Re: [PATCH 18/34] mm: rename NR_ANON_PAGES to NR_ANON_MAPPED

[Johannes Weiner]

On Fri, Jul 08, 2016 at 10:34:54AM +0100, Mel Gorman wrote:
> NR_FILE_PAGES  is the number of        file pages.
> NR_FILE_MAPPED is the number of mapped file pages.
> NR_ANON_PAGES  is the number of mapped anon pages.
> 
> This is unhelpful naming as it's easy to confuse NR_FILE_MAPPED and
> NR_ANON_PAGES for mapped pages.  This patch renames NR_ANON_PAGES so we
> have
> 
> NR_FILE_PAGES  is the number of        file pages.
> NR_FILE_MAPPED is the number of mapped file pages.
> NR_ANON_MAPPED is the number of mapped anon pages.

That looks wrong to me. The symmetry is between NR_FILE_PAGES and
NR_ANON_PAGES. NR_FILE_MAPPED is merely elaborating on the mapped
subset of NR_FILE_PAGES, something which isn't necessary for anon
pages as they're always mapped.