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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-483a31f995dsm57350025e9.13.2026.02.20.01.04.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Feb 2026 01:04:10 -0800 (PST) Date: Fri, 20 Feb 2026 09:04:09 +0000 From: David Laight To: Kiryl Shutsemau Cc: lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, x86@kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , David Hildenbrand , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Lorenzo Stoakes , "Liam R. Howlett" , Mike Rapoport , Matthew Wilcox , Johannes Weiner , Usama Arif Subject: Re: [LSF/MM/BPF TOPIC] 64k (or 16k) base page size on x86 Message-ID: <20260220090409.1784bc64@pumpkin> In-Reply-To: References: X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspam-User: X-Rspamd-Queue-Id: 2E0DC14000F X-Stat-Signature: q3ggr9mj54jxrntppdqpk3kconead8e3 X-HE-Tag: 1771578252-289071 X-HE-Meta: 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 F/32BEVH PDveQfQz2mCfQhwWL0Ok2p24kxqFUr8kRDhneoA0ENzwKH1IUovI8s9GSQMMTpwOrdjxMCPq+ZKUYhJxxJQntTLnQPXdDR8sKscFuB6vU6A75CcnFla1T7z61SzyGPbCoxGHCRmRXFNVGskFM2z29bS9gpWU4/mPiFJifjBTYeyyMPUZ7tI33Q8EslkdYRD5G8sS5P35Qy0GUo1KeP6U5IjA5o7qLZroqzNCQQ7JKFTzyOzqxypDv/94F1SHgyxfrqivJgCEIxcir9vbJ033FZOzGRUaWCcSdDOjI2233mrEJ4TwYmweDS3OTngZ0ckvlpNcpJ7tTrQQXN0642NWNZrJkNXJY0Yq6g8MGqn7v9tOpJzjBPuTpWxUekUUyWeXGT0pZsPVOU84nJ9/CFzDUve3nOJ4AH3M75roUMiXlNcwNRoFAqUJjgXUPlzbOhAYfAIQ6GMMXt8fR7aQ= 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 Thu, 19 Feb 2026 15:08:51 +0000 Kiryl Shutsemau wrote: > No, there's no new hardware (that I know of). I want to explore what page size > means. > > The kernel uses the same value - PAGE_SIZE - for two things: > > - the order-0 buddy allocation size; > > - the granularity of virtual address space mapping; Also the 'random' buffers that are PAGE_SIZE rather than 4k. I also wonder how is affects mmap of kernel memory and the alignement of PCIe windows (etc). David