Re: Selecting MMU page size for an architecture

From: Jon Masters
Date: Sun Jan 23 2022 - 21:11:25 EST


Hey Sergey,

On Thu, Dec 23, 2021 at 8:15 AM Sergey Organov <sorganov@xxxxxxxxx> wrote:

> We are building custom CPU and have an option to choose either 4K or 16K
> MMU minimum page size that will then be fixed in the hardware. For
> reasons unrelated to the Linux kernel we'd prefer 16K, but I have some
> doubts.
>
> What pros and cons for kernel and user-space operation 16K pages will
> have over more usual 4K pages? Anything we should worry about?

If you want maximum compatibility with existing source written for
industry at large (e.g. x86/Arm) and even the assumptions in other
devices (and their firmware) you might connect (PCI, or even on-SoC)
then you'll want to go with 4K. However, if I were designing a brand
new architecture today and didn't care about legacy, I would
definitely consider following Apple into 16K.

Jon.

--
Computer Architect