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Mon, 23 Feb 2026 06:13:35 -0500 (EST) Date: Mon, 23 Feb 2026 11:13:29 +0000 From: Kiryl Shutsemau To: "David Hildenbrand (Arm)" Cc: Kalesh Singh , lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, x86@kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , 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: <915aafb3-d1ff-4ae9-8751-f78e333a1f5f@kernel.org> <17c5708d-3859-49a5-814e-bc3564bc3ac6@kernel.org> <32ed82dd-62c3-4a5c-8bae-9465afd7e75f@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <32ed82dd-62c3-4a5c-8bae-9465afd7e75f@kernel.org> X-Stat-Signature: iy6xpig8ykd556amgpqpjit9oj73jqpi X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: D701240005 X-HE-Tag: 1771845219-157580 X-HE-Meta: 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 rHGvmcNA 9VciVpUactSO72ncH80oimZbHR3HoDyubGdcx0JzSnl3KiXSzW6W5p/kYdAD0R94qlzH3PhK7UK/wWgFC19UW0iwaged6sEiabu/me5NNMoGRsxYVQl9yZwA9rFjR7emDKciBu2UuenyZqKCum9anY0ypDba2JS/qCT127bGBE5OPqcDSkPJJkKY6K7RVKawNTJLGSXUCKpj8CWEYtQHDxGZlPQVe4WvJcfgTy56JLVP+0xcBDPQOwuYdxAFNB7IiFO3G7ndpaEwndMPnGk7Ls8NobBMldHX+WJBp 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 Mon, Feb 23, 2026 at 12:04:10PM +0100, David Hildenbrand (Arm) wrote: > On 2/20/26 20:33, Kalesh Singh wrote: > > On Fri, Feb 20, 2026 at 8:30 AM David Hildenbrand (Arm) > > wrote: > > > > > > On 2/20/26 13:07, Kiryl Shutsemau wrote: > > > > > > > > Well, it will drastically limit the adoption. We have too much legacy > > > > stuff on x86. > > > > > > I'd assume that many applications nowadays can deal with differing page > > > sizes (thanks to some other architectures paving the way). > > > > > > But yes, some real legacy stuff, or stuff that ever only cared about > > > intel still hardcodes pagesize=4k. > > > > I think most issues will stem from linkers setting the default ELF > > segment alignment (max-page-size) for x86 to 4096. So those ELFs will > > not load correctly or at all on the larger emulated granularity. > > Right, I assume that they will have to be thought about that, and possibly, > some binaries/libraries recompiled. I think backward compatibility is important and I believe we can get there without ABI break. And optimize from there. BTW, x86-64 SysV ABI allows for 64k page size: Systems are permitted to use any power-of-two page size between 4KB and 64KB, inclusive. But it doesn't work in practice. -- Kiryl Shutsemau / Kirill A. Shutemov