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Thu, 19 Feb 2026 10:28:04 -0500 (EST) Date: Thu, 19 Feb 2026 15:27:59 +0000 From: Kiryl Shutsemau To: Peter Zijlstra 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: References: <20260219151729.GK1282955@noisy.programming.kicks-ass.net> <20260219152045.GR1395416@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260219152045.GR1395416@noisy.programming.kicks-ass.net> X-Rspamd-Server: rspam09 X-Stat-Signature: oqcs5np9zcdu68mys8xh4o7f6rb773c4 X-Rspamd-Queue-Id: A52BFC000B X-Rspam-User: X-HE-Tag: 1771514889-107891 X-HE-Meta: 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 W91hOEtG IEu0JmvgGoGvXcvGmh4H//eZoXi5pKe0yXwSVphniBlKu22y8loImydeYQDUnI+Uw3mOL9AgGqHVOXHYW75Vbk7ffYnog3YYnZRek3FXuhm/pmVdAr9m8y4v1jupBz6z/rOH3aM4XpoCySTN72ebUEQylvcQ9MIeYSUN9cAfCUjtJXk/lcaOzOAb7iwPOJRe+yxNJwLY+x/uiOQTeUmuutkRQot8COVY/CKJK8fD4hV1KteQa5cv0qXBHYjRa1lMHcDeCg8Zv4I0LlxpFvQ+ckIhqJQF+2MMbwNg6Tv4gzvAUw99A35VZTyGEnoyoHukR7U/n8h/pLp3n5gW9poS4QY1qGg== 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, Feb 19, 2026 at 04:20:45PM +0100, Peter Zijlstra wrote: > On Thu, Feb 19, 2026 at 04:17:29PM +0100, Peter Zijlstra wrote: > > On Thu, Feb 19, 2026 at 03:08:51PM +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; > > > > > > I think we can benefit from separating these two meanings and allowing > > > order-0 allocations to be larger than the virtual address space covered by a > > > PTE entry. > > > > Didn't AA do this a decade ago or somesuch? > > https://lwn.net/Articles/240914/ Oh, 2007. It predates me in kernel. Will read up. Thanks! -- Kiryl Shutsemau / Kirill A. Shutemov