~Gregory -- Best regards, Cui Chao.