[PATCH v2 1/3] mm: add vm_normal_lru_pages for LRU handled pages only

[Christoph Hellwig]

On Thu, Mar 31, 2022 at 10:55:13AM +0200, David Hildenbrand wrote:
> > Why can't this deal with ZONE_DEVICE pages?  It certainly has
> > nothing do with a LRU I think.  In fact being able to have
> > stats that count say the number of device pages here would
> > probably be useful at some point.
> > 
> > In general I find the vm_normal_lru_page vs vm_normal_page
> > API highly confusing.  An explicit check for zone device pages
> > in the dozen or so spots that care has a much better documentation
> > value, especially if accompanied by comments where it isn't entirely
> > obvious.
> 
> What's your thought on FOLL_LRU?

Also a bit confusing, but inbetween all these FOLL_ flags it doesn't
really matter any more.