Re: [LSF/MM/BPF TOPIC] 64k (or 16k) base page size on x86

[Kiryl Shutsemau]

On Fri, Feb 20, 2026 at 09:04:09AM +0000, David Laight wrote:
> On Thu, 19 Feb 2026 15:08:51 +0000
> Kiryl Shutsemau <kas@xxxxxxxxxx> 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.

Yeah, in some places we use PAGE_SIZE just because without any reason.

> I also wonder how is affects mmap of kernel memory and the alignement
> of PCIe windows (etc).

Kernel, as userspace, is free to map memory PTE_SIZE granularity.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov