Re: [PATCH V3 09/30] arm/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

Russell King (Oracle)
2022-02-28T10:58:51Z

On Mon, Feb 28, 2022 at 04:17:32PM +0530, Anshuman Khandual wrote:
> This defines and exports a platform specific custom vm_get_page_prot() via
> subscribing ARCH_HAS_VM_GET_PAGE_PROT. Subsequently all __SXXX and __PXXX
> macros can be dropped which are no longer needed.

What I would really like to know is why having to run _code_ to work out
what the page protections need to be is better than looking it up in a
table.

Not only is this more expensive in terms of CPU cycles, it also brings
additional code size with it.

I'm struggling to see what the benefit is.

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