Re: [PATCH] mm/page_poison: move PAGE_POISON to page_poison.c

[Wei Wang]

On 02/13/2018 06:16 PM, Michal Hocko wrote:
> On Fri 09-02-18 16:08:14, Wei Wang wrote:
> > The PAGE_POISON macro is used in page_poison.c only, so avoid exporting
> > it. Also remove the "mm/debug-pagealloc.c" related comment, which is
> > obsolete.
> Why is this an improvement? I thought the whole point of poison.h is to
> keep all the poison value at a single place to make them obviously
> unique.

There isn't a comment explaining why they are exposed. We did this 
because PAGE_POISON is used by page_poison.c only, it seems not 
necessary to expose the private values.
Why would it be not unique if moved to page_poison.c (on condition that 
it is only used there)?

Best,
Wei