Re: [PATCH 2/3] mm/mprotect: Use long for page accountings and retval

From: Peter Xu
Date: Thu Jan 05 2023 - 14:30:22 EST


On Thu, Jan 05, 2023 at 09:44:16AM +0100, David Hildenbrand wrote:
> I'm wondering if we should just return the number of changed pages via a
> separate pointer and later using an int for returning errors -- when
> touching this interface already.
>
> Only who's actually interested in the number of pages would pass a pointer
> to an unsigned long (NUMA).
>
> And code that expects that there never ever are failures (mprotect, NUMA)
> could simply check for WARN_ON_ONCE(ret).
>
> I assume you evaluated that option as well, what was your conclusion?

Since a single long can cover both things as retval, it's better to keep it
simple? Thanks,

--
Peter Xu