Re: [PATCH] mm: use managed_zone() for more exact check in zone iteration

[Michal Hocko]

On Fri 16-11-18 12:05:04, osalvador wrote:
> On Fri, 2018-11-16 at 10:57 +0100, Michal Hocko wrote:
[...]
> > E.g. memory hotplug decreases both managed and present counters. I
> > am actually not sure that is 100% correct (put on my TODO list to
> > check). There is no consistency in that regards.
> 
> We can only offline non-reserved pages (so, managed pages).

Yes

> Since present pages holds reserved_pages + managed_pages, decreasing
> both should be fine unless I am mistaken.

Well, present_pages is defined as "physical pages existing within the zone"
and those pages are still existing but they are offline. But as I've
said I have to think about it some more
-- 
Michal Hocko
SUSE Labs