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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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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> 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