Re: [PATCH] mm/pgtable: Move extern zero_pfn outside __HAVE_COLOR_ZERO_PAGE

[Anshuman Khandual]

On 06/16/2020 01:09 PM, David Hildenbrand wrote:
> On 16.06.20 06:08, Anshuman Khandual wrote:
>> zero_pfn variable is required whether __HAVE_COLOR_ZERO_PAGE is enabled
> 
> Why is that relevant for this patch?

That just states how it is organized right now wrt __HAVE_COLOR_ZERO_PAGE.

> 
>> or not. Also it should not really be declared individually in all functions
>> where it gets used. Just move the declaration outside, which also makes it
>> available for other potential users.
> 
> So, all you're essentially doing is exposing zero_pfn in pgtable.h now.

Right, but it just happens in the process of consolidating three different
instances of 'extern unsigned long zero_pfn' in the same file which are
redundant.

> 
> If everybody should just use my_zero_pfn(), I don't really see the
> benefit of this patch, sorry.

It consolidates redundant declarations and reduces code. We could just have
a comment for zero_pfn stating that it should not be used directly.